...... ,- ,- ,- ,-

COMMUNICATIONS NAVSEA 0967-LP- 000- 0010 SERVICE NOTES

Adjustment Procedurl's for Amplifier Group AN/GSA-33 and the desired peck level in either case being approximately Audio Amplifier AM-413A/G zero vu. The term vu (volume umts) is used exclusively in Background. the remainder of the article in connection with level mea­ Some confusion exists at many activities concerning the surements because the signals to be measured are of a use and proper adjustment of constant level amplifiers. It complex waveform (nonsinusoidol), and, o accordingly, is imperative that the proper adjustment procedures be em­ cannot be measured satisfactorily with a db meter. ployed in order to derive the benefits for which the amplifiers The levels shown in chart No. 1, figure 2 ore indicative were provided. Misuse of a constant level amplifier or im­ of the levels to be expected at various points in the system. proper adjustment of the amplifier can seriously degrade a Since a proper understanding of the function of the two communications system rather than provide the intended controls associated with constant level amplifiers of the improvement. AN/CSA-33 and the AM-413A/G type is essential, o brief A comprehensive article IS currently in the process of explanation follows: The COMPRESSOR control in the preparation concerning the proper use and adjustment of AM-1910/G (a unit of AN/GSA-33) is nothing more than an constant level amplifiers pertainmg to their use in the attenuator and its range is approximately 40 db. entire Naval CommumcatJOn Service. This information will be disseminated tc all activities concerned at a later date. The following mformatJOn is presented, as an intenm measure, to aid activities which hove experiencecl difficulty -- CONDITION A B c with adjustment of AN/CS/1.-33 and AH-413A/C amplifiers NOISE ONLY -10 -30 0 in an operational status. The bcsic elements of the systerr: vu vu -2 vu -10 vu I SEE NOTE I I under discussion are shovm m block diagram form, figure ]. WEAK -4T0-6VU -24 T0-26 -4 TO -6 VU VOICE AVERAGE VU AVG. PEAKING NEAR 0 SIGNAL vu

LEVELS SEE CHART NO. I STRONG +9 TO VU -9 TO-ll VU VOICE +II -4 T0-6VU SIGNAL AVERAGE AVERAGE PEAKING NEAR 0 VU

NOTE I.- FOR RECEIVERS EQUIPPED WITH SQUELCH, ADJUST ·�· ,n_, FOR -10 VU WITH SQUELCH OFF. r�0 0 0 10 1V' ·v· NOTE 2 - USE T S-6291 U OR OTHER VU METER . tOII�It(IIIOII 1.1�11. I

Figure 1. Adju stment Procedures for: Amplifier Group AH/GSA-33 and Audio Amplifier AM-4 13A/G. Figure 2. Chart No. 1

the The system consists of o receiver, u fixed pod at Tne acrion of the COMPRESSOR control in the AM-4l3A/G output of the receiver (not always required), a fixed 20 db amplifier is identical to that in the AM-1910/C although the pad at the input to the amplifier, a constant level amplifier, manner in which the attenuation is accomplished is o little and the load, which in most cases, is either a telephone more sophisticated. So bear in mind, that with either type line or a voice channel in a microwave link. of compression amplifier, adjustment of the COMPRESSOR The reason for installmg a fixed pad at the output of control serves one purpose and that is to attenuate the input some receivers is to allow the final amplifier stage i!l the signal applied to the amplifier. Amplifier AM-413/G does receiver to operate in the most favorable region of its not have a variable compressor control; 1t has only a corn­ dynamic range, without the possibility of exceeding pressor on-off switch; and, for th1s reason, its use in the acceptable levels on the lines feeding the constant level system being considered is not recommended. It can be amplifiers. A 20 db fixed pad 1s requned at the input to used, however, provided a variable ottenuctor, having a the constant level omplHier because the compressor control range of approximately 40 db, is inserted between the 20 db is difficult to set properly scale settmgs between zero fixed pad, shown in figure and the input to the amplifier. at l, and 2 or 3 scale divisions. In other words, the 20 db pad The variable pod then becomes the compressor control. The provides compatnbility between the level of the input signal LEVEL control in either amplifier serves one purpose only. and the most favorable range of the compressor control. That purpose is to establish the amplifier output signal The reason for the constant level amplifier in the system level at a prescribed maximum for the system in which it is two-fold: (I) The gain feature of the amplifier enhances is used. the level of week signals thus processin::J them for satis­ factory transmission over a telephone line and (2) the com­ pression feature of the amplifier automatically limits excessively strong signals to the same satisfactory level;

ORIGINAL AN/GSA-33: 1 ......

COMMUHICATIOHS NAVSEA 0967-LP-000-0010 SERVICE HOTES

Adjustment Procedure (for receivers equippeu wun no1se lo simplify the adjustment procedure, receiver res1duol

silencer or squelch). noise can be used as o signal sour.;e. A typical example L'efore making 'Jny odjust�ent::, b·. �ure tr.e basic ocijustment procedure follows: of the:! proper elements of the system shown in figure ore operotmq 1 Step !. Initial Control settinC]s. satisfactority and that the appropiotr: pads are installed. (a) Turn receiver and orr:pl!ller power sv;itches ON. The receivers listed ifl chart No.2, fu�ure 3, requue a 15 db (b) Turn receiver stlencer or squelch OFF. :nstalled duectly at the output terrnmals. Refer to amplifier compressor tc pod (c) Tum swi h OtJ and turn chart tJo. 3, figure for rJetods concermng the construction 4, COMPHESSOH control maximum clockw1se. of and 20 db prJds. r 15 Step 2. Turn the receiver F�F G/\IN cont ol maximum AF GAIN clockwise and adjust tr.e receiver control for -10 noise output (1n the absence of vu any siqnal) as measured on the line side of the receiver output pad. Use a br1dgmq type vu meter, TS-629/U for example, to make this and RECEIVER TYPE OUTPUT PAD subsequent measurements. lJo not use a db meter. Step the 3. Adjust omplilier LEVEL control for zero vu ANIFRR·26- 27 15 DB noise level as measured at the output of the amplifier. Th!s ANIF RR-30- 31 is \the final adjustment of this control. ANIFRR-49 4. Adjust Step the amplifier COMPRESSOR control for a -10 DB ANIFRR-502 15 vu noise level at the output of the amplifier. This is the R-274BIURR final adjustment of the amplifier controls. Step Switch the receiver silencer or squelch ON, tune in RECEIVERS WITH MAX. OUTPUTS OF LESS 5. a useable .s1gnol and adjust the silencer control in accord­ THAN 60 MW IN 600 OHMS DO NOT REQUIRE PADS. ance with the procedures outlined in the receiver instruction INSTALL PADS DIRECTLY AT RECEIVER book. OUTPUT TERMINALS. Step 6. Check the results acheived. When the above procedures have been followed, the levels in the system l, will be withirt the limits shown in chart No. fqure 2. The object is to set the receiver CJOin controls and the controls on the constant level amplifier in such a manner as to allow Figure 3. Chart Ho. 2 the receiver to operate at near optimum conditions. The weakest useable voice signal (approximately 10 db abcve the noise level) should appear at the output of t>;e amplifier -6 at approximately -4 to vu, peaking near zero, anri all signals of greater amplitude at the output of the receiver compression will be limited in the amplifier to aporoximotely the same value. On some voice signals mfrequent ,.teaks

may roach + l or +/. VIJ. It shouid be noted that it may be possible for si1nal levels meosurt:!d at the input to the amplifier to exceed the levels IJ;easured at the output of the a•nplifier. Tl-.1s 1s coiT.prr,ssion merely indicative of the fact that the ornplifwr is performing its task in the system. SCHEMATIC DIAGRAM Adjustment Procedure (for receivers not equipped with Z IN = Z OUT = 600 � squelch). poruqraph Step 1. Follow the procedures listed in 2 above with the following exceptwns: ATTENUATION R I R2 (a) Omit step 1 (b). the (b) In step 'l, adjust omplifler co��1Pic,LS:i0i, 15 DB 200 220 control for a -20 vu noise level at the output of the amplifler.

It should be noted that o small movement of the :=:ot.1P1>ESS0t\ 20 DB 250 120 control results in o considerable -amount of ottenuotwn, and, accordingly, adjustment of this control should be made USE I-WATT, 5 •t. RESISTORS precisely. Step 2. Check your results. Tune the rece!Ver toG weak signal and again to a moderately strong signal. In either case the levels at the various points in the system should with in chort figure agree closely the levels shown l

ORIGINAL AH/GSA-33:2 . .. .• . . . .. - ,- ,- ,- ,

COMMUNICATIONS NAVSEA 0967-LP-000-0010 SERVICE NOTES

POTENTIAL SHOCK HAZARD IH POWER SUPPLY PP-3565/ GRC-lOOA Activities using Power Supply PP-3565/GRC-lOOA in Radio Set AN/MRC-97 are cautioned not to attempt to ground p in "8" of primary power connectors J-501 and J-502. Reference should be made to NAVSHIPS 94590, Technical Manual for AN/MRC-97, page figure schematic 4-6, 4-4, diagram for Power Supply PP-3565/GRC-lOOA. Recepta­ cles J50l and 1502 on front panel provide for input power, llSVAC or 230VAC, to transformer terminal board T850l. and no ground is provided at the primary terminals of trans­ former TSOl this optional operation. It can be with type seen from the power supply schematic that grounding pin

"8" of llSVAC receptacle J502 will introduce a potential shock hazard.

ORIGINAL AN/MRC-97: 1 ......

- - - - , , , ,

SERVICE MOTES NAVSEA 0967-LP-000-001 0 COMMUHICATIOH S

AH/P RC-6 REPLACEMENT CAPACITOR C-43

The replacement capacitor C-43, part of the ANIPRC-6, is too large to installed in the space allocated. Accord­ be ingly, the Electronic Supply Office has initiated action to stock the following capacitor: N5�10-726-1384, 15000 J-4-Lfd percent, 100 VDC, molded plastic case. ±lO 0.175 diameter by 1-l/16 length. inch

ORIGINAL AH/PRC-6:1 I' ...... ,- ,- ,- ,-

SERVICE NOTES NAVSEA 0967-LP-000-001 0 COMMUHICA TJONS

AH/PRC...a, AN/PRC�, AH/PRC-10 TOOLS FOR SERVICING AND MAINTENANCE

The Bureau has received infonnation from the Signal Corps describing the fabrication of the dnssis holder, a fast-tuning knob, a calibration tool, and an alinement tool for servicing and maintenance of AN/PRC-8, AN/PRC-9 and AN/PRC-10 equipments. This information is sum­ marized for use by ships and activities desiring to fabricate these items. The chassis holder should be fabricated in accordance with Figures l and 2. This stand will hold the chassis safely and securely while servicing. It permits easy access to both front and bock of the set for metering and checking test points. The following material is required for fabrication: 4 feet of l/2-inch angle iron; l/2-inch steel plate, lO inches

wide x 16 inches long; 3/32-inch steel plate, 2 feet long x 3/4 inch wide; l-inch steel rod, 6 l/2 inches long. The spring clamp (Signal Corps Stock Number 626918-8) should Figure 3 be either bolted or welded on the two end pieces. (See Figure 3 for completed stand and calibrating tool). Details of the fast tuning knob, which should be used to tum the tuning knob of the receiver transmitter, are shown in Figure 4. Its use prevents possible injury to fingers,

IMINI CU.. TO II eO&. TID 0" .ILDIO SlOE: v.r.w . ....•;.,IZitll- I ! � -� ;� [0+--� -- :::�o-r�·- :� �--- 1 .. AHGLf JJtOH ' l�t-- "z• ' �· -·------: r- J .. e''l(� ;

t FAST TUNING KNOB " FIGURE-+ •- Dt110tn loeotlo.t of wtfds

FIGURE ·1

and enables fast tuning from one end of the dial to the , .. other. The calibrating tool, Figure may be fabricated from 5, 1/8-inch sheet steel, l l/4 inches wide x inches long. ''" 5 Use of this tool eliminates the necessity of holding down .,4· , •• L.__ the calibrate ON-QFF switch by hand. The present practice 1 is to use both hands to calibrate the radio set and to use the chin and shoulder to hold the handset to the ear when 10' 1 a tr: l ]f) tuning. Jll£ Use of the alinement tool, Figure 6, saves time when \_�;.UOGU INON servicing the equipment and eliminates the necessity of selecting separate wrenches and screwdrivers. It is a four­ PLAT[ in-one tool containing all the individual items required in j the alinement procedure. Based on material published in S.C.E.L. ''Maintenence FIGURE-2 Information Bulletin, MIB-125".

ORIGINAL AH/PRC-8:1 ...... - ... - ... - ... -

COMMUHICATIOHS NAVSEA 0967-LP-000-0010 SERVICE NOTES

6.

CALIBRATING TOOL FOR RADIO SETS AN/PAC· 8·;9,1( ALIGNMENT TOOL

Figure6 FIGURE- 5

AH/P RC-8:2 ORIGINAL ...... - ..- ..- ·,-

COMMUHICATIOHS NAVSEA 0967-LP-000-0010 SERVICE NOTES

Trons•itter·Receiver AH/PRC-39-Modification of Case to p.,.it Tuning of Final Tank Circuit

The Bureau of Ships has been notified by NAS Bruns­ wich that difficulty exists in tuning the final tonk circuit of the AN/PRC-39. Each time the metal case is removed and replaced, the copacity effect of the metol case will de­ tune the final tonk circuit. Drill a hole of sufficient size in the case directly over the final tonk circuit to allow the final tonk circuit to be resonated for maximum RF output upon reinsertion into the case. This hole, when not in use, is sealedwith a rubberized knock-out plug to maintain watertight integrity of the equipment. Drill a 314-inch-diometer hole in the aluminum case directly over the final tank circuit in accordance with figure 1 of this article. Insert a 3/4-inch rubberized knock-out plug into the hole. The stock number of the plug is: KZS340-893-8798. (608)

···l I:

,. ,_ 18

fl ..re 1. Case -dificatlon AH/PRC-39.

I I .j I I I

AH/PRC-39:1 I ORIGINAL I' ......

COMMUHiCA TiOHS NAVSEA 0967-LP-000-00iO SERViCE HOTES

POTENTIAL PERSOHHEL HAZARD IH MERCURY ll. Cement the one-inch thick polyurethane pad BATTERY PACK (FSH 1H61�-075-3497 OR FSH supplied into bottom of case, using a suitable adhesive 1 H6135-075-3497) to hold it in place. Activities using the AN/PRC-40(AX) transceiver are 12. Position the power cable and fuse holder so as cautioned to examine all of the subject batteries currently not to catch on the side of the carrying case and slide the in use or in storage. There is a possibility of a swelling radio into the case. (l7S) condition which may result in an explosion of the battery pack. If distortion or swelling is noted, the battery should be appropriately disposed of, eithEr by burial in a secluded area away from all personnel or by dumping at sea.

Changed Item of Supply for AH/PRC-40AX-Piastic Enscapsuloted Battery Replaced by Battery and Battery Ho lder The purpose of this change is to reduce cost of support and e!Jminate a personnel safety hazard. The plastic encapsulated mercury oottery FSN

1N6135-075-3497 is replaced by a mercury battery in a paperboard cover Jr!6135-94!-6034, anJ a oottery holder FSN lN6135-999-4649. Tne anticipated life of the oottery holder is equal to that of the eqUipment. Therefore, the battery holder is not expected to require replacement after the mitial mstallation. A l/2 ampere fuse FSN 9NS920-28l-0224, retained in an in-line fuse holder FSN 9NS920-l99-9235, is added to the battery circuit. This fuse provides protection from possible explosion of the battery in the event of a short circuit w1thin the equipment.

Procedure: l. Remove radio set from cabinet. 2. Disconnect power cable from oottery and chass1s, and retain cable. 3. Cut one wire of the two-wire power cable, ret­ ained in above step, at its midpoint (approximately 3-1/2 inches from oock of five-prong plug.) 4. Insert the in-line fuse holder FSN 9NS920-199-9235, "tadoring" bath ends of the wire cut to accomodate the fuse holder neatly and solder the connections. S. Remove and retain the two screws holding battery to chassis. Discard battery. 6. Use the two screws retained in previous step to attach lower tray assembly, the one with large bracket, in place of the oottery so that the oock of tray is against the chassis. Insert l/2 ampere JAG fuse FSN 9NS920-28l-0224 7. into fuse holder. Connect cable to battery. B. 9. Place battery into tray attached to chassis and fasten the other tray assembly in place, usinq self tapping screws supplied, so that battery is held between the two trays of the oottery holder. 10. Plug the remaining end of power cable into chassis.

ORIGINAL AN/PRC-40: 1 ......

COMMUNICAT IONS NAVSEA 0967-LP-000-0010 SERVICE NOTES

AH/PRC-41 and AH/PRC-47-BB-451/U Battery; Used with a #10 drill bit, Use a 6-32 tap to remove with Radio Sets the broken ceramic screw and to clean out the Storage Battery is a silver-zinc, alkaline BB-451/U threads. Insert the new ceramic screw and oottery which requues special charging precautions for tighten very carefully with a screw-driver optimum cyclic life. All charging should be done with the which is inserted thru the drilled hole. This oottery charges designed for this purpose, either PP-3240AIU hole will not affect the operation of the RF or Alternate charging procedures are discussed and power amplifier module but will reduce the PP-4567/U. the Technical Manual for Storage Battery time required to make the repair. Implementa­ m BB-451/U, but they are not recommended unless tion of this modification is recommended for TM-04072A-15/!B, / extreme care exercised and unless an urgent requuement all Radio Sets AN PRC-41 which require re­ is placement of the ceramic screw in grid stator exists. assembly (lAS Holders of earlier versions of this techmcal manual MP30). (8 )r,J should obt01n the revision, because significant mam­ "8" tenance informatiOn has been incorpofiGted into this AN/PRC-41 Radio Set-Charging of Batteries, 'eViSi0n. (681) BB-451/U

AN/PRC-41 Radio Set-Ceramic Screw Replacement in The purpose of this article is to advise R-F and Power Amplifier Module AN/PRC-41 users of battery chargers which may be us ed with the BB-451/U. Battery chargers PP-3240 /U and PP-3240A/U Activities servicing Radio Sets AN /PRC-41 are the original chargers used with the silver­ are advised of a modification to the RF and power amplifier module (lAS) which permits zinc battery BB-45 1/U. Charger PP-4567/U was replacement of a ceramic screw in the grid procured by the Marine Corps for use with BB-451/U but should not be ordered or used in stator assembly (lAS MP30). Access to the Navy applications . Where a replacement charger screw is normally blocked by the module top is �equired by Navy activities, the acceptable plate (lAS MP34) and requires disassembly of be the module to replace in the event of failure. replacement is PP-6241/U which should Access can be obtained by drilling a hole ornf>rPd undPr stock number 4G- 6130-00-106-6445 through the top plate, as shown in figure 1. (ElB 959)

@@@@ � � � J5-V4 CATHOO£ ® I I I J4·Vll 6ftl0 --�

Jli-Vll CATHOOE <: �< < : =-��';.�'

=- ,. � Oftlll.IO o i o 7 � � if' � x• V �.,�:_�o< < @ I Oe:J� 0 ftCVft ltl" AMPL- a X IIITft &21·00.1-00 5 JIO JII·AVC J8 - v + @ @ @ 0.4& @@ ...�.----- PA PLATE CURftENT --- 3.37511� �----�-�1

Figure 1. Location of Drilled Hole m Module Top Plate

OR IGINAL AN/PRC-41 :1 ......

COMMUNICATION S NAVSEA 0967-LP-000-001 0 SERVICE NOTES

AH/PRC-41 and AN/PRC-47-88-451/U Battery; Used with Radio Set See article in AN/PRC-41 section under the same title. (681 )

..

ORIGINAL AN/PRC-47:1 ...... - ,- ... - ... -

COMMUN ICATIONS NAVSEA 0967-LP-000-00!0 SERVICE NOTES

AN/PRC-96 Radio Set-Lithium Battery Safety Precautions

This article provides safety precautions intended to prevent the possibility of personnel injury or equipment damage due to incorrect use of lithium batteries installed in the AN/PRC-96 Radio Set. The following precautions should be taken: 1. If a battery cell in the AN/PRC-96 becomes weak and requires replacement, replace both battery cells. Never use a partially dis­ charged lithium battery cell in series with a fully charged cell. 2. Do not use the AN/PRC-96 lithium bat­ teries in any other equipment. 3. Lithium batteries are potentially dangerous. Do not abuse, short circuit, re­ charge, or expose the battery to high temper­ ature or fire. 4. When reinserting the radio set into its storage case, ensure that the ON/OFF VOLUME switch is not inadvertently turned to ON by the packing material. 5. Ensure that spare batteries, both new and used, are individually placed in a plastic bag and sealed, or individually wrapped in an electrical insulating material. A field change kit, to be announced in a future EIB, will provide a safer replacement lithium battery and instructions for disposal of present lithium batteries used in the AN/ PRC-96. Until publication of future instruc­ tions, mark the used batteries "Discharged- Do Not Use." At sea, discharged batteries should be removed from the plastic bag, and disposed overboard in deep water (in excess of 500 feet) outside the prohibited zone (SO mile limit). Do not store for shore disposal. For shore disposal, lithium batteries should be buried in controlled hazardous waste landfills. (See NES0-20.2-011, Hazardous Waste Disposal Guide. (EIB 975)

ORIGINAL AN/ PRC-96: 1 ...... ,- ,- ,-

COMMUNICATIO�S NAVSEA 0967-LP-000-0010 SERVICE NOTES

SAFETY NOTICE-PRECAUTIONS FO R INSTALLING GLASS FILTER GLO BES IN AN/SAT-2 AND US/X-3A INFRARED TRAN SMITTING SETS

A potential safety hazard exists Infrared Transmitting m ..:iet AN/SAT-2 and in Infrared Tronsrrd ttmg Set US/X-3A. A casualty occurred to a newly Installed AN/SAT-2 equip· ment during its test. The gloss fllter qlobe on or;e milia! yard arm beaoon exploded vwlently alter about two minutes of "locked-key" operotJon, scattenng jagged gloss irog­ ments over a radrus of 25leet. Fortunately, no personnel injury resulted, however the tlymq qlass coulci easily have caused senous harTrt to anyone withm range. It is be­

lieved that the casualty resulted !rem a flaw m l he glass oombined With the pressure of heated aH trapped inside the beacon which Is waterl!qht. The mternal air pressure would acoount for the explosive v wlence of the fmlure. The filter globe is identified as Part 0-103 m NAVSHIPS 0957-069-9010, Techmcal Manu

a. Examme each glohe carefull'f tor tlaws, chips, cracks, or cieep scratches. b. Install the')lobe exactly as shown In NAVSHIPS 0957-069-9010. Make sure the gasket Is strmght and that the wmg nuts are tii]htened down uniformly and only hand til]ht. not use wrench. Do u c. Test the newly installed globe by burnmg the beacon lamp in the "steady source" position lor at least three, ten-minute penods WIth a lrke time between perioos for cooling. d. Worn personnel to stand u the test. d eo� d rmg e. Any casualties should be reported promptly to the Naval Electronic Systems Commend.

ORIGINAL AN/SAT-2: 1 ...... - ... - ... - ...-

SERVIC E NOTE S NAVSEA 0967-LP-000-00 10 COMMUNICATIONS

TONE MIXING ON UHF TELETYPE THROUGH CONTROL When this condition exists, excessive.attenuation to the UNIT C-492/SG incoming audio gain at the radio receiver is necessary. When the receiver gain is increased, noise may be intro­ Recently, several reports have been received regarding duced into the Radio-Teletype Terminal equipment that will difficulty with the Model transmitter when used in con­ TDZ cause reduced operating efficiency. The Discriminator fitter should checked from time to junction with the AN/SC'£:-1 terminal equipment and type be C-492/SG teletype-control unit. time to insure that the resonant frequency is within plus or

The difficulty arises when the Send-Receive switch in minus 5% or 500 and 700 cycles. · the control unit C-492/SG is thrown the Send position, to thereby causing the MCW oscillator tone the to mix in TDZ ADJUSTMENT OF SIGNAL INPUT LEVEL with the tone output of the AN/SGC-1. This results in

tones other than those desired being transmitted. Operators may have noticed that the Red-Receive panel Under normal conditions where an M-15 teletypewriter light of Radio-Teletype Terminal Set, AN/SC'£.-1( ), some-­ is used for UHF communications, one of the following rem­ times is illuminated even though no teletype signal is being

edies will found satisfactory. received. The probable sources of this trouble are either · be interference, excessive ripple in the power supply the (a) It the teletypewriter in question is used for UHF of communications only, the Send-Receive switch and carrier­ AN/S(',C-1( ) or its associated receiver, or a high noise control cootacts of the control unit C-492/SG should not be level from the output of the associated radiQ receiver. The connected andthe signal line should go directly from the latter condition is the most probable cause of trouble and it

printer the teletype panel, leaving the only function of is generally brought about through an improper setting of the to the control unit to tum the transmitter power on and off. It squelch crntrol on UHF receivers. The squelch level of the should noted that the carrier-control feature bf control associated receiver and the Rec-level attenuator of the be unit C-492/SG is not required as this function is controlled AN/SC'.C-l() should adjusted to eliminate this trouble. be automatically by the AN/SC'£:-1 terminal unit. (b) In a second system, where the teletypewriter might AN/SGC-1 ADJUSTMENT AND OPERATION also used ·in HF receive only or HF send-receive cir­ be cuits; C-492/SG control unit should be wired in the Two predominant causes for improper operation of Radio­ the normal manner, that is with the signal line and carrier con­ Teletype Terminal Sets AN/SGC-1( ) are incorrect setting of trol circuit fed through the control unit. When this condi­ the Mark Oscillator, Frequency-Adjust Control and excessive tion exists, instead of throwing the Send-Receive switch to noise from the associated receiver. The Mark, Frequency­ the Send position when it is desired to communicate on UHF, Adjust Control should adjusted as indicated in In­ be the simply throw it to the Receive position and perform the struction Book for AN/SGC-1 (NAVSHIPS 9ll52) and AN/ necessary patching in the -23/SG teletype panel. This IT SGC-lA ( NAVSHIFS 91:£)3) . If an accurate test oscillator is possible since the printer and keyboard of a M-15 are is not available, adjust the control to the midpoint its of connected in series. physical rotation. The procedure outlined in NAVSHIPS Each of these systems, the conditions of which might be 91503 should be disregarded as it may result in erroneous common in certain ships, has merit. However, it is believed adjustment. that the latter method will be found more satisfactory Spurious noi;;e and static may lock the terminal the in in that it allows the teletypewriter to operate other circuits in receive conditiw which prevents the terminal from switching also. automatically to the send position. The squelch or silencer circuits of the associated receiver should be adjusted so WIRING DIFFERENCES OF AN/SGC-1 AND AN/SGC-1A that no audio -output is supplied from the receiver until the associated transmitting station goes on the air. Care must Due to an internal wiring difference, chassis and cabi­ be taken to make sure that the adjustment of the squelch nets of the AN/SC'£:-1 and the QN/SC'£-lA radio-teletype circuit does not lower or increase the sensitivity of the terminal sets are not interchangeable. Subsequent to a receiver excessively. field change, all installation and maintenance activities The following is the proper procedure lor adjusting should not interchange chassis and cabinet of this equip­ the squelch control: ment. a. Rotate the control to the least sensitive squelch BAND PASS FILTER (SYMBOL NO. Z102) IN AH/SGC-1 position of the receiver. AND AN/SGC-1A b. With the transmitting station off the air, rotate Unsatisfactory performancehas beenreported in the the squelch control slowly toward the greatest above equipments die to defective Discriminator 2102. In­ sensitivity of the receiver until the Red-Receive struction Books, NAVSHIPS91152 and NAVSHIPS 91503 lamp of the AN/SC'.C-1( ) is illuminated. show the characteristics of the filter at 500 and 700. cycles to have zero attenuation. Indications are that certain capac­ Back off the squelch control slowly until the c. itors used in the filter networks have increased in value Red-Receive lamp is extinguished. sufficiently to lower the frequency of resonance.

ORIGINAL AN/SGC-1:1 ...... - ... - ...-

COMMUHICATIOHS NAVSEA 0967-LP-000- 001 0 SERVICE HOTES

AH/SGC-1() LOSSES IH FILTER Z102 voltage drop across Zl02, which is shown in figure 5-B of N AVSHIPS 91152 and 91503. Reports from using activities have stated that the in­ The second requirement of filter Z1 02 is to attenuate sertion loss of filter Zl02 in the AN/SGC-1( ) exceeds the the undesired frequency. Figure 2-6, of NAVSHIPS 91152, values shown in figures 2-6 of NAVSHIPS 91152 and 91503. indicates the loss to be about 15 db. Paragraph 4 of sec­ The electrical configuration of filter Zl02 is shown in fig­ tion 2, NAVSHIPS 9ll52, states the attenuation to be about ure 1 of this article. 18 db. The test data from METU-5 indicates the rejection The actual insertion loss is greater thanAndicated in of the mark sign by the space filter to be about 20 db and figure 2-6, since the graph is intended solely as an aid in the rejection of the space sign by the mark filter to be about 11 It will be noted that the maximum attenuation understanding the theory of operation. The data on the db. graph should not be used to determine the performance of {)f the space signal by the mark filter was obtained when the filter. the frequency of peak response of the mark filter was cen­ The real and apparent losses through the filter, when tered on 695 cps. measured with an electronic voltmeter such as the AN/USM- The limits for rejection were not defined in the original 34, may total 10 to 12 db or more. The real loss through the specification. Using activities have indicated that satis­ factory operation may be obtained with 12 attenuation. filter is stated in the design specifications for the equip­ db ment. The design specifications read: To determine the performance of filter Zl02, the test a. The Mark filter shall present not more than 5-db at­ equipment should be connected as shown in figure 2. One tenuation at 700 cps. In addition, the attenuation curve 'Jacuum tube voltmeter may be used for all tests. The test shall be approximately symetrical around 700 cps. procedure follows: Apply power to the AN/SGC-1( ) until the ter­ b. The Space filter shall present not more than 5-db at­ !. tenuation at cps. addition, the attenuation curve 500 In minal equipment reaches normal operating temperatures. A shall be approximately symmetrical around 500 cps. Test minimum of 2 hours is usually required. data on the 10-AN/SGC-1( ) equipments were taken by 2. Remove power from the AN/SGC-1( ) when mak­ METU-5 and forwarded to the Bureau of Ships; test results ing all test connections or adjustments. After the test are given in Tables I and II. connections or adjustments have been made, apply power. The test data indicate that the frequency of peak response Observe all safety re::�ulations. on almost all filters has drifted downward. However, aH 3. Remove V-101. filters have less than 5 db loss at the operating frequency 4. Connect the au dio asci !later to point A through except the mark filters far equipments 227 and 338. an 0.1 - mfd de blocking capacitor. Make sure that the In addition to the power consumed in the filter, another audio oscillator is terminated in its correct impedance. power loss of 7 db is incurred when the harmonics of the 5. Connect the V. T. V.M. to point B. Set the selec­ fu ndamental frequency are removed from the square wave tor knobs on V.T.V.M. for the highest voltage on the ac output of V-102. When these losses are added, the total range. may be 10 to 12 db. This value corresponds closely to the 6. Apply power to the AN/SGC-1( ). Adjust the frequency of the audio oscillator for 500 cps, ±5 cycles. Increase the output from the audio oscillator until the r------1 voltmeter at B ceases to rise in proportion to the input I I voltage. Note the voltage at B. l SfW:E FILTER I 500 C.P.S. : 7. Reduce the output of the audio oscillator until I the voltage at point B decreases to l/3 the value noted in I step 6. This insures that the input to the filter is a sine I I wave and not a square wave. Under this operating condi­ I tion, the measured attenuation is the real loss of the til- I ' ter. ' B. Measure and record the voltages at points B, C I I and D. 9. Adjust the frequency of the audio oscillator for MARK F1LT£R 700 cps, ± 5 cycles. Adjust the output voltage until the 700 C.P.S. �atFD .� voltmeter at point B reads the same as in step 6 above. 12.1MM .ll .• MH 10 . Measure and record the voltages at points B, C, 10,000 A /WilT L 10,000 A OUTPUT .. P'£DM« :Ot... 1/IIPt:DMCl and D. The insertion loss of the mark filter is determined by dividing the voltage at point C in step 10 by the volt­ T .. ,D I age at point B in step 10. The loss should not exceed 5 • db. Table III shows db values for various voltage ratios. ! The insertion loss of the space filter is determined by vi ding the voltage at point D in step 8 by the voltage at eli I point B in step 8. The loss should not exceed 5 db. II ·------The rejection of the space frequency by the mark filter - - Z-102------.J Fie.I ELECTRICAL eotii'IIURATION 01' FILTER is found by dividing the voltage at point C in step 8 by

AH/SGC-1:2 ORIGINAL ...... ,- ,- ,- ,. . [ SERVICE HOTES NAVSEA 0967-LP-000-0010 COMMUHICATIO NS

the vo t e at point C in step 10. Th e loss should be 12 repairs ore made by external capacitors in se­ l ag connecting db or greater. ries with the filter. The schematic diagram of the connec­ The rejection of the mark frequency by the space filter tions is shown in figure 3. The values of capacitors, which is found by di viding the voltage at point Din step 10 by will gi·Jf optimum performance, are best determined by trial and error. To select the range of values to be tried, the vo ltage at point 0 in step 8. The loss should be 12 IV db or greater. Table may be used as a guide. The test procedure, to determine the performance of the filter repeated ll. Adjust the frequency of the audio oscillator should be from 400 to 800 cps in increments of 10 cps and repeat after each group of external capacitors have been connect­ step 9 for each setting of the oscillator. Record the fre­ ed into the circuit. If an improvements is noted, the capac­ itors may be bolted to the chassis and any splices cover­ quencies at which the voltage on points C and 0 ar e at a maximum. ed with spaghetti. The physical dimensions of the capac­ If the insertion loss of t he filter at the pass band ex­ itors, are shown in figure 4. ceeds 5 db or if the rejection of the undersired frequency Any equipment modified by these emergency repairs 12 is less than db , the filter is defective and should be re­ should be tagged andidenti fied so that it can be properly placed. repaired at the earliest opportunity. The changes should be If a replacement is not readily available, emergency recorded on the Electronic-Equipment History Cord, NA V­ repairs may be made on some filters where the frequency SHIPS 536. of peak response has shifted downward. The emergency

Table I Electrical Characteristics of Space Filters in the AN/SGC-1

Equip Freq of peak Insertion loss Pass band Freq Insertion loss in Ser. response in in DB at peak where Atten is DB at mark Freq cps response 5 DB or less of 700 cps - 227 485 2. 8 385-525 25 229 420 2. 3 385-525 24 230 420 3. 8 385-505 25 231 435 2. 5 400-535 23 232 505 3.0 395-535 24 233 425 2. 4 390-530 24 236 400 3. 6 375-500 26 238 420 3. 9 390-515 25 363 430 2. 5 395-530 25 Table II Electrical Characteristics of Mark Filters in the AN/SGC-1

Equip Freq of peak Insertion loss Pass band Freq Insertion loss in Ser. response in in DB at peak where Atten is DB at mark Freq cps response 5 DB or less of 500 cps

227 650 3.4 590-680 14 229 640 3. 7 620-710 18 230 665 3. 8 600-700 15 231 695 3. 8 615-725 18 232 610 4. 5 590-700 15 233 620 4. 0 590- 700 15 236 600 3. 5 570-695 17 238 635 4. 0 600-705 15 363 675 3.8 600-705 17

ORIGINAL AN/SGC-1:3

69 ......

... - ... - ... - ... -

COMMUNICATIONS NAVSEA 0967-LP-000-001 0 SERVICE NOTES

+225V.

V.T.V.II.

Rll7

.___ c�I O· �s--�®��====�--�

VIOZ IZAU7

Rll9

.I MFO

V.T. V.M.

TERMINATING RESISTOR FOR UOIO OSCILL­ � TOR 4---�

FIG. 2 CONNECTIONS FOR TEST EQUIPMENT

Table IV

Filter Freq of peak Suggested values of external capacitors re!=!nOni=!P C1 I C2 I C3 I C4

Mark 550 .01 .01 Mark 590 .01 .02 Mark 630 .02 .02 Mark 650 ..02 . .05 Mark 665 .05 .05 Mark 700 None None Mark 725 No Corr. Mark 750 Possible Space 420 .02 .02 Space 450 .05 .05 Space 500 None None Space 525 No Corr. Space 550 Possible

AN/SGC-1 :4 ORIGINAL ...... - -...- ...- ...-

SERVICE NOTES NAVSEA 0967-LP-000-0010 COMMUNICA TIOHS

Table ill

Voltage Decibels .... Ratio

1. 00 0 ""' 0.89 -1 ..•. 0.79 -2 0.70 -3 .... 0.62 -4 0. 56 -5 0.50 -6 0.44 -7 .out· 1. AOO C.VACITCWII Ct eCt tiU fAit..( ISIT O llt.tiM TN( ,fii(UUINCT 0# TN( · - 0.39 -8 I. = C��OAI Cl • C4 IU:l TAIL( IllI TO IIA.IS( TH( "tlQUlltC1' 0,. TH( IMCI rtLllll

0.35 -9 "'· :S CIOMIICTI OII 0' UTIIIIIAL CAI'ACITOIIS ' 0.31 -10 ... :t.. - j 0.28 -11 0.25 �12 0.22 -13 0.20 -14 0.17 -15 0.16 -16 �.15 -17 p. 12 -18

_.

.___--tt- -t----

FIG. 4

PHYSICAL DIMENSIONS OF EXTERNAL CAPACITORS ., " CAPACITOR DIMENSION A DIMENSION "8" CAPAC ITY " " CP28AIEF 103K I 5/16 1/2 .OJ MFD " CP 2 SAl EF 203K I 13/1 6 1/211 .02MFD 11 CP2 BAIEF 503K 111 /1 6 11/16" .05 MFD

ORIGINAL AN/SGC- 1:5

'......

SERVICE NOTES NAVSEA 0967-LP-000-0010 COMMUNICATIONS

modul ation will occur the range between sh1ps will be AH/SGC-1 TOHE MODULATEDTEL ETYPE and decrea sed for rel iable commumcotrons. The output audio

The AN/SGC-1 tone modulated teletype CJ rCU1 ts ore from the SGC equipmen t shoulcibe set to furni sh the some reliable and netoble" types. Thr s type c1rcur t 1 1 cieal fo r level ol audiO rnto the oudro transrrd tters that the remote 11 s ORSETES nets w1 th1n a task group or task un1 t. For this radiophone units urnr sh. With level s properly set and the f reason, the operator/technician should understand the use function switch in AUTO, theSGC equipment can furnish ol the equipment m orcier to ')et the most trorr, the equipment very rel table co mmunications for your ship. at all times. There no better way to find the cap abi J ty IS ! Don't overlook the ''sp read'' between murk and space of an equipment than hy actual operution. Th1s con done frequencr Ps on the SGC u rpmen t; 700 hz for mark and be eq ::00 easily between two sh1ps 1n port or ot sea, using on author­ hz for space qives a spread ot200 hz. The norrr,al spread ized UHF trequency by op erators ',vho want to become for low frequency tee type is hz and this g1 ves ano ther 170 proficient. abi l ty the SGC. The equ1prnent mn be used to ccp t tor The AN/SGC-1 1 sa OC-to-oudw converter 1 n the copy 170 hz sh ift low-trequency teletype such as u broad­ tmasm rt rr.oae. It rece1ves CC ! rorr, the teletype machine cast . Just tune up a rPCel ver to the red s1gnal and set ciPSJ and converts this DC rnto auillofreque nCies tor :uther trans­ the BPO on the receiver so that the oud10 !rorr, thP receiver mission by a radio t an srn r tter, usually UHF. The audio is p roximately hz for hz the sp ace r cp 700 rrmk and SOD to r tone for a teletype mork rs700 hz and the space frequency IS and feed th1 s si qnal rnto the SGC eqUipment. Place the

In the recei ve mode, the uipment is an audJo­ functio n swr tch to rece1 ve and plug a teletype into the DC W bz. eq t!rOC converter. Aucilo trorr, the rece1 ver IS fed into the side at the equipmPnt. Have the ET' � make sure that hath SGC equipmen t. When 700 hz tone is received, the eqUip­ the m ark anl1 spocP trequencies are correct from the equip­ ment converts this to a teletype mark; when hz tone ment and the AN/SGC- will praVI

operated. Th1 s is the I a s1 tuatwn for 11 netted" Pal operation. This article corrects the send level The equipment has three bus1 c inputs/outpu ts other adj ustment of the AN/SGC-1 or CV-2460/SGC than the power corrnectwn. A t eletype naturally AN/ SRC-20( mochrne for proper input to the ) must be connected to the DC portion the rnochrne. There at communication eauipment . is an audio inprn tor the output at the recer ver to feed Tests conducted at NAVELEXSYSENGCEN tones into theSGC eq 1Jipment. There Is al so an audiO out­ Portsmo uth , VA using various send line put for the SGC to furnish tone modulatiOn to o transmllter. levels for mo dulation of Standard Navy (AN/SRC-20( ) L� F The equipment rs very si mple to use, except two equipment Family) disclosed tor points. The trrst po 1nt 1s the adjustment recP1 ver the following : at thP -10 DBM that 1s used to rec i v the radro trequency stgnols l. Send line levels of e e tram another shrp. the output a the recetver rs when produced rated modulation wi th minimum It t no1 sy, no actual srqnal 1 s bem'] recer veci, the norse wrll tnqger harmonic content measured in percent dis­ tortion on correctly adj usted eauipment the SGC equipmen t into a RCVE condrton and th e equip­ (see NAVELEX manuals 0967-438-9010 and ment will no t OIJtamatically go to the TRANS when the local 0967-439-0050) . teletype keyword 1 s operated. The output of the recer ver 2. Send line levels above -10 DBM must be squelched ali to a vPry low level durinq the lime produced excessive distortion . no si gnal is being received. This level should be rn the 3. NAVTELCOM INSTR . C2300.19, neightorhoodol or -30 bm. Su ft,cient OIJuJO �uin on II d Chapter 4, of June 1975, page 48(c) and the receiver output should be av01lahle that the rece1 ved so page 5l (e) specifies 0 DBM send level tones can leave the rece1 ver at appru;:,rnately 0 dhrn. D:J setting which produces harmonic distortion not let no r se tram the recer ver trrgqer the SGC r ntu o of 23% wh ich is unacceptable. RECEIVE conr11 1ion when no tones ore bemg rece1 ved. The In view of the foregoing , the correct second point 1 s based on the rnod,rlatian level th ul h0s been send line leve l for best communications is set on the ship. all ra r ophon remotes are set to tur­ -10 DBM . If d e (EIB 946) i sh - mto the sppe,:h ampllliers the tron smrtters n 10 dbm at and the Output ot the SGC equipment IS Set lO urnis dbrr, f h Q to the transrn,tter, o ver mad1Jlation will occur anci thrs will brmg aoout teletype d1stort1on. the modulatron tor Ir system radiophone remo tPs set, for exornp!e, at plus has been 10 dbm, and the outp11t of u nr t s set tor dbm, the SGC 1 0 unner

AN/SGC-1 :6 ORIGINAL � ......

COMMUNICATIONS NAVSEA 0967-LP-000-001 0 SERVICE NOTES

ANTENNA GROUP AN/SRA-3

Antenna Group AN/SRA-3 is pres­ ently being used as the antenna for Radio Set AN/VRC-8, -9 , -10 , -16 , -17 , and -18 where permanently in­ stalled aboard ship. When used with these equipments, Antenna Couplet CU-226/SR , a com­ ponent of the AN/SRA- 3, is not required and should not be installed. The couplet shall be turned over to the electronics officer for dis­ posal .

ORIGINAL AN/SRA-3:1 ...... - - ,- , ,- ,

COMMUNICATIONS NAVSEA 0967-LP-000-0010 SERVICE NOTES

AN/SRA-9, -12 Modified Installation Method

It has been suggested that the method of mounting Electrical Assem­ blies AN /SRA-9 and AN/SRA-12 be modified so that ac cess to the rear of the uni t can be gained for chang­ ing filter subassemblies without dismount ing the whole un it . This can be ac complished by securing the right-hand end of the panel , by means of a piano hinge , to the standard 19-inch rack or other foundation. The left -hand end of . ! the panel is secured by the usual i 1. · j No . 10-32 screws . Normally , the proper filter sub­ as semb lies to cover the ship 's regularly operating channels are installed at the shipyard and it is seldom necessary for ship 's forc e to change these subass emblies . For thi s reason , a general field change to modify the mount ing of this equipment is not just ified . The method indi cated in the suggestion is satisfactory , but its use will

I be left to the discretion of the I installing activity . I I I

ORIGINAL AN/SRA-9: 1 / ...... - .. - .. -

SERVICE MOTES NAVSEA 0967-LP-000-001 0 COMMUNICATIONS

ELECTRICAL FILTER .ASSEMBLY .AH/SR.A-12, 12.A, EQUIPMEH T .AFFECTED

Reception when using the A� /SRA-12 may be improved by proper internal connection and proper operation of the receivers connected to the filter as.sembly. The following adjustments and connections should be checked: a. Using AN/SRR-11, 12, or 13 receivers, the links in the antenna circuit should be connected for parallel operatJOn and low impedance. b. The antenna compensator controls on the front panel of all recei ver s should be rotated a full 360 in deter­ mining the position of maximum signal. In the AN/SRR-11 th is rotation actuates a switch which adds a fixed capaci­ tor over 180 of the rotation . c. For maximum signal, only the red circled jacks at the bottom of each row should be used. The other jacks, wh ich are connected to the filters through decoupling resistors, should be used only if more than one received frequency is within the pass band indicated above the row, or for very strong signals.

ORIGINAL .AH/SRA-1 2: 1 . I ' ...... · .. .

..- .. - ..- ...

COMMUNICATIONS SE RV ICE HO TES · ! NAVSEA 0967-LP-000-0010 AH/SRA-13 THRU 16-ANT ENNA COUPLERS INCREASED POWER LEVELS AND IMPROVE D OPERATING PERFORMANCE

An equipment modification has been developed to permit operation of the AN/SRA-13 through 16 with hiqh powered tran smitters similar to the AN!URT-23. The plans for th is modification have been distributed to Naval Shipyards. A formal field change bulletin wi ll be distributed in the future. This equipment modification for 1 KW (RMS) operation will: a. Reduce the elevated operating temperatures and resonant frequency drift which would be experienced at the I KW (RMS) power level. b. Provide proper control of operating perform­ ance by means of proper alignment, inclusion of impedance compen sation circuitry, and close control of input impedance. c. Provide improved voltage flashover capability at the 2 KW (PEP) level. d. Eliminate troublesome sources of RF noise that exists in unmodified equipments. I Details of this equipmen t change are provided in Puget Sound Naval Shipyard drawings 409273MC! through ·j 409273MC6. These drawings may be used pending avail­ ability of the formal field change. Due to the complexity, installation of th is change by a oval Shipyard is reccommended. (E!B 73 1)

I I I

ORIGINAL AH/SRA-13 TH RU 16:1 ...... ,- ,- ,- ,-

COMMUHICA TIOHS NAVSEA 0967-LP-000-0010 SERVICE NOTES

VOLTAGE BREAKDOWN REDUCTION in .ANTEHH.A TUNER COUPLER.AN/SRA-1 8

destroyers types, two Antenna Tuner Couplers On DDR AN/,SRA-18 are located on the TACAN l!XlSt, just aft of number one stack, where soot collects very rapidly. Life expectancy under these conditions has been about three weeks. It has been recommended by the USS WILUAM M WOOD (DDR714) that the installation of the tunner/coupler units be installed so that the terminals of the unit face aft instead of forward. Since a number of instances of voltage breakdown troubles, caused by soot accumulation, have occurred with these units, the Bureau of Ships coocurs with this recommendation in order to reduce voltage breakdown .

AN/SRA- 18 , TN-342/WRT-2 and TN-345/WRT-1 Antenna Tuners--Improved Method of Seal­ inq Feed through Insulator (IL-59/UR)

The foll owing improved method was received from Boston Naval Shipyard ,

Mo st IL-59/UR feedthrough insulators are subject to leakage around the feedthrough bolt and cap when used on pressurized unit s, This leakage can be stopped by using the following method:

1, Disassemble the insulator, 2, Clean all metal surface�. 3 . Clean the top surface of the teflon insul�tion material . 4. Apply a 1/16 inch layer of Silicone Rubber (RTV-731) FSN 9Z5330-842-6380 to the inside of the insulator cap . 5. Reassemble - the insulator and tighten until a solid bead of RTV is forced out around the insulator cap. Let stand for hours, 6, 24 7. Retighten insulator assemb ly until a good seal is assured to compensate for shrinkage of the RTV and then reinstall the insulator in thP tuner . (so 1)

ORIGINAL AtVSRA-18: 1 ......

COMMUNICAT IONS NAVSEA 0967-LP-000-0010 SERVICE NOTES

Antenna Tu ning Group AN/SRA-20 Rol ler Modification

The following information was submitted by Mobile Electronics Technical Unit Eleven : "(a) When tuning chaMels l through 4, selector A allows four circuit to be operated from a single auto-trans­ former T-101, matching the antenna on four pre-set channels. The rollers, used to tune T-101 on channels 1 through 4, slide on fixed shafts and the clearance between roller and the shaft appears to be excessive. As a result, the rollers which do not make contact with the auto-transformer during the tuning of channels l through 4, will shift due to ship­ board vibration and when a pre-set channel is again selected there is no assurance that it will remain tuned. A mismatch can result. Operation of Control B also resulted in unused roller movement. (b) S- lOlC Channel selector C acted much as did Chan­ nel selector A. This problem was more pronounced in posi­ tions 1 and 2 which affected L-101 and L-102 and was more critical than the situation described above. The rollers may be stablized on the stationary shafts by the addition of 11 a spring loaded contact as illustrated in Figure 1. It is recommended that ships experiencing difficulty with the AN/SRA-20 coil rollers in the R F tuner unit, modify these rollers as described.

1116" HOLE !AI

SPRING WIRE (C)

Soot'!twl,. (c) lo I" ol Gt511S.I9J.IHO """" - EMo 318" -90 toAtloto looloo(o) _.�� _l ______

1/16" HOLE (8)

FIGURE I

ORIGINAL AN/SRA-20 : 1 ...... ,.

COMMUNICATIONS NAVSEA 0967-LP-000-0010 SERVICE NOTES

Antenna Coupler Group AN/SRA-22 AN/SRA-22-TUNING INFORMATION

Performance and Operational Reports received indicate In order to assure proper tuning of the AN/SRA-22 equip­ several equipment failures that have been attributed to ment and to eliminate equipment failure, the following improper operation or installations. points should be understood: It is important to tune the AN/SRA-22 with oolyTUNE l. Do not operate the AN/URC-32 at output powers of power applied from the associated Radio Set AN/URC-32 over 500 watts. (tune switch is located on the power amplifier chassis), 2. Always use "Tune" power of the AN/URC-32 when otherwise a badly detuned antenna can cause damage to tuning the AN/SRA-22. the coupler unit if full power is applied. Additiooally, the 3. When tuning the AN/SRA-22 to any new or change of AN/SRA-22 antenna coupler control unit contains a SERIES­ frequency, always start the tuning procedure with: SHUNT and CAPACITOR switch that must be operated in a. Capacitor series/shunt switch on "Shunt 1 1 accordance with the instructionsin the technical manual b. Capacitor switch on "Position 1 (or on the associated Operating Instructions Chart). Steps c. Coil and tap dials on "10011 should be followed in that definite discreet sequence and d. Coil and tap meter on "0" this switch should not be moved again until the red light e. Capacitor-indicator light (red) "Out" on the panel indicates the variable capacitor of the coupler 4. Do not rely on fixed precalibrated capacitor, coil, or has stopped moving as indicated by the red light being tap settings issued by any activity unless these settings ex tin gui shed. have proven to be satisfactory by actually checking the On certain frequenci es and when working into a whip settings, by tuning the AN/SRA-22 in accordance with the antenna, if the switch is moved more than one step at a existing procedures in NAVSHIPS 93286 change 2, or time, a radical large change in 0 is possible so that excep­ NAVSHIPS 93286.2l(A). (Note: These publications are tionally high voltages can develop within the coupler to now available in Navy issuing activities and they should be cau se a voltage breakdown . requisitioned as soon as possible.) The impedances of 35- Addi tiona! difficulties reported indicate that improper foot whip antennas on board ships are not necessarily the antenna tuning is caused by a dirty antenna base insulator, same because impedance depends on many factors; thus the leaky coaxial cable transmission line to the coupler, or AN/SRA-22 settings of capacitor, coil, and tap will not be inadequate coupler unit grounding. Periodic inspection and the same for all ships or even for the same class of ships. cleaning of the antenna base insulator "megger" checks of It is best to calibrate each antenna and AN/SRA-22 using the tran smissim line, and verification of a good groun d the information (Procedures) in the above mentioned publica­ connection to the Coupler CU-7 14/SRA-22 case will reduce tions and not to take for granted the AN/SRA-22 settings (561) these failures. Do not rely on a good ground being pro­ that were taken on other ships. vided by the bolts attaching the coupler to its mounting ; a separate groun d strap is mandatory. (532) AN/SRA-22-INSTALLA TION

In cases where installation requirements dictate the AN/SRA-22 ANTENNA COUPLER -BUREAU OF SHIPS need for a right-angle multiconductor plug, in lieu of the PLAN DISCREPANCY supplied straight type (PS), the following plug may be re­ quisitioned and installed: BUSHIPS plan RE47C20l3, recently issued, contained .I an inadvertent wiring error. Installations of Antenna Coupler AN/SRA-22, using this drawing for cabling infor­ Type FSN mation, has resulted in a damaged tuner unit. AN3 1 06A-34-285(s) N5935·1 95-8049 BUSHIPS plan RE47C2013 has been superseded by plan Connector I AN3057-16 N 5935-283-3402 RE4702021A. This plan and the AN/SRA-22 Technical Clamp Manual (NAVSHIPS 93286) are correct and shall be used. (516) Theconnector sleeve supplied with the equipments plug (PS) may be removed and used on the right-angle type con­ nector. (560)

ORIGINAL AN/SRA-22: 1 ...... - ... - ... - ...-

COMMUNICATIONS NAVSEA 0967-LP-000-0010 SERVICE NOTES

AH/SRA-22; PREMATURE TRIGGERING OF VSWR Reeommendotions: PROTECTIVE CIRCUIT Coil Stop Assembly MP-129 (Index 282): To reduce the possib-ility of a casualty associated with the coil stop Investigation of reports concerning the triggering of the assembly, operating personnel should use caution when VSWR protective circuit (furnish�d in later production models carrying out steps 4, 5, and 6, the COIL COARSE TUNE/ of the AN/SRA-22 or installed as a field change) by as FINE TUNE switch should be so used that the operator will little as 4 watts of reflected power has indicated that the minimize a tendency to overshoot when br inging the COIL possible cause is a poor ground system established at the meter to zero (needle center of scale). Using the COIL time of installation of the AN/SRA-22 equipment. COARSE/FINE TUNE switches in the FINE TUNE position Ships and activities are again cautioned to ensure a good will aid in preventing the possibility of overshooting. metal-fa-metal contact in the go unding of the CU-714/SRA- If the coil switch is operated much beyond that speci� 22 coupler unit. rely on the equipme nt mounting lied ln steps 4, 5, and 6, as will be indicated to the oper­ Do not bolts ; use a grounding strap. Additionally, be sure that ator by the COIL meter swinging to the right of zero (needle the cable used in the antenna transmission line system are to right of center). the coil will come up against the coil good. stop assembly. Repeated banging of the coil against the coil stop assembly has been responsible for the weakening of the coil stop assembly, which, on failure, can cause AH/SRA-22 BLOWER MOTOR antenna coupler damage and a resultant CASREPT. Further, repeated or extended operation of the COIL Failure information, reviewed by the Electronics Main­ COARSE TUNE/FINE TUNE swi tches (which causes the tenance Center, has indicated certain component fa ilures coupler to bang or remain for extended periods against the in CU-714/SRA-22 coupler are caused by high temperatures coil stop assembly) can cause motor failures. within its cabinet. One such report, submitted by USS Potentiometer Alinement: Whenever any repairs or re­ TANNER (AGS-15). stated that blower motor (8-l) in Con­ placement of parts are made to the CU-714/SRA-22 tuning trol Coupler C-2698/SRA did not run , thus causing the fail­ assembly, the potentiometer alinement (see NA VSHIPS ure of CU-714/SRA-22 components because of high cabinet 93286, including Change No. 3, page 5-15) should be re­ temperature. It was determined that the blower had failed checked to insure that the COIL and TAP dials will provide to function because of transmit-receiverelay contact failure. proper indications of the coil and tap positions. If a recheck 11 11 2 of the potentiometer alinement is not made, neither the COIL Relay contacts in section 0 , K-1 , located in ANIURC-3 Sideband Generator had burned open. andTAP meters nor the COIL and TAP dials will be use- The Electronics Maintenance Center is investigating the ful in carrying out the proper tuning p-ocedureof the Oper­ failure ofthe transmit-receive relay contacts and will pro­ ator's Instruction Chart (NAVSHIPS 93286 . 218). vide corrective action. In the interim, it is recommended NOTE that section 11 11 K-1 . transmit-receive relay contacts be Correct spelling paragraph 5-6c(8) of HAY­ 0 , of inspected frequently to ensure that good contact closure is SHIPS 93 286 (including Change Ho. 3) , page occ:uring. Contact closure may be checked by connecting 5-16, to read, "RUH THE TA P. " an a. c. voltmeter between terminals and 13, terminal board Replacement of Coil Stop A:ssembly: New production mo­ I H located in junction box (J-1 007) in the AN/URC-32. The dels of the AN/SRA-22 are being provided with an improved voltmeter will read 115/120 volts (when the transmitter is Coil Stop Assembly MP-129 (Index 282) of heavier gauge (21 gauge, 0. 0285) spring material. units that are being keyed ) if the relay contacts are closing properly. On repaired at the AN/SRA-22 repair facilities, this new coil slop assembly is being installed during repair. AH/SRA-22 AHTEHHA COUPLER-SUPPLEMENTARY IN­ Replacement Procedure: STRUCTIONS FOR ALIHEMEHT OF COI L STOP ASSEMBLY a. Remove CU-714/SRA-22 tuning assembly from water­ MP-129 tight case. b. Refer to AN/SRA-22 technical man ual, figure 5-5, The advisability of further amplifying the instructions page 5-19 (exploded view of CU-714/,SRA-22 tuning assembly). relative to STOP and POTENTIOMETER alinements after c. Manually roll ribbon and coil tap to about midpoint repair of Coil Stop Assembly MP-129, index 282, stems from of High Voltage Drum. recent comments received from the fleet. The following d. Mark position of Low Voltage Drum (Index 107). supplementary instructions and suggestions should help Low Voltage Drum End Assembly (Index 120). and the Low clarify and resolve some of the problems experienced after Voltage Drum Driven Gear (Index 102). This marking is for repairs as well as reduce repeated failures of these equip­ reference alinement during reassembly. ments. e. Remove four screws (index 104). Remove roll pins (index 100) from either side of gear References: fl AN/SRA-22 Operator's Instruction Chart, NAVSHIPS 102. 93286. 21(8) g. Remove switch (index 78) from shaft and push to one AN/SRA-22 Technical Manual, NAVSHIPS 93286, side; this will permit removal of gear 102. including CHANGE 3 h. Push end assembly (index 120) against spring into Low Voltage Drum. i. Remove gear 1 02

ORIGINAL AN/SRA-22 :2 ...... ,. ,.

COMMUNICATIONS NAVSEA 0967-LP-000-0010 SERVICE NOTES

j. Mark position of Coil Stop Assembly (index 282) on applies to theentire antenna cou pler unit, includinq the fiber plate face (index 419) so that a new coil stop assembly case and blower. See figure 101 of the NAVSHIPS 0%7- can be inserted in the some position as the one that was 1.36-6010 the technical manual for AN/SRA-n. removed. Remove set screws (index 260) for Coil Stop When shippinq for repair, assure that the entire unit is (index 261 ) . Remove damaged Coil Stop Assembly (index sent. Additionally, when shippinq the CU-714/SRA-22, 282). Install a new stop assembly and reverse the above the shipping lobelinq should include the unit stock number procedure for re-assembly. (FSN-F5984-789-1987) for stock identification. If the CU- (61 9) 714/SRA-22 and the control C-2698/SRA-22 are turned k. Recheck potentiometer olinement. unit in, the appropriate stock number is then FSN F5985-543- AHTEHHA COU PLER GROUP AH/SRA/22-AHD USE 186l. Pack adequately to insure further damaqe ITS oqainst WITH SUBMARINE EMERGE HCY WHIP AHTEHHA caused by shippinq. u-n4!UR Ovemoul Instru ctions Manual Chanqe to th is manual (NAVSHIPS 93286.61) is now I The U. S. Navy lec ronics Laboratory , Son Dieqo, has available and if not received, should requisitioned. This E t be recently completed testsand measurements on Antenna manual is normally held by shipyards, repair activities, Coupler Group AN/SRA-22 ond its use with the submarine METU 's, and tenders . This chanqe provides additional emergency whip antenna AT-774/UR. Results of these repair instructions, disassembly-assembly information, and tests show that the equipment provides satisfactory per­ Alignment details. formance over the entire frequency range from 2.0 to 25 me. Erratic Tuning . i The e f ienc of the c upler was approximately 40 percent When experiencinq erratic tuninq, particularly in the 2- ! f ic y o 2 to 4 me., 60 to 80 percent from 4 to 8 me., and 80 to to S-mc ronqe, checks should be mode for a POOr or lost 90 percent above me. No dilficulty was experienced when around connection on the CU-714/SRA-22 unit. A GOOD 8 operating with full power (500 watts) at any frequency qround connection MUST be mode to this unit. 00 NOT tested. RELY ON THE EQUIPMENTS. MOUNTING' LAG SOL TS; provide a qood qround strop and clean metal-to-metal con­ RIBBOH BREAKAGE IH AH/SRA-22 nections. A faulty C7 vacuum capacitor will also cause erratic When the coil-ribbon breaks on the AN/SRA-22, it often tuning. breaks on inch or two from the end which is attached to CU-714/SRA-22 Tuning Slug (H7) the metal drum . It has been reported that emergency repairs If failure of the tuninq sluq is experienced and repairs hove been mode by shortening the ribbon by the amount cannot be immediately made. the ANISRA-22 con bP still that was broken off. This practice is not approved and will used at frequencies above 3 me. Normally, the sluo is onlv necessary at the lower frequencies, For emerqencv be discontinued, because it chonqes the end-stop settinqs this and causes further damage to the unit. If a new ribbon measure, use caution in tuninq and follow th e tuninq proce­ is not avai !able, the two ends are to be silver-soldered and dure steps. the ribbonreplaced with a new one as soon as it is Operator's Tuning Chart The design of the AN/SRA-22 prima l for use with available. is ri y a standard 35-foot whip and the Operators Instruction 010rt (NAVSHIPS 93286.21 (A). supplied t e equipment) pro­ CU-714/SRA-22 FAILURES IH AH/SRA-22 with h vides for tuning this type of antenna. When tuninq other investiqation of P and failure reports concerninq types of antennas, refer to the equipment technical manual. An 0 this unit indicates that a majority of the failures hove been When tuning antennas shorter than 35 feet, the procedures caused by miswirinq of plug P-7 upon n a lation. Costly are the same except when tuning frequencies in the 2- to i st l compon ents ore damoqed beyond repair because of neq]j­ 3.5-mc ran ge. For this type of antenna, a new step (So .) I g should be added after the "NOTE" in step of tuninq ence, not verifying proper connection , wirinq continuity, S, . I checks for solder shorts, and th e proper &ealing aqoinst salt chart as follows: Tuninq step lor antennas shorter than 35 feet in water penetration of the completed plug after assembly. "5. the range. !f no dip is found, leave the COIL and I These units ore in critically short supply because of funding 2to 3.5mc ati ns permi t e procurement of one AN/SRA-22 TAP where they ore (i.e., the COIL should at and the I limi t o which th be SOO for each AN/URC-32. When a replacement unit is requested, TAP at 100). Advance th e CAPACITOR position switch its issue jeopardizes other ship installations unti l repair one position at a time (woitinq until therun liqht qoes ou t of the foiled unit and return to stock con be effected . between each step) while watchinq the reflected power for Several ships have remoted the antenna tuninq-ossembly a dip. CAUTION DO NOT switch the capacitor SERIES/ section from the case and have forwarded only this unit to SHUNT at all times when this step is used. " Chonoe the NOTE in Step 5 to read "proceed to STEP a repair oct1 ty . prCJctJce has caused additional Sa ." vi This C damage and further equipment shortages. -2698/SRA-22 Control Unit Although the block unit-nomenclature plate is o(lttocted to Assure the installation of a l-1/2 ampere fostblow (JAG) the tuning unit section, the nomenclature CU-714/SRA-22 type fuse at Fl. Replace fuse if other than this type is in­ stalled. The lN 1084 diodes and the helipots will not take

ORIGINAL AH/SRA-22: 3 ...... - ..-

SERVICE NOTES COMMU �'ICATIO�S NAVSEA 0967-LP-000-0010

s l thct the c t r of cct! a:ound and th rouqh the po s i b ;, 3UO-pc::cent ove·:iocJ ·c slow-blov; allows . en e (lLl) sluq (lH7). to ,�ouble · tf-�e cc:.:c. air cooleD by natu­ Stock nur:,bers. Fer in!ormotio�. the stock numbers for lhe -..-:ell c ! T.�e is then c n 1terns are: ral ra at n from thecase. (672) re urri g fc. lu:e di io c:r.d con•Jectior: lD Cc!l r;b[jc; 9Z9S4:r649-7tl22 9 0 81 7 AN/SRA-22 ANTENNA COUPLER -GROUP SEALING OF lH7 C:.;; l core 9N 5 5 -6 -b8 0 1 9NS950-583-0924 SETSCREW WITH GLY PTAL OR VARNISH Ll Cn; ! ior;';"; 116 N-5820-b7 1-l311 1M :oiler or Water in Antenna Coup I er F oilure to secure setscrev.s by appl·yinq q]yptGI water the case of t ar tenno c p r varnish on th<' :.r. rca�3 fai l re�: cf th" Atl/SRA-22 Per,etrotio:; oi ir.to h e ou l e is cuus1r. ; u has to an '] Osket the Antenna Coupler. Drive motors, stiches, and 1ears been utlrtlJtltt"'·: · i::��iope�l·t' !esiqned !n · ';erial numbers r are oni · _ (:i<:::Pnqa:wd frc:n tt"--_elr shafts durinq emits w ith l through 1\95. The Con tracto br�c n : recen tly st:lp;Jed replocP::.ent LJsc _-::_::l .:: f: nDt qaskets to all hol dr::s of tr.ese norrr-.cl an.·l '.·ir-ruticn.s/ �--� :i·�..:=-\'· }·_o\'e been be installed as s propedy secur-:j. (674) equipments . T0;e nev1 gaskets shou ld oon as possible onr! the ori �mol 1askf% returnee! to the contrcc­ AM/SRA-22 CONNECTOR SEALING tor. When replacinq this gasket, the use of a silicon com­ such v:i ll \\'Otertiqht pou n�l c:; L:(>4 insu::� c r� ;ore seal. p pluCJ To further mo: sture-proci RF anr:i rnulticonductor Always re lace the J-9 blower rnotor before repla­ thr cable connectors ten:;inoted at the weathH exposed cing the tur.:n•J 'Illit of the CU-7 1VSRA-22 in its case. CU-7 14/SRA-22 unit, it is recommended t these Test Cable hat A test cable is valuable asset the A N/S A-22 connc�ctors, o as a for R for cfu·�r a�-:: ;sf·mbly, be coc:tc�.-1 t.·.-i th sealant L: U-714/SRA-22 unit from n descri be in thl' Gener,Jl Mair.tcnance NAVSHIPS use when the 1:' rer.wved its mou t­ d Handbock , 0967-000-0160, (605) ing and placc·:i neo: the AN/URC-3;: fer testinq or mainte­ s('f" tion 6. ch be locally fabrica ted nance eck; . T!c�:·. cor:troi cable con :dobl;e -24 AN/SRA-22--MAIHTEHAHCE HINT w:th o plur; (l�j':.rJS-296-8'17S),u lenqth of MSC:A or s mi lar a �' ltlg (NS9 (NS935-552-7255). i cable, und ''"' l CAUTION- Wh en testing the AN /SRA-22, in sure that th e 11-t is nrtic e •iescribes the method to be used, and the output bowl insulator is terminated in a suitable load, such material requ i rc.-i , !or improved l':eotherproofing of as shown on BUSHIPS pion RE 21458, or damage will Antc:nno Coupler CU-7HlSRA-22. 66C re sult. MATERIAL REQUIRED: CHECK-OUT PROCEDURE FOR AN/SRA-22 ANTENNA COU PLER Item DescriPtion Stock No. In:s1dution tc 5970-!BB-� l W[X·, m 2 Electrical insu!Gtinq I'IS970-29S-83S7 See CJrtick i� section under some :itie. M·l/\JRl-32 tl:c· r:ou:;;pounrl 97�·330- 36 1! AN/SRA-22 ANTENNA COU PLER GROU P-MAINTENANCE 3 101 ring stock 1 87- 4 Brass 9C4730-254-b242 HINT 11'1 stock j S970-l �:9-1 '>98 l';tock tCJ The pu q;::.:f.' C' f t� is orticle i� ud'.:i:::::e rnuin ten ance 6 stoc� per,�onnel at :::c: j.lr cause to lLl :s due fWT-lU2 th thr:: of damcqe coi l Goskt:t, r\Oteriol stock , to heat to 7 bei nq qenerolf'l: in .� lug lH7. Viher lLl he:: be l/8 in replocr-=-1, l �(·plu·:�erl . ·h - the i�rl · : u'J nl::;i) ::-J:c·u;;: be The slu(] iron qranu]e;; IH7 con tainc: 1n a teflon boncli na PROCEDURE: · · ' ·. i:: .:<'nerotc;cl mntr:riol. Wf11...r, '· ' " '" : i vc heat in !f·L' :t -: u:� ses te f lon bor:r!Jr:_J to 'J!lo•:: ir.:; tl ,,, the "''Jter:ui melt therel·o ::en The ce u prc d r'? to be used in -.':eatherproof:n•J cable:: ·1 �onule:-· to co::l�_: · n C(:r; t::;c� \\' ith t:-,_;.-f; c·:�v:,r ·, :reatin�l f!�crc . and in seoling the· coupler is fully illustr'Jted ir: c:(--!HWJ iiy dc��trcy�_:; th(' a heal which 1H7 siuq. Th�iC' is ligures .. u a i e lH7 sluq l un<: 2, f>':7. �ec:i· ·c.J.,- . c mul t v nonre·;ersibk x: t:on. Therefor:;, lf the not lLl, :t :. ill .!•1rli

purpo:e ic: advise ncintenance The oi thts ,:rticle to shroudo: on perc:onnel thc:t ti,c: remo·:c:l o::rl iic:cordin� of thco CU-7l4;SR/,-t2 wJii "·'''':it m f: "ceo· ..·:· ·x· ._:orr,ponF·n t h12ot:n-:]. The puq.JO:Ol: •Ji •he::hrouds :s :':. jl :,�c:t encls-se:l air throur:Jh

A /SRA-22: 4 ORIGINAL N ...... - .. - .. - .. -

COMMUHICA TIOHS NAVSEA 0967-LP-000-001 0 SERVICE NOTES

CUT ARMOR BACK

r---- 4" ---,

WRAP TA PE FROM ARMOR TO WIRES

WRAP CONNECTORS WITH TA PE (ITEM I) APPLY ELECTRICAL INSULATING COMPOUND OVER TA PE (ITEM 2)

Figure 1. Weatherproofing Cable

ORIGINAL AH/SRA-22: 5 I, 0 ;o...... n 0 "'...... � c: ::z: z: I)> n ,. -1 MAKE 0 .,.z:

I,

:z �- -: (./) - fT1 ? / / l> / / 0 / / \00'1 ...... USE INSULATING < COMPOUND (ITEM !I) I CASE , GASI

USE I ATING COMPOUND (ITEM �) ON GASKET,CASE AND COVER.

.,. m .. ;:u < Figur 2. Sealing CU-7 14/SRA-22 n e Method ol m z: 0 -1 m .,...... ,- ,- ,- -.-

CO MMUHICATION� NAVSEA 0967-LP-000-001 0 �ERVICE NO TES

CU-71 4/SRA-22 COUPLERS IMPROPER HANDLING OF

See ticle under wi th same title. ar CU-7 1 4/SRA-22:1

AN/SRA-22 ANTENNA COUPLER GROUP­ MAINTENANCE HINT TO REDUCE BREAKAGE OF RIBBON 1 E7

Maintenance personnel are advised that the placement the lve under the of si r ri hbon , 1 F:7 , the screw on metol causes the fracture eventually drum ribbon to and break . (See figure 1 ).

Figure 2. Recommended Method of Mounting Silver Ribbon IE7

AH/SRA-22 ANTENNA COU PLER GROUP-REQUISITION· INC AND TURN-IN PROCEDURES

The av l Division, N a Sh 1p E:rqineerinq Center, Norfolk has received reports statirq thm the wrong stock number i s used when requisitioning (FSN F5985·S.:l3-1861) beiw; units of Antenna Couplc'r Group AN/SRA-22. When re4uisi tioning units of Antenna Coupler Group AN/SRA-22 (F5985-543-1 861) (in accordance with NAVSHIPS Instruction 967 1 .228), the followmr1 applies.

UNIT FSN CU-714/SRA-22 F5985-789-1987 C-2698/SRA-22 F5820-897-5501

Figure 1. Present Method of Mounting Silver Ribbon 1E7. Repair facilities report that Antenna Coupler CU-714/SRA-22 is being received in a damaged condition lt is recommended that the ribbon not be secured under by having shipped i t u case. been w ho t ;ts th e sc , bu t that nn turn of ribbon be token on Activities are ad vi s rew crddltlonal ed that shipping the CU-7 1 4/SRA-22 th� ond cause drurr.. Th i�; wili re··:�.lct.:. ni·hc::i : ·reokJ·le the without the case has resulted in damage to the lC7 vacuum ribbon to run strai']hton the drum. (See figure 2). (701) capacitor anrl other replace vacuum ports. 11-r e cost to JC7 capacitor is approximately $219.00 and cost of replacement rn issinq of the cm;e is $495.00. Therefore, in order to eliminate these unnecessary costly replacements, e which hove s i p thos activities h p ed Antenna Couplers repair faci lities their sh I CU-7 1 4/SRA-22 to wi thout cases ould ship the to repair facilities ccse!': the respective i the earliest practicable at dote. In addition, activi ties are advised that no further ·I shipments of the CU-7 1 4/SRA-72 :;hall he made without the case. (E lB 712)

AH/SRA-22: 7 ORIGINAL ......

.. - .. - .. - ..-

cow.lUNICA liONS NAVSEA 0967-LP-000-0010 SERVI CE NOTES

INSTRUCTIONS FO R TH E RETURN OF AN/SRA-22 AN D 7. List ofAut horized Repair Facilities: ITS COMPON ENTS FOR EXCHANGE AN D REPAIR Norfolk Naval Shipyard, Portsmouth, Va. Franci sco Bay Naval Shipyard, San San The AN/SRA-2 2 (225985-543-1861 ), which mnsists Francism, Calif. 1. of Antenna Coupler CU-714/SRA-22 (2 25985-789-1987), and U.S. Naval Ship Repai r Facility, Guam, Control Unit G-2698/SRA-22 (225820-897-5:01), as a whole M.I. or part, are subject to automatic return for exchange and U.S. Naval Ship Repair Facility, Yokosuka, repair when found be inoperative. to Japan 2. order to shorten the paper work and material pipe­ In U.S. Naval Ship Repair Facility , Subic line between the Fleet and the R�air Facilities, all Bay, P.I. activities and ships are authorized to return the above ma­ 8. All of the restoration activities r�ort that requisi­ terial to the nearest of the five listed Repair Facilities for tions for replacemen ts in Ready-for-Issue condition con­ exchange. This will be done without reference to the Naval stantly exceed the quantity of Non-Ready-for-Issue materi al Electronic Sy.;tems Command Headquarters. being turned in. All ships and stations are requestedto 3. NAVEL EXINSTRUCTION 4400.2 ELEX 0522 of 26 expedite the movement of this material to the designated Re­ December 1967, which supersedes BUSHlPS INST 967 1.22 Facilities in order to minimize this condition. pair Ser62701-532 of 18 January 1965, is for all intentsand 9. The stockingactivity in WESTPAC should request pmposesidentical to the BUSHIPS INSTRUCTION, except from OOMSERVPAC of this material, if held in release that the three 'Repair Facilities in WESTPAC have been stock, and if not in stock, pass the re::j uisition to included as sources for the exchange and repair of this OOMSERVPAC for action. The remarks section of the material. passed requisition should mntain an estimate of the earli­ Brief: When the above material bemmes defec-­ est date that the requisition could filled if back-ordered 4. In be tive, it is to be returned to the nearest of the five listed from restoration assets. COMSERVP AC will then determine Repair Facilities, via the Naval Supply Depots, at material is to be back ordered or if the requisition is to if Yoko suka, Subic Bay, and Guam for ship s in WESTPAC, as passed to another activity. be expeditiously as possible. Replacements will be provided 10. The Naval Electronic Systems Command will not on a one for one basis from Ready-for-Issue stock held by action on requi sitions for this material. They will be tale the Stocking Activity. If Ready-for-I ssue stock is not referred back to the requisi tioner wi th instructions to pi ace avail abl e, the requi sitioned itemwill be placed on hack with the nearest Repai r Facil ity in com­ their requisition order, and the requisitioner will be advi sed of the estimated with NAVELEX INSTRUCTION 4400.2 of 26 De­ pliance date the replacement will be shipped. For each item re­ cenber 1967, and assure the return of the Non-RFI material turned, the ship or activity will submit a requisition for a as required. (730) replacement the stocking activi ty to which they shipped to the defective item. This requi sition must include the docu­ ment number under which the defective material was ship­ ped, and provide the name of the Supply Actvity to which it was off-looclP.d. This action will be taken wi thout reference to the Naval Electronic SystemsCommand, except that one copy of the requisition should be fo rwarded to NAVELEX Code 05222 for information. 5. To expedite the movement of this material, a MOVEMENT PRIORITY DESIGNATOR (MPD) 03 is be to on all shipments. used 6. Every mmponent is to be Poclcaglng and Pocking: thoroughly packaged and packed to prevent damage. The CU-714/SRA-22 must shipped in its pressure-proof case. be This has called to the attention of all concerned in been previous issues of the EIB. (See EIB 671 of 26 Decem ber 1935, and EIB 712 of 31 July 1967.) Both articles stress necessity for shipment of the CU-71 4/SRA-2 2 in its the pressureproof case toprevent damage to Vacuum Capacitor which is a high mst item. lC7

ORIGINAL AN/SRA-22:8 I' ...... - ... - ...-

COIJMUNICATI ONS NAVSEA 0967-LP-000-001 0 SERVICE t+OTES

OPERATION OF AN TENNA COUPLER AN/SRA-23(XH-1) tuning of transmitter and coupler for normal operation. Ad­ WITH THE AN/URT-17 TRANSMITTER just incident-power-meter calibrating potentiometer for down­ scale reading, to potentiometer stop. Antenna coupler AN/SRA-23(XN-l) is capable of handling 3. Adjust transmitter CW carrier to give 4.S-amperes of the output of transmitter AN/URT- 17 without damage. It is output current into the coupler, giving approximately 1000 necessary , however, to recalibrate the INCIDENT POWER watts into a 50-ohm load. meter in the coupler for full scale deflection with 1000 watts 4. Adjust the incident-power-meter calibrating potentio­ of RF power instead of 500 watts for which the meter was meter so that meter reads 500 watts. not touch the Do originally calibratE:d. To accomplish this, proceed as fol­ reflected-power-meter calibrating potentiometer. lows: 5. Attach a label to the incident-power-meter face indi­ 1. Connect a dummy load, DA-91/UR or equivalent, to cating "METER READING X2." This completes the recali­ the antenna terminal of the antenna coupler. (WARNING: brating procedure. dummy load rated at 500 watts without forced-air This is The above procedure is applicable to other installations cooling. When dissipating 1000 watts, apply power only in­ involving transmitters with 1000-watt output capability when termittently, IS-seconds on and 4S-seconds off.) used with antenna couplers AN/SRA-23 (XN-1). 2. Adjust the transmitter for a low-output indication on coupler incident-power-meter (about 250 watts). Complete

ORIGINAL A.H/S RA-2l(XM-l): 1 ...... ,-

COMMUNICAT IONS NAVSEA 0967-LP-000-0010 SERVICE NOTES

AN/SRA-33 Antenna Coupler Group-­ Ma i ntena nce Hi nt

The AN/SRA-33 is em automatically tuned UHF multi­ coupler to permit use of up to four AN/SRC- Xl, AN/SRC-21, or AN/GRC-27 radio sets into a common antenna. This equipment will begin deliver in September19 65. Each of the four rouplers is automatical ly tuned ta any of 19 preset frequencies per radio set, giving a total com­ bination of 76 frequencies when four radio sets are used. The minimum allowable frequency separation between 5 any two radio sets iscqJproximately megacycles. If the frequency separation between cmy two radio sets 1s less than 5 megacycles, the automatic interlock protective ci r­ cuitry may disable the rouplers to prevent damage. Therefore, operators are cautioned not to preset the frequencies between any two radio sets closer than q:Jproximately 5 megacycl es. {673)

AN/SRA-33 Mu lticoup1er Key Line-­ Protection of CU-1131 Through CU-1134/SRA-33 Cavities

The maintenance personnel are advised that damage to the AN/SRA-33 multicoupler cavities will resul t if removal Jl02 of jumper at pins G and H of is not acmmpl!shed in fudio Set Control C-3866/SRC. All AN/SRC-20/2 1 equipments installed before installation of the AN/SRA-3 3 multiroupler required pins G andH to be jumpered at Jl02 of Radio Set Control C-3866/ SRC in order to key the transmitter. Ji02, If there isno jumper on pins G and H of there K207, S20l, exists a possibility of a jumper at pin I, and terminal 8, of C-3866. In eJther case, the jumper should be removed so that the AN/SRA-33 will open assoc1at ed key lines to the same channel , thus preventing any AN/SRC-20/ 21 installed in the same bank of mul ticoupler from keying

into an unloooed cavi ty. (EIB 714)

AN/SRA-33 Antenna Coupler, NAVSHIPS 0967-037- 8002-lnformation Concerning

This article no tifies manual holders that Change 2 to AN/SRA-33 Antenna Coupler , NAVSHIPS 0967-037-8002 , dated 1 July 1976 is applicable only to DD-963 class ships installations . This change is not to be inserted in AN/SRA-33 Technical Manuals for any other ship .

(EIB 953 )

ORIGINAL AN/SRA-33 :1 ...... - ...- ...-

COMMUNICAT IONS NAVSEA 0967-LP-000-001 0 SERVICE NOTES

AN/SRA-34(V) Stil etto--Ma i ntenance Remove stiletto from ma trix, place 1. Hi nt the rod in the re taining groove, and roll wi th the palm of the hand until it is This article provides a drawing for a straight. stiletto maintenance jig (figure 1) that can 2. Reinsert the stiletto in matrix. easily be fa bricated out of aluminum stock by any machine shop and is utilized for straightening the stilettoes used in the SA-1070/SRA-34A(V) matrix for crosspoint patching. To use the jig:

14------13"·-----......

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L ------J ""1"'L!--1------15':...' ______..

TOP VIEW END VIEW Figure 1. Stiletto Maintenance Jig

(EIB 902 )

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ORIGINAL AN/SRA -34(V) : 1 ...... - ,- ,. ...-

COMMU NICATIONS NAVSEA 0967-LP-000-001 0 SERVICE NOTES

AN/SRA-51 Antenna Group-Maintenance Hints

Fleet comments received by NAVSECNORDIV indicate several minor problems related to sealing of the CU-1691/SRA-51 cabinet. Some .. i reports involve seizing of the captive hold­ down door bolts and others no te an occasional gas leak through the antenna feedthru termi­ nal . The captive door bolts are an insidious problem because if one seizes , the only so­ lution is to cut off the head close to the front sur face . Such drastic action mars the door finish , but is the only means to gain access to and apply penetrating oil to the threads . In order to reduce or prevent this problem , it is re commended tha t a 1/4 inch squeeze of silicone grease (DC-4 , DC-5 , DC- 33 etc) be inserted into the bolt ho les (44) and worked into the threads wi th a ma tch stem or toothpick. Apply some grease to each bolt 's threads also . Ch eck the door (s ) gas­ ket for suff icient grease ; wipe clean if foreign matter has adhered, and apply fresh silicone grease. Replace doors , tighten bolts and charge 1 to 2 psig of dry ni trogen wi th a ��- 260/U ni trogen bottle kit. NOTE : The �- 260/U (FSN 4G5820-313-7703) is on the COSAL of all ships employing dry nitrogen filled lines , tuners , couplers , coaxial cable or waveguide . Ref ill �- 260/U at fa­ cilities such as Naval Stations and Naval Air Stations . NAVSECNORDIV has a supp ly of improved re­ placement neoprene inserts for the lAlEl an­ tenna insulator and will supply replacements upon request . The inser t is difficult to in­ stall and is not recommended for rou tine in­ stallation. Since the ins talla tion of the antenna support cone Field Change 2-AN/SRA-51, the original insert is performing much better. �equests for insert kits may be directed to Officer in Charge , NAVSECNORD IV (Code 6621£) , Naval Station , Norfolk , VA 23511. 11://J 8)5i

AN!SRA-51:1 ORIGINAL ......

COMMUNICATI ONS NAVSEA 0967 -LP-000-00 10 SERVICE NOTES

·i AN/SRA-56, -57, -58 Antenna Coupler �roup - operate with Field Change 1 but in a slightly degraded fashion .) �� en the Maintenance Hint equipment is modified p e r technical manual Change 1, this fact should also be no ted The pu rpose of this article is to ad­ in Figures 5-27 and 5-50 . vise maintenance personnel of a problem The modification of the power attenu­ that may exist when r�turning a coupler ator is not being subjected to configura­ drawer to the cabinet . tion control procedures but its instal la­ Should the output coupl1ng 1. tion should be local lv noted . assembly get pushed al l the way in acci­ An EIB art icle will announce the dentally when a drawer is pulled out or availability of the final low power tune removed from the cabinet , it will be ex­ field change kit when it is received in tensively damaged when the drawer is re­ the supply system. Th ese kits wi ll be turned to the cabinet . Therefore , before available in 12 to 18 months . returning a drawer to the cabinet make certain the ou tput coupling assemb ly is (EIB 950) in the fully extended position. 2. Using a tape embossing tool make a label stating : "DO NOT PUS H DRAWER INTO CABINET UNLES S OUTPUT COUPLING ASSEMBLY IS IN THE FULLY EX­ TENDED POSITION ." Stick the label on the top of each drawer below the present warn­ ing label .

i. (EIB 935)

AN/SRA-56. AN/SRA-57. AN/SRA-58 Antenna Coupler Groups Low Power Tune Capabi lity-Temrorary Provision for

Th is article provides an interim me thod of modifying the AN/SRA-56 , - 5 7 and -58 An tenna Coupler Groups to provide a low power tune capability until a final field change can be made available for the subj ect equipments. Field Ch ange 1 to the AN / SRA-56 , -57 and -58 provides a low power tune modification for these eq u i pment s. How­ ever , the supply of these field changes has been exhausted. Until additional qua ntitites of Field Change 1 are available, antenna coupler groups which must operate with low output power transmitters (less than 500 W, such as AN/ URT- 24) can be modified in ac cordance with paragraph 4.3.3.2 of Change 1 (NAVSHIPS 096 7-284- 6011) to the Technical Manual, NAVSHIPS 0967-284-6010. The shorting bar shown in Figure 4-3 is a six inch leng th of copper tubing of seven-eighths inch diameter mounted in the receptacles wh ich normal ly hold resistor R- 5. Eve ry effort should be made to re�ain removed resistors R- 5 and R-8 so they may be reinstalled during installation of Field Change 1, when it becomes available . (If resistors R-5 and K- 8 are misplaced , the equipmen t wi ll still

ORIGINAL AN/SRA-56,-57,-58:1 ...... � � � �

·i

COMMUHICA TIOHS NAVSEA 0967-LP-000-0010 SERVICE NOTES

AN/SRA-60(V) Antenna Coupler Group-Maintenance Hint

Th is article provides maintenance per­ sonnel with a method of repairing the slip clutch and gear assemb ly in the CU-1791/ I SRA-60(V) should it become galled to the -I shaft.

1. Remove the CU-1791/SRA-60 (V) drawer from the cabinet and remove the capacitor drive assembly as described in paragraph 5. 4. 1. 5, step 1, 3-5 of Technical Manual NAVELEX 0967-421-4010. 2. Remove the drive pin from the coun ter drive gear and remove the gear from the shaft. 3. Remove the front cover from the capaci tor drive assembly . Do not disturb the setting of the gears . 4. Mark the gears for realignment purposes before removing the damaged slip clutch and gear assemb ly . 5. The slip clutch and gear may now b.e removed and disassembled as shown in figure 1 on page 5.

6. Use crocus cloth to polish the dama ged portion of the shaft and gear to a smooth finish. 7. Lub ri cate the portion of the shaft that the gear rides on with a dry lubricant (FSN 9150- 754-0064) . Use a cotton swab and be careful to keep the plastic discs free of lubricant. 8. Re assemble the unit reve rs ing the removal pro cedure . 9. Adj ust the slip clutches using the procedures described in paragraph 5.3.10 of I Techni cal Manual NAVELEX 0967-421-4010. 'l I El ll 8<1 3! j I I I I .!

/ ORIGINAL A N/SRA-60 :1