RTU-292 / Interface Unit

The RT U - 2 9 2 R a d i o / Telephone Interf a c e U n i t provides trouble- auto- matic connection between a radio system and a telephone system or other two- line. The unit is suited for use with HF, VHF, UHF, or satellite systems and is appli- cable to full-duplex or half-duplex modes. The unit incorporates a full-featured telephone set and monitor speaker.

ADVANTAGES The RTU-292 is an automatic telephone inter- connect unit for the connection of one tele- I Suited for Use with HF, VHF, UHF or phone line with one radio. It offers the flexi- Satellite Systems. bi l ity o f s e v e ra l mo de s fo r ma nn ed or I Unmanned Auto-Dial/Auto-AnswerCapability. unmanned station operation. I Automatic AdaptiveHybrid Balance: No When used in manual mode, first a radio-to- Hybrid Adjustments. radio link is established. Then, using the I DSP-Based VOX. telephone in the RTU-292, the operator places a call to the distant telephone that will I Sophisticated Call Progress Monitoring. be patched into the radio link. Once the dis- I Line Reversal Detection Going On-Hook. tant telephone party is on the line, the opera- I Radio Remote Control,Local Phone and ALE tor pushes a front-panel button to complete Interface Options. the patch to the radio link. The operator may communicate with either party using the I STU-III Interface Option. u n i t ’s handset, and may monitor both sides I Voice Prompting in Many Languages. of the conversation with the speaker. I Incorporates a Full Featured Telephone Set. The RTU-292 contains auto-dial/auto-answer I Front Panel Keypad with DTMF or . c a p a b i l i t y. This feature enables users to dial I Remote Dial-Through of Phone Numbers. from any phone system through unmanned radio stations into other phone systems. I Standard Telephone Operation Over Field Wire. RTU-292 Radio/Telephone Interface Unit

Since the RTU-292 has built-in optional remote control of . When equipped with the voice ed pair field wire. The VMR/Noise DSP (Digital Processor) Input and output levels are prompt option, the RTU-292 con- Reduction option uses a second VOX (Voice Operated Xmit) capa- adjustable to accommodate all tains prerecorded messages called DSP to provide high reliability bility, the voice on the phone line types of radio systems. A setup voice prompts that are played to VMR and effective noise reduction at each end of the link keys that mode allows the adjustment of guide the user in the operation of to HF radios. RTU-292’s respective unmanned signal levels without the need for the system. For example, a radio radio. external test equipment. user attempting to access the The Radio Remote Control Option system would hear the words uses the RT U - 2 9 2 ’s serial port to With its handset and front panel The PSTN telephone interface of “enter password”. When success- remotely control radios over tele- , the RTU-292 the RTU-292 contains a unique fully connected, the user would phone lines, permitting a user to may be used as a telephone adaptive hybrid circuit imple- hear “connection was successful, change internal radio parameters (independent of radio connec- mented with DSP. This circuit is proceed with your conversation”. such as mode, channel, or fre- tions) using either DTMF or pulse completely automatic, eliminating These voice prompts inform the quency of distant unmanned dialing. The handset may also be conventional VOX and hybrid user of the status of the system radios. Optional software is avail- used to transmit and receive via adjustments. The adaptive hybrid and the call they are placing, help- able for many kinds of radio the radio without a telephone achieves a balance on ing an inexperienced or infrequent remote control and different oper- connection. The front panel reactive phone lines and continu- user to know the status of the ational scenarios. includes pushbuttons for moni- ously adapts to changing line s y s t e m . toring the radio audio, telephone conditions, making operation The RTU-292 is set up to interf a c e audio, or both simultaneously insensitive to line impedance In addition to the HF ALE option cleanly with a for the using the front panel speaker changes. The unit has an RJ11C and the Voice Prompt option, the purpose of automatically sending and/or headphone jack. connector on its rear panel into RTU-292 can be equipped with a or receiving telephone calls over which a PSTN line, cellular tele- Radio Remote Control option, a an HF link using ALE capability. If The RTU-292 offers a standard phone, or satellite terminal can VMR (Voice Modulation a customer already has computer four-wire audio connection to the be plugged. Recognition)/Noise Reduction control of the HF ALE capability, radios with balanced/unbalanced option, and a Local Phone option. the RTU-292 may be interfaced to 600 Ohm or high impedance A 4-wire capability allows the The Local Phone option allows a the computer without any engi- interfaces. The unit also provides RTU-292 to interface a device like conventional telephone to control neering design modifications in a transmit PTT driver, receiver a STU-III secure telephone set the RTU-292 via a length of twist- the unit. COR input and serial port for with a radio.

The block diagram above shows previously-stored telephone num- case, the RTU-292 responds to Once the connection is estab- an application in which an RTU- bers. The command can be the radio command with a voice lished, the VOX in the RTU-292 292 is interfaced to a tactical or given by the radio to the RTU- prompt sent to the radio which keys the base radio when the airborne VHF/UHF radio system. 292 either via DTMF or a series notifies the distant radio user of party speaks. Note In this system, the RTU-292 is of “squelch breaks”, the number the selection he has made and that operation is completely auto- commanded from the distant of which determines the selected asks for confirmation of the matic and that the remote site radio to dial one of a group of . In either selection before proceeding. need not be manned. RTU-292 Radio/Telephone Interface Unit

The RTU-292 can also be used to telephone numbers and audio Store number in speed dial obtains the number to be construct a system which inter- over an HF ALE radio system. memory. dialed from the ALE’s order- connects two telephone systems The system includes, at each Recall a number from speed wire message buffer and dials via a half-duplex HF Radio link end, an HF equipped dial. the distant phone number. If without computer intervention. with ALE interfaced to an RTU- Cancel an operation. the link should fail, a voice In this situation, the RTU-292 292. Of course, the system is not Disconnect (hang up). prompt is sent and the user must be provided with custom limited to two stations, but may may then hang up or dial software to interface directly with include any number of stations, 4. If the ALE system is available, another number. the HF ALE controller if this capa- each with its own address in the the RTU-292 responds with a 9. The party at the distant bility doesn’t already exist. This ALE system. voice message. phone D answers and hears a system uses the Automatic 5. Using the telephone keypad, voice message that he is Message Display (AMD) message Main Operating Scenario the user enters the speed dial receiving a call via radio. He facility of a FED-STD-1045 User at the telephone set A code for the stored telephone may then key the transmitter Automatic Link Establishment desires to place a call through number he wishes to dial. If via DTMF commands or use (ALE) system to transfer tele- the HF system to distant tele- the desired number is not yet VOX (default) and talk to the phone numbers from the local to phone set D. stored in the RTU-292, the party who dialed at A. the distant station. The RTU-292 user may enter the informa- allows an untrained user who is 1. The user picks up the receiver tion manually. The number Call Progress Monitoring unfamiliar with radio operating of telephone set A and dials includes the address of the The RTU-292 contains sophis- procedures to make a telephone the number of the local RTU- distant ALE system plus any ticated call progress monitor- call over a radio link. A user 292 system. digits that must be dialed, ing which enables the distant must know only the following 2. The RTU-292 B answers with such as the area code, coun- unit to determine when a three numbers: (1) the telephone a voice message and waits for try code, etc. party has actually answered number of the local unmanned the user to enter his password 6. If the ALE system is available, the distant phone. This is nec- radio station, (2) his user pass- (password optional). the RTU-292 passes the num- essary because following dis- word, and (3) the destination 3. User enters his password and ber to be dialed to the ALE tant call dialing, several sce- code of the distant individual or the function code for placing a system’s orderwire message narios are possible: facility he wishes to call (if this call through the ALE system. buffer, and directs the system The call is answered normally. information has been previously The following functions are to link with the distant station. The call is not answered. stored in the speed dial memory typically available from the 7. At this point, the telephone A dead line results. of the RTU-292). RTU-292: user is given a voice prompt A busy or trunk busy is Place a call. stating that the link is being obtained. Block Diagram Description Monitor receiver audio. established. The call is answered by a The block diagram below shows Transmit/Receive via phone. 8. When a link is made, a voice or modem. the system connections and VOX on/off. message is sent to the phone equipment necessary to pass Key/unkey the transmitter. A, while the distant RTU-292 RTU-292 Radio/Telephone Interface Unit

SPECIFICATIONS Telephone Line Interface OTHER OPERAT I O N A L S C E N A R I O S Output Level to Phone Line Nominally -9 dBm (adjustable -12 to -6 dBm in 3 dB steps). Input Level from Phone Line Nominally -9 dBm (adjustable -12 to -6 dBm in 3 dB steps). The main scenario describes a call placed from telephone A to Response 300 Hz to 3200 kHz + 2dB. telephone D, but all other call Output Impedance to Phone Line 600 Ohms. combinations are possible includ- VOX Sensitivity 16 ± 2dB below input level setting (-25dBm @ -9dBm level setting for example). ing calls from 292 local phone C or RTU-292 B to distant points D, VOX Hang Time 11 second or 1.5 seconds, internally adjustable. E or F (refer to the block diagram Hybrid Balance/Adaptation Speed -30 dB over 300 to 3200 Hz within 1.25 seconds; measured below). (into 600 Ohms) witha white noise source. In another application, an ALE- Ultimate Hybrid Balance (into equipped HF radio may call into 600 Ohms) -50 dB typical over 300 to 3200 Hz bandwidth; measured with a single tone. either station shown in the block Hybrid diagram below and place a tele- Capability 0 to infinity Ohms complex impedance. phone call via the RTU-292 in the system. Phone Line Connections RJ-11C connector (J1) and screw terminals. Radio Interface (P1, DB-9 Male) Input Impedance Balanced or unbalanced 600 or 56k Ohms. Input Level -20 to -10 dBm, internally adjustable. Output Impedance 600 Ohms, balanced. Output Level -20 to -10 dBm, internally adjustable. Frequency Response 300 to 3200 Hz ± 2 dB. Key Relay Output Low level relay contacts, 60 VA max. Switching speed 5 msec. Telephone Handset (RJ-12C Jack) Electret , dynamic receiver. Dialing Modes DTMF, pulse at 10 or 20 pps. Pulse Dial Make/Break Ratio 40/60. Dialing Keypad 3 x 4, standard telephone layout. General Microphone Interface ALC (Automatic Level Control) having 30 dB dynamic range. Headphone Interface (Monaural Drives high, medium, or low impedance . Delivers not less Phone Jack) than 10mW into 600 Ohm headphones. Speaker Driver Power 4 W min. @ 10% distortion. Internal Speaker 3 inch square, 3.2 Ohms. Indicators Indicators for each push button, plus peak level and keypad LEDs. Front Panel Controls Power on/off switch, Dialing keypad, Speaker volume control, Phones volume control. Pushbuttons: Tel-Line-Phone. Tel-Line-Radio, Handset-Phone, Handset- Radio, Speaker-Phone, Speaker-Radio, Tel-VOX, Manual Key, Auto Ans., Auto Ring. DC Input Power +11 to +15 VDC or +22 to +30 VDC, 1A maximum. JPS , Inc. AC Input Power 115 or 230 VAC ± 15%, 47-63 Hz, 20 VA typical, 50 VA maximum. 5800 Departure Drive Raleigh, NC 27616 Size 3.5”H x 19”W x 10”D (6.9 x 48.3 x 25.4 cm). Weight 12 lbs. (5.5 kg). Phone: (919) 790-1011 Fax: (919) 790-1456 Operating Temperature -25 degrees C to +55 degrees C. E-: [email protected] Web: www.jps.com Storage Temperature -40 degrees C to +85 degrees C. Specifications subject to change without notice. Humidity Up to 95% @ 55 degrees C. NXU-2™ is a trademark of JPS Communications. Copyright © 2003 JPS Communications. Shock MIL-STD-810D, method 516.3 procedure VI. All rights reserved.

Options Radio remore control, VMR/noise reduction, Local phone, ALE control, Ver.1 8/20 Voice prompts, DTMF telephone. Vibration MIL-STD-810D, method 514.3 category I.

DS-RTU292-01