Aosc Merger with Scanner Digest Monitoring Times Ceases Publication 2012 Air Show Review Battery Tech
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survive in an electronic jungle. Information is abounding. Some of it re-hashed, much of it antiquated and ISSUE 64 APR-MAY-JUN 2013 surprisingly the areas that support “forums” are doing very well. The discussion boards on RadioReference are a very invaluable source of current information and the database ♦ AOSC MERGER WITH SCANNER DIGEST that has been compiled is second to none! ♦ MONITORING TIMES CEASES In the interim, Dave will include two more issues of his PUBLICATION publication to be placed within the Scanner Digest Newsletter. This issue will include their #206 and #207 will ♦ 2012 AIR SHOW REVIEW follow here on the next issue. We will continue to honor the remainder of AOSC subscriptions to former ♦ BATTERY TECH TIPS subscribers by providing them a PDF or printed version of ♦ PRODUCT ANNOUNCEMENT – the combined publication. Current and former column writers of AOSC are also welcome to submit material as DX EXTREME STATION LOG well. ♦ PRODUCT REVIEW – Scanmaster It was decided that both Dave Marshall and Lou Skyscan Desktop Discone Campagna collaborate their talents in an effort to maintain regional coverage to the scanner monitor community. ♦ AOSC SCANNERGRAM #206 Regional scanner coverage is one of the reasons publications like AOSC and NESN came about in the 80s. There was a need to fill the void, and regional publications were born. It is hoped than the wisdom and energy that GENERAL EDITOR Alan Cohen AOSC had will continue to live within the pages of the [email protected] Scanner Digest Newsletter. AOSC Joins Forces with Scanner Digest Alan Cohen, KB3QLE We like to welcome the AOSC and their flagship publication the American Scannergram to our newsletter. PUBLISHER Lou Campagna Dave Marshall has been involved with AOSC for many [email protected] years and he has attained a fine staff of column writers throughout the years. AOSC produced a niche publication After 33 years of service to the radio community, that provided not only local Ohio coverage but their writers Monitoring Times will cease publication with the who wrote about federal agencies were invaluable. The December, 2013 issue. information contain within the American Scannergram could be applied over the USA. http://www.monitoringtimes.com/index.html Today we live and play in an electronic playground where Some of us were shocked when heard that Bob and Judy we see the “print” media vanishing. Not only is this Grove have decided to close their publication. Many happening to hobby publications but it also is affecting hobbyist looked forward to each issue of their magazine magazines and newspapers too! which had the most comprehensive radio coverage that any publication of its type. Hobby publications have been hit hard since many of them don’t receive the financial support from product Dan Myers (K3NXX) writes: “Sorry to see this. I first manufacturers and dealers. The subscriber base is solely subscribed to M/T back in the '70s while still in high responsible to support such publications. Although we’re school. Back then it was a black and white newspaper. My happy to have reached Issue 64, remember that our scanner was a six channel crystal control, along with a bag of Issues 1 through 20 (June 1998 – July 2002) were crystals! I will miss M/T.” produced in a print-format. Sal Marandola (NC3U) writes: “Probably one of the best all- As previously explained, increasing printing costs, around radio hobby publications ever! As a ham operating on maintain a subscriber database and the associated HF and avid scanner buff, MT covered many topics of interest mailing expense made it cost-prohibited for this newsletter for me.” to continue in such a manner. The electronic publication was inevitable. So here we are! We are attempting to SCANNER DIGEST NEWSLETTER – ISSUE 64 PAGE 1 The new APCO P-25 Phase II system will be utilizing the AMBE 2 (Advanced Multi Band Excitation) for the digital Digital Scanning: A New Revolution in audio encoding, and then layering it upon TDMA or Time P-25, and why your scanner won't hear Division Multiple Access (for multiplexing.) AMBE 2 is that new 700 MHz system. similar to AMBE which is used in DSTAR, however a few tweaks and improvements were made to the codec which yielded AMBE 2. As a side note, the changes in code from By: Michael P. Mollet, N2SRO AMBE and AMBE 2 are significantly different which precludes the monitoring of a Phase II signal from a As many readers are aware, numerous public safety DSTAR portable. Besides not being able to decode the systems in the area will be migrating to the 700 MHz audio, the slots which were frequency dependent system within the next few years. As they do, many in the Phase I system (single slot per frequency) will now scanners will no longer be able to decode the signal. be multiplexed allowing for two talk channels per Some systems such as the city of Philadelphia, and frequency. This is due to the fact that in the TDMA Burlington County are using P-25 phase 1 systems, which method, Time, rather than Frequency is the slot for the fortunate can be decoded by use of a “Digital determining factor. Thus, in TDMA we can have multiple Scanner” such as the Radio Shack Pro-96 or GRE PSR- talk paths or slots per frequency. 500 to name but a few. These scanners however will not be able to decode the new 700 MHz systems when they As we can now start to see, the Phase II migration then, is go online as a new codec will be used. accomplishing two major upgrades: A codec simply put is the combination of hardware and 1: (taking a new digital codec (AMBE-2,) and software which is responsible for taking audio and translating it to a digital signal, and then being able to 2: marrying it with a new multiplexing system to allow for take a received digital signal and reconstruct it back into more talk paths per channel. intelligible audio. The codec employed in the Phase I systems which are currently in use and are nearing end of To add to the confusion, the new P-25 Phase II standard life expectancy are using an algorithm known as Improved applies only to trunked radio systems. There is no Multi Band Excitation, or IMBE for short (which has a sub- provision currently for simplex based P-25 Phase II. There component known as C4FM.) is controversy within the ranks of radio techs as to if tactical communications (simplex or talk-around) will use Some of the readers from the Trenton area may even be narrow-banded analog FM mode, or if they will revert to P- familiar with the precursor to IMBE which was known as 25 Phase I digital audio. Literature on the Motorola APX VSELP (pronounced Vee Selp.) This was not too popular portables seems to indicate that they are programmed of a format and therefore was quickly abandoned by all with both Phase I and Phase II codecs which would allow but a few agencies in favor of the much clearer and more for digital simplex communications, or even digital non- intelligible IMBE. trunked communications such as a conventional P-25 repeater. Though the above many be confusing, the In the Phase I system, FDMA or Frequency Division general take-away from this article should be this: Multiple Access is employed, which means that there are “slots” which are frequency dependent, usually reserving 1. Public Safety didn't necessarily start encrypting their one voice path or “slot” per frequency. The audio is traffic, rather, it is an entirely new language being spoken. digitized using a method known as IMBE or C4FM which stands for Continuous 4 level FM. (A lengthy explanation 2. If you have a digital scanner, keep it for now, see what on the C4FM architecture can be found online, but due to happens. If you do NOT have a digital space constraints here, will not be discussed further.) scanner, save your money and hold off on purchasing a new scanner. As the systems are rolled out, and Phase II An aside: A large portion of “P-25” trunked systems in our becomes more pervasive, the new Phase II codecs may Philadelphia area are not actually fully P-25 compliant. be installed in the new scanners sold. The APCO Project-25 standards specify parameters as to how a trunked radio system is to operate, to include 3. At this point in time, sit and wait appears to be the signaling, and even baud rates for the control channel. name of the game. At over $525 a pop for the What most systems in the area (to include the Burlington new scanners, this author will wait until the bugs are County p-25 public safety system) are doing is taking an worked out of the scanners before he purchases one. existing Motorola Type-2 Smartnet system and simply digitally encoding the audio using C4FM or IMBE. In this scenario, they are NOT fully P-25 compliant as they are disregarding some standards set fourth for the execution of the trunking. SCANNER DIGEST NEWSLETTER – ISSUE 64 PAGE 2 Where many hams are also scanner enthusiasts, we .Rig Control — Tunes/retrieves frequencies and thought to include some information that may be modes from supported rigs through integration with helpful to the hobby. DXtreme Software is proud to Afreet Omni‐Rig, available from Afreet Software. announce the release of: .QSL Processing — Creates QSL and address labels for physical QSLs, ADIF files for LoTW® signing in TQSL, DXtreme Station Log and ADIF files for eQSL.cc verifications.