2017-07-26

Callsign Cobwebs From The Mental Attic

Heard some chitterchatter recently on one of the repeaters regarding callsign structures. I thought I'd clear out some of the stuff in my mental attic, so here goes:
  • By international treaty, the USA is allocated W, K, N, and AA-AL, technically WAA-WZZ, KAA-KZZ, NAA-NZZ, AAA-ALZ (AMA-AZZ being allocated to other nations).
  • Internally, the FCC decides how to break up those allocations into the various services.  
  • Way back in the day, when their were true regional offices for the Department of Commerce (before the Federal Radio Commission or the Federal Communications Commission), each district office had a number. Oklahoma's licenses were handled out of the New Orleans office, which was #5. You see where this is going.
  • Initially, US hams got a number (corresponding to the issuing office) and then letters assigned in sequence starting at AA. When they got to WZ, they started again at AAA (because for a while, if the first letter after the number was X, Y, or Z, it had a special meaning). There was also a period when some stations, usually a portable station operated by an amateur away from his usual address, that had 4 letters after the digit.
  • After one of the international radio conferences, c.1923, everyone agreed that all callsigns should start with the letters that had already been assigned, so US hams all grew Ws ahead of the digit.  
Skipping LOTS of trivia ...
  • For about 40 years now, more or less, in the Amateur Radio Service, callsigns have been grouped. Amateur Extra Class licensees were assigned calls from Group A, 1x2 or 2x1 starting with W (e.g., WE5Z, W5TC) . When those ran out (and in the 5th district they ran out about 1992 or so) they "refreshed" the group with calls starting at AA5AA. Advanced Class licensees (none issued since 2000) got calls from Group B, 2x2 starting with K (e.g., KK5IO). Technicians and Generals got assigned calls from Group C, 1x3 calls starting with N (e.g., N5ZZM). Remember, until 1987, the only difference between the test or Tech and General was the Morse code, so they got calls in the same group - the written exam was the same and if you passed the 13-WPM test, you got General, if not, you got Technician. Group C was exhausted in our district about 1992 as well (N5ZZM just squeaked in!) Novices (none issued since 2000) got calls from Group D, which were 2x3 calls starting with K. Once Group C was exhausted, instead of "refreshing" it with some other pool, the FCC started pulling from Group D, which is why all new Tech and Generals get 2x3 calls.
  • Now, then. When it comes to vanity calls, you are still restricted to the group that corresponds to your license class. So Technicians and Generals can get any available 1x3 callsign (starting with an N, K, or W) or any available 2x3 call (starting with WA-WZ, KA-KZ, NA-NZ, or AA-AL) with some restrictions. To get a 1x2, a 2x1, or a 2x2, you have to hold an Amateur Extra license.

References








Edit: Looks like Group A in the 5th District was exhausted on 1987-06-02 from looking at QRZ's 1993 database causing the FCC to start at AA5AA after WZ5Z was issued. 





2017-06-03

OUARC Repeater Update

Your host is not only the Technical Committee Chair for SCARS but also a member in good standing (and past treasurer) of the OUARC so he ends up working on the OU repeaters, too (D-STAR on 444.7500 MHz, DMR on 443.8250 MHz, and good old FM on 146.8800 MHz).

Several weeks ago, the DMR system fell off the network. The RF side was still up and usable on the local talkgroups; only the remote talkgroups were unusable.  N5HZR and your host visited the site and were able to get the repeater connected back to the network.  

The next week, same thing.  Appeared, over the network, to be the same problem so your host visited the site but determined that the repeater was unrecoverable.  What your host didn't realize, possibly because the lightning was closer than absolutely necessary, was that the .88 FM repeater was also dead.  

Another visit was organized and it was determined that the power supply for the .88 repeater had taken a hit.  We removed the power supply as well as the DMR repeater as both would need to be repaired.  We're not 100% certain, but we are assuming that Thor played havoc with the equipment.

Forward to today and N5HZR, AG5DV, and your host returned to the site with a new DMR repeater (the other is being repaired and will be used elsewhere) which was placed in service.  We have some other clean-up work to do there so we'll be back soon.  Hopefully, we'll have the repaired power supply for the .88 repeater by then and we'll get that back on the air as well.


2016-11-12

Nearly Thanksgiving Update

This update was delayed in the hope that the Stadium Remote would be back in operation, but that has yet to happen.  There are, however, other developments, most of which are probably generally known by now through other channels (RF channels, maybe, even).

Members of the Technical Committee mounted several expeditions to the County Yard in September and October.  Over the course of the visits, the following tasks were accomplished:
  • Replaced the Arcom RC-210 repeater controller;
  • Wall-mounted and connected the Telewave multi-coupler ("cavities") for the NORMAN APRS digipeater;  
  • Wall-mounted the existing Wacom duplexer; 
  • Installed the new radio for the digipeater and a new cabinet shelf to hold it and the TNC;
  • Relocated cabinet to allow more county equipment to be installed.

Cabinet with digipeater, repeater controller, repeater and power supply.
Above cabinet is multi-coupler (toward the rear) and duplexer (toward the front).  


Three things were driving these recent efforts.  Back a few years ago, the county needed to use one of the "retired in place" antennas that SCARS was using for the digipeater.  The expectation was that the county would only be using that antenna for a short period but that ended up not being the case.  No matter.  In the meantime, the RF portion of the digipeater was replaced with a new transceiver and, as noted, a shelf for it was built in the existing cabinet.  More importantly, the system was re-engineered to use a multi-coupler between the club's main two meter antenna and the duplexer for the repeater.  This allows both the digipeater and the repeater to use the same antenna at the same time without interference.

The needs of our hosts, Cleveland County, were the second driver.  The sheriff's office is in the process of installing new radio equipment at the county yard and SCARS needed to "reduce the footprint" occupied by club equipment.  With the wall mounting of the duplexer and new multi-coupler and inclusion of the digipeater in the cabinet that houses the repeater, this has been accomplished.

Lastly, the repeater controller needed to be returned to service.  The RC-210 controller was checked while it was out of service (See entry from July 10).  Unfortunately, no trouble could be found on the test bench.  When being re-installed, it was noted that the serial port interface was not behaving correctly as the configuration could neither be updated nor retrieved from the unit.  Reloading the firmware seemed to correct this issue.

Since the ATA that connects the controller to the PSTN was found to be dead and the WISP that has equipment at the same location had also needed to replace some equipment around the same time that the repeater controller failed, the general consensus of the Technical Committee was that lightning got into the building at some point this past summer.  If this is indeed what happened, it is entirely possible that the programming of the controller became corrupted without the controller itself being physically damaged.  Members of the TC will be monitoring the controller's operation in order to determine if there are any other anomalies.