Metrocrest Amateur Radio Society

Musings from the Vice President

August 2017

    This month we will be discussing Radio Code-Plugs, the new DMR Android phone/radio (yes I mean a combination android cell phone and DMR/analog UHF radio), and the upcoming speaker topic for the August MARS meeting at the Hebron public library, 10th of August, testing at 6:00 PM, meeting at 7:00 PM.

     First the speaker topic: It’ll be knots, knots, and more knots. Titled “Knots for Ham Radio,” Steve describes the presentation as Knots in feed line are a bad thing. Knots in rope can be good and bad. At the August meeting of MARS, we will be learning and practicing tying several simple knots I have found useful in ham radio. Rope will be supplied, so come learn about useful knots and the best situations to use them.”

     So untangle yourself from what you are doing and come by to see Steve, KD5YPB, tie himself up in knots!

     For next month, we are working very hard to get a Skype presentation from a major Amateur Radio vendor, stay tuned for more details.

     Those of you who are interested in doing a presentation for our club or would like a topic done, please email me at vpresident@kb5a.org.

     Second item: Code-Plugs—How I Learned to Stop Worrying and Love the BOMB. Uh, oh, I mean DMR radio programming (with apologies to Dr. Strangelove).

     Those of you who know me well, know I love all things digital when it comes to amateur radio. I believe this comes from the fact that in my early days as an electronics technician I could troubleshoot digital TTL and CMOS much easier than analog circuits, especially switching power supplies. But I’ve run into problem with Code-plugs and DMR radios. What is a code plug, you say? Well for you Non-Batwing (Motorola) fans, the following is taken from this website: http://batboard.batlabs.com/.

     “A Code-Plug is basically a program that’s loaded into a radio and tells it what frequencies to transmit and receive, RF power output, carrier squelch/coded squelch, signaling modes, and whatever other features the specific radio might have you want enabled.”

     Back in the good old days, radios used crystals to control the frequencies, and sometimes had internal jumpers that were set for various options. Later options moved to a jack on the back of the radio. Service technicians (and hams) configured plugs with wire jumpers in them that plugged into the jack to enable the options. These became the original “code plugs.” As time went on more things were controlled by these code plugs - such as tone encode/decode. 

     As radios became microprocessor controlled, the external code plugs moved inside the radio as programming information. The term has, unfortunately, remained with us, although there’s not much that still plugs in. The code plug contains the operating frequencies, tone selections, timeout values, system IDs, etc. In some instances, there’s are even parts of the program itself in the code plug which defines a radio’s personality. These days, the code plug is just a relatively small binary file that’s managed by the programming software (called RSS or CPS or similar) and transferred to or from the radio via several proprietary means.

     I love DMR, DSTAR, and FUSION radios. With DSTAR and FUSION I can program my radios with RT System software. Not so with DMR radios. You have to program a code plug usually with a weird Chinese program that comes with the radio or an expensive and hard to find and use Motorola program for Batwing radios. You need to know a lot of parameters and as with most things, you can’t guess at it.