QSO #4 — When a repeater isn’t a repeater….

I had an inspiration today that instead of the usually more ‘instructive’ blogs — telling you about some technical part of ham radio — that I would take you along on a journey which explains why this hobby still engages and attracts me almost 55 years after I started it.

Let me tell you a story…. All settled in?? Good, let’s begin….
A few years ago, before I came to the Oceanside area, I was part of a ham radio club in Victoria. At one of our regular monthly meetings, we had a presentation from a ham up in Nanaimo about a ‘new’ technology called Digital Mobile Radio (DMR) which was sprouting up all over North America and particularly in the BC Lower Mainland and the Island. (I’ll do a whole separate blog on DMR, don’t worry). It sounded pretty neat and the ‘cost to enter’ wasn’t that bad — basically about $200 for a 5W hand-talkie. I found one that was dual band (2m and 440) which would also do normal ‘analog FM’ stuff, so I thought ‘Why Not?’ I can play with the new stuff, see what it’s all about and also get another handheld to boot. (At this point, I already had three other 2m handhelds, but what the heck????)

I enjoy playing with new technologies to see how they will fit in and extend my ‘station’ and involvement in the hobby. As I started playing with the unit, I learned more and more about DMR and the various nuances of programming DMR radios (or so I thought). Unfortunately, although one of the local repeaters in Victoria had been set up for DMR, there wasn’t a lot of interest on the part of other hams in the area to actually ‘do’ anything with it. So, the unit mostly just sat on the shelf.

Fast forward to last February 2021, when we moved up to the Oceanside area. Amongst the many hams welcoming me to the community was Bill VE7EVS — a wonderful older Dutch gentleman with a wry wit and a vast knowledge of radio communication technologies, based on many, many years in the industry. Bill and I hit it off very quickly. He and I share a delight and fascination with new technologies related to radio communication and we both very much enjoy ‘tinkering around with stuff’ just to see how it works and how we can make it work better.

Through various machinations, Bill had found himself in possession of a pair of Motorola transcievers from a previous repeater site and he immediately set upon gathering the extra stuff needed to hook them up to the internet, etc. to make them work as a DMR repeater for the community. Yea, it wasn’t located on a mountaintop so not the most IDEAL location for a repeater, but ‘what the heck… let’s see if we can get this thing working and let people use it.’ After some back and forth on configuration parameters, antennae and testing of coverage range we had it working pretty well. I was thrilled to find out that I could easily hit Bill’s repeater from my location in French Creek! I regularly used it to check into various DMR nets in the Pacific Northwest and BC. Occassionally the repeater pair would be unavailable as Bill was either ‘playing with them’ or had forgotten to turn them on that night. No worries. Our goal and biggest challenge was to make the repeater available to other DMR radio owners in the community and encourage them to take advantage of it. The other challenge was to limit access to the repeater to local operators and not have it overwhelmed by operators using the ‘Worldwide’ talk group that come across the internet connection. We talked about many options, including use of ‘local’ talk groups, restricting some talk group access, etc. None of them worked ‘completely’, but we were making progress.

Then, about 2 weeks ago it stopped working for me. I would try to access the repeater and I could ‘hear’ it (i.e. I could hear other people using the repeater on the nets) but whenever I tried to access it, I would get a ‘repeater not found’ message. Hmmmm… I know I hadn’t changed any of my settings so I headed over to Bill’s place to see what was happening. Bill wasn’t aware that he had changed anything either, but we agreed that even though I was now located RIGHT BESIDE the receiving antenna, it couldn’t be a problem with propogation and or distance to the repeater. It was a real puzzle since Bill, using his handheld DMR walkie-talkie could access the repeater from all over the Parksville area and even while I was sitting right beside him! What could be going on???

After some further investigation and help from other hams with DMR handhelds, we discovered that the repeater was now rejecting input from anyone except Bill’s handheld! As I mentioned, I’ll talk about more about this in a future blog, but DMR transmissions include a unique ‘ID’ for each user and repeaters access that ID when deciding what to do with the input. It appears that, in the past, we had Bill’s repeater configured to act like a ‘normal, analog’ repeater in that it would simply retransmit everything the receiver picked up. Somehow, in the intervening time, the programming in the repeater had changed so that it now would only retransmit stuff that it thought came from Bill. It sounded implausible, but I’m a great believer in the quote from A. Conan-Doyle’s Sherlock Holmes character “…when you have eliminated the impossible, whatever remains, however improbable, must be the truth…”. So, we reconfigured my radio with Bill’s DMR ID and voila! I was able to access the repeater. And we found the same thing was true for handhelds from other hams Bill was working with. OK, now we’re a little further ahead. At least we can work around this for now while we find out what’s changed. I had high hopes that with my radio reconfigured with Bill’s DMR ID that I’d be able to resume handling the Wed morning DMR ‘gathering’ after my stint on the Breakfast Bunch. Guess what???? It didn’t work…. Again, I could ‘hear’ everyone on the talk group, but I wasn’t being re-transmitted. And then, eventually, it all went completely silent — I couldn’t hear anything from the repeater at all.

Back to Bill… (remember, Bill and I have ‘fun’ with this…). Well, it turns out that something went haywire with the transmitter portion of the repeater and it stopped working completely! It doesn’t explain why I couldn’t access the receiver portion with Bill’s DMR ID, but at least we knew why I couldn’t hear anything.

So where are we now… as of today (Sunday, Feb. 20th) we have the repeater mostly working again. Bill found that there were some configuration parameters incorrectly set, so that’s why the transmitter stopped working. (Fortunately, it wasn’t damaged components!). And we’ve got the repeater now accepting calls from other people besides Bill’s DMR ID. We’re not exactly sure what changed, but at least we’ve made progress. Now, it appears there is some reason why my signal to the repeater is showing up as very low — not quite enough to trigger the receiver. Again, this is weird, because it worked fine before and when Bill flips the receiver into analog mode (i.e. not digital) my signal shows up as full strength (‘full bars’ as we say in ham jargon, based on the front panel display) More testing required!!! I’m going to try recharging the battery and see if that helps. (Unfortunately, the Alinco handheld I’m using doesn’t have any way to operate under wall power — only via the batteries.) And I may take a bit of trip out to Bill’s place using the rubber duck antenna and see if things change as I get closer to his place. I’ll also have to look into whether there’s a bigger battery pack available for the Alinco. 🙂

Yea, it sounds like a lot of heartache and work just so we can play with a new ‘mode’ of communication. But as I said at the beginning, this is one of the great parts of the hobby — the exploration and experimentation to see how these things work and how to make them better and more accessible to other hams. It’s one of the parts of the hobby I love.

Hope you enjoyed the story/journey. Next time, we’ll get into more about repeaters work and how they make our ham lives easier and much more rewarding. 73!