When KG4WBI decides to do something, he does it right. So we finally got a stable repeater operating at the repeater site. It has a little bit of a hot receiver, but it is working so we are not complaining.
Above you can see the new and improved KG4WBI 1.25m repeater in operation! This system works like a charm and we have been happily giving it a good work out ever since he built this out.
Up till recently we have been using an old GE Master II (2 meter repeater) that has been retuned to work on 1.25 meters. This was apparently no small feat either as there were extensive notes about what had to be done and all the new information was written out meticulously. This was nice as we soon ran into a problem with it due to the old solder joints and corroded connectors were making it have a plethora of problems. We would chase one down and get it fixed only to find another one a day or two later. What clued us in that we had a good location for the repeater though was that we had found out that we had been talking on the repeater with the finals shut down so it was literally transmitting with the preamp, we found it in the manual and it was something like 90mW if I remember right. I can be wrong here, but that is what I think it was… needless to say it wasn’t much, and were able to ragchew on it and have a great time for the most part. So the tuned repeater antenna up 50 feet above the grade on the brow of the mountain was an excellent location.
Here you have yours truly putting the coax on the wall with plastic “one hole” style tie downs. We wanted to do this so that it wouldn’t risk crushing the coax as we tighten it down.
Well the preamp finally went out too and we actually had to shut the repeater down for a while till we could go work on it. So we get a day and go trouble shoot on it a while and the problem comes and goes while we are there looking at it and the silly thing even juiced up the PA for a few minutes to full output while were testing into a dummy load. Then it all went out again and there was nothing we could do without an oscilloscope to check for signal. At this point we shut it back off and go home to look at oscilloscopes to see what we could find that would work up to 250mhz…
In the mean time, Roger gets out a couple of mobile 222 radios he has and orders a Hamgadgets repeater controller off the interwebs. He then proceeds to build a working repeater out of these two radios with only a couple of slight modifications and just goes to the site and temporarily connects them to the existing duplexer and powers the system on. It takes him a few minutes to get a few of the settings right and BAM! The KG4WBI 1.25m repeater is back on the air! These radios work surprisingly well too. We ran it like that for a few weeks with the radios laying on a 5 gallon bucket if memory serves. Well, once we figure out that these radios work fine in this role, we decided to make the install a little more permanent and get all the repeater parts out of his son’s way so he can work on cars again… lol. You see, his son wants his garage back so he can tinker on project cars…
The antenna is sitting on top of a 48’ push up pole that we guyed too to the site once we got it raised just to eliminate any chance of wind blowing it over. The power supply below was chosen for the main power supply should we choose to run it on mains again directly at some point. So this is here for that expansion should we choose to do it.
Instead we chose the route below. We have a 10 amp smart battery charger wired to these batteries and since we are only running 25 watts, the whole thing only draw about 7 or 8 amps on transmit. I want to say we tested it and measured right at 7 amps on transmit, but this means that if the power fails for any reason, this repeater will not miss a beat for many hours. something on the order of 30 straight hours of transmit… Which means in reality it will last 2 or three days of casual use before the batteries expire. By then we will have been able to take some solar cells to the site or even a small generator should we want it to stay online past that. Most power outages for us in this area will last less than one full day so this means we should never have the repeater go offline for power failure 99% of the time.
As you can see above, Roger also installed a copious amount of these RFI chokes on the power wires everywhere! These work reasonably well and are really easy to install so there isn’t really a reason not to take the precaution and use a few of them. We were hoping to suppress and RFI coming out of the smart charger and as far as we can tell, either the charger has good radio noise suppression or these chokes did the trick…or a combination thereof.
Below you can see one of Roger’s experiments. This is part of the “if one is good then two is better” plan. He is testing how clean the skirts are with the smaller duplexer wired in series with the larger one. It has incredible sensitivity on receive without even a hint of the transmitter RF in it. I think this actually worked… Out of this duplexer you see the coax going into the lightening protector which is grounded with that huge ground wire you see in the photo. The coax then comes out of the lightening arrestor and heads out to the antenna with LMR 400 DB.
I just wanted to share something about ham radio that wasn’t a POTA activation for a change… lol. Thanks for reading along and 73
WK4DS - David