Repeater network status update, mid December 2015:
The 145.725 repeater located on the Radcliffe tower on Johan Rissik Drive near fort Klapperkop is functioning fairly well. Occasional bursts of interference are heard, especially in "drive time" as all systems get busy on the site. Noise overrides the weaker stations as the ctcss keeps the receiver quiet when the rpt is in standby.
In the North the 439.025 UHF linked repeater was swapped out for the third time in as many months. The original repeater was drifting after about 20mins use. The transmitter radio was swapped out, but suffered audio failure after 30 mins or so use. It is suspected that the duplexer is off frequency creating a high swr and consequent tx failure due to overheating. The original system has been operating without much trouble for approx 5 years. The second replacement repeater was fine on audio, didn't drop out, but has no CTCSS (88.5 out only) and suffers periodic lockup from a noise source on or near the site. A third repeater/link has been slotted in in the last week, but this seems to have an intermittent audio problem on the UHF TX. The latest system has excellent cooling and the duplexer is good, but the Vertex VX2100 transmitter seems to have a dry joint in the audio path.
Midrand's 438.825 link has a noise burst on the VHF link, it doesn't interfere with the 2m, but interference bursts are noticed on the UHF.
The central UHF repeater (co-located with the 2m on Radcliff) on 438.725 is still the temporary backup low power repeater. Johan ZS6JPL assures me he has made progress on the Motorola and has isolated the audio failure and awaits info on replacement parts. The Motorola boasts 50w continuous power, and has superb audio. we look forward to having it back on the air soon. Please feel free to use the frequency, it works well enough and is great when the 2m is busy.
Please enjoy the use of the repeater network over the holidays. I will attempt to get to some of the maintenance over the holidays, weather, schedule and funds permitting.
1) The linking adds a delay of 1.5 seconds between the UHF and VHF systems, don't be too hasty on the trigger ;)
2) Mobile stations have priority.
3) There is a 3 minute time out timer on the Midrand UHF link to 2m, keep overs tight.
4) Follow the amateur code when using the repeater. Courtesy toward fellow radio amateurs will go a long way.
73 de Craig ZS6RH