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Latest posting was on 2020-04-08 in Watts Member login


2017-09-27 The 70cm Repeater at Midrand has been repaired. We had to replace a capacitor and currently been tested. Will be back on the air by Saterday afternoon. My apologies for the inconvenience. Die 70cm Herhaler te Midrand is herstel en word tans getoets tot Vrydag 30 September. Ons moes n kapasitor vervang en sal die Herhaler weer teen Saterdag middag in werking wees. Jammer vir die ongerief
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Midrand Link repeater back on the air!

On Tuesday afternoon Craig ZS6RH and Pierre ZS6PJH cleaned out the repeater and replaced the damaged cable and the siezed fan. All was tested on the bench and functioned well again. The power thru the duplexer was a bit low with 3dB loss, so that was tweaked back to 1dB loss, with around 10w out now. 

On Wednesday 21-04-2016 Pierre re-installed the repeater on the Midrand High site and it's working well again.  There is still work to do on Radcliff to optimise the antenna, this is in progress with a contractor appointed by the committee to handle maintenance on the towers.

73 de ZS6RH 

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Wonderboom 439.025, Midrand 438.825 Rpts off-line due to maintenance. 

 Please watch this space for further information as the Midrand repeater gets a service and new link radio, and Wonderboom undergoes a complete refurbishment.


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PARC main antenna destroyed by first storm of 2016!

145.725 on backup 2m antenna, 438.725 off the air.  Repeater coverage negatively affected. 

While we were all very relieved to have the first real rain of the season, the rain in the first weekend of the New Year came in the worst lightning storm of the season.

In previous years the installation, a co-linear near the top of the Radcliffe tower, was protected by the large aluminum monitoring antenna that adorned the top of the tower for the past two and a half decades. 

This installation was removed in winter 2015. After it's removal there was no spike placed on the top of the tower to discharge the static.

 PARC has permission to place the spike on to and replace our antenna system. We have "inherited" a second antenna, currently a 2-stack with a good 1/2" feedline, which will be upgraded to a co-linear for use on digital modes, both D-star and DMR eventually. 

The Repeaters survived, thanks to the superb earthing of the feedline and entry point, with the 145.725 coming alive when switched to the spare 2-stack visible in the pictures below the damaged dual band co-linear. Since the antenna is 2m dipoles only, the UHF is off the air.

UPDATE : Reports are that the temporary antenna is not performing well, with the Midrand link struggling to override the noise on the repeater input frequency in the mornings, some noise identified from a newly launched Chinese amateur satellite. 

I plan on getting a new antenna up before the weekend's bulletin.  

 73 de


Repeater custodian,


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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. 

Please remember:

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 

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