A team of 5 met at 09h00 on Tuesday, 22 October at the Manor House at the base of Constantiaberg and took a leisurely drive up and around Elephants Eye Cave to where the mast is situated. The road was rough in a few places, but we all managed our way without any damage to our vehicles.

We could not have asked for better weather conditions, a beautiful summers day with no wind. The temperature was also very comfortable.

For some time, the repeater had caused interference when it rained and when the wind was blowing.

As we needed to climb the tower, we were reliant on Sentech employees to be present. On their arrival, they unlocked the gate at the base of the tower and work commenced. On inspection, it was found that the antenna cable going to the feed cable had chaffed through the outer casing and water had got into the outer plastic shield.

The antenna was replaced with a new one and all cables were tightly secured to prevent any movement on the cable. SWR tests were conducted before and after the antenna was replaced and a few tests were done with very good results (SWR and audio). Settings on the repeater were checked and all seemed to be in working order.

Once all the work had been completed, we had a lunch snack, compliments of David, ZS1DDK.

A final check that all was in order, and we slowly headed down the mountain. Today’s special thanks go to Schalk Burger (ZR1SWB), Rassie Erasmus (ZS1YT), David de Kock, (ZS1DDK), Michael Taylor (ZS1MJT) and LEM (ZS1LEM).

On Thursday 11 October, Mike ZS1TAF and Paul ZS1V took a day off work to take advantage of an opportunity to access the Constantiaberg Sentech site, home of the 145.700MHz repeater.

The site was last visited by Sean ZS1BSD and Paul ZS1V during mid-2017.  At the time, they diagnosed a problem with the antenna/feedline, but there were no Sentech personnel on site and so, despite being certified to climb, Paul could not attend to the antenna problem.  Since then, there have been numerous changes to the management at Sentech and communication has been difficult.  Gustav ZS1NZ, who works for Sentech, alerted the WCRWG to an upcoming Sentech maintenance run earlier in the week and so plans were hastily put in place for Mike and Paul to take leave and visit the site.

The team met the Sentech technician at the security checkpoint at 9.30am and proceeded up to the site.  Despite the warm weather at the bottom, a cloud on the mountain ensured cold and wet conditions at the mast.  The SWR at the bottom of the antenna feedline was measured at 2.5:1.  The high SWR presumably caused damage to the repeater which was transmitting well below 1W.

Despite the unpleasant climbing conditions, Mike headed up the tower to open and inspect the connection point between the feedline and the antenna, but this was found to be well sealed and dry inside.  He swapped out the antenna for another and the SWR was measured at the bottom at 1.3:1.  Paul swapped out the repeater and removed the bandpass filter for re-tuning.

The team left the site just after noon, to enjoy a cold one in a warm and sunny Tokai.

On Tuesday 25 July, Sean ZS1BSD and Paul ZS1V headed to Constantiaberg to attend to the 145.700 repeater which was transmitting, but not modulating.   The weather was only a few degrees above freezing and it was raining with only 10m visibility at times.  The lower part of the road was muddy an churned up by the heavy logging equipment in use in the area that is still clearing up the remains of the fire that devastated the area about 18 months prior.

Although the Motorola appeared to be working after a reset, it was removed for further testing and diagnosis and the PRF1050 backup repeater was installed in its stead.  The PRF1050 has been fitted with a new CTCSS decoder, courtesy of Sean ZS1BSD.  The required CTCSS deviation level is now more in line with typical commercial repeaters and not the very high levels required by the previous CTCSS decoder on the PRF1050.

Access to the site remains challenging.  Specific access arrangements had to be made with the nature conservation officials with the help of Sentech.

ZS1BSD appreciating the fine conditions