Category Archives: Maintenance

Constantiaberg maintenance

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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.

 

Hanskop rebuild 2018-09-09

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On the morning of Sunday 9 September, a team consisting of Jan ZS1VDV, Mike ZS1TAF, Rassie ZS1YT, Paul ZS1V, Ohan ZS1SCI and JP ZS1JPM headed to Hanskop to perform a major site re-installation.

Approximately two years ago, the tower at Hanskop blew over in a storm and all the antennas of the tennants on the site have been temporarily mounted on the building ever since.  The new tower and cable trays have been recently installed and once the owner of the site had moved his own equipment on to the new tower, we were invited to install next.

The journey to Hanskop has become quite challenging.  The usual access route has been all but washed away, necessitating navigation along some even more minor tracks.  Even those are flood damaged and deeply rutted, some with pools of water 30 to 40cm deep and 50 or 60m long.   The weather on the morning was cold – around 4C – but Hanskop was uncharacteristically wind still and so all team members jumped into action after arrival on site at around 9am.

While one group removed the temporary antenna pole from the side of the building and removed the antennas from it, another re-organised all the equipment in the rack, moving the equipment up to make space for the new battery backup system at the bottom of the rack.

New backup batteries

Rassie ZS1YT constructed a shelf to go over the batteries, allowing the duplexer and bandpass filter for the 2m repeater to stand above them.

Duplexer and battery charger on shelf

Equipment reinstalled

New cable gland plates have been installed in the building. New RG214 patch leads for inside the building were made up and attached to lightning protection devices.

Feedline connection points for the 70cm repeater, 2m repeater and 70cm link to Jonaskop

Outside Mike ZS1TAF was left to solo all the tower work after Paul ZS1V was unable to climb due to illness.

Mike attaching the feedline to the link antenna

Mike attaching the UHF repeater feedline to the antenna

Mike installed the three antennas, attached their feedlines and secured all the cables to the mast.  On the ground, Jan ZS1VDV and the rest of the team prepared the feedlines, installing the connectors and routing them in the cable trays to the exterior of the gland plate.

Feedlines being secured

Feedline wrangling

Final measurements showed the antennas reacting well.

Antennas installed

The team packed up and left site just after 3pm.

Maintenance Hanskop 20180707

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Jan (ZS1VDV) and Rassie (ZS1YT) went to Hanskop reconfigured the repeater controller and did all measurements for the big site power upgrade and antenna migration.

Most site visits starts the evening before the time with a 1 hour planning and packing session.

Tools and Spares for trip

Wake up 06:30, pack vehicle.

Leave for Strand 07:30 from Stellenbosch.

Pickup key 07:45.

Drive to site, which was very long and challenging drive. Had to “find” a way to the top.

“Finding” the road

MMMM, where to now?

Some holes with bakkie for size reference

08:45 arrive on site.

With all the power interruptions and no backup power, the site controller’s EPROM got corrupted. Reprogrammed the controller. Changed default for links to VHF and East. (please see updates DTMF updates on Hanskop)

Did some detail measurement for coax and battery placements.

10:00 left site.

11:45 Home in Stellenbosch

12:00 Finished unpacking.

Bottelary Maintenance 20180629

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View from top in mist

Mast in mist

ZS1SCI (Ohan) and ZS1VDV (Jan) went to site around 17:00

UHF repeater ZU9DMR running DMR, D-Star and YSF

The reconfigured UHF repeater ZU9DMR was reinstalled on site.

A new gateway was installed for the VHF D-Star repeater.

Last view of site, with alarm activated

The site was left around 18:45.  The drive down in the dark and mist was a big challenge.

Jonaskop Maintenance 20180324

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Jan ZS1VDV and Paul ZS1V left Stellenbosch at 10am for the Jonaskop repeater site, home of the 145.675 repeater.  It has been some time since the last visit to the site and the access road condition has deteriorated significantly.  Somewhat delayed by a puncture to one of the bakkie’s tyres, the team arrived on site just after midday.

Antenna SWR measurements on the VHF stack and both link antennas were found to be acceptable.  Output power of the repeater and both links, was also as expected.

Jan patched the link controller to take care of a slight crackle on the audio, most easily noted in the 2m repeater tail.

Jan busy with the link controller

Some more tests pointed to a problem with the Hanskop link radio (possibly off frequency).  This was removed and the team departed at around 15:00.

Pleasant conditions at around 15C, overcast and no wind

Local population

Jan and Paul arrived back in Stellenbosch just after 17:00.

Maintenance Piketberg, Hawequa and Bottelary 20180113

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Jan (ZS1VDV) and John (ZS1EQ) did a round trip to service 3 sites.

Started to load the bakkie 07:00.

Left Stellenbosch around 08:00 and reached Piketberg by 09:45

At the end of 2017, the Piketberg VHF repeater was removed.  The repeater was serviced by Verstay.  The final transistor was replaced.  A replacement duplexer was prepared during the week. The duplexer was swapped out and VHF repeater reinstalled.  SWR between duplexer and VHF radio was 1.2 and between the duplexer and antenna 1.3.

Left Piketberg 11:15 and was on Hawequa at 12:45.

The 10 amp battery charger was swapped out for a 7 amp battery charger.  The 10 amp is designated to go to Hanskop.

Left Hawequa 13:45 and reached Bottelary at 14:45.

Removed the UHF DMR repeater for service.

Back in Stellenbosch and unpacked by 16:15.

Maintenance Back2Back 20171209

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The UHF back2back link was moved from the QTH of ZS1DDK to Libertas on 4 November by ZS1DDK and ZS1TAF.

More maintenance was done today by ZS1VDV and ZS1TAF.

Today the equipment was moved on to racks in the cabinet and a link controller was installed.  A powerpole distribution block was added and all power connections migrated to powerpoles.

Rack with radios and controller

This controller can now be used to link or unlink the back2back via DTMF codes.

8500 = Link

8504 = Unlink

Helderberg 70cm DMR repeater installation

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On Wednesday 27 September at about 16:30, Paul ZS1V, Jan ZS1VDV and Wiaan ZS1WB met a representative of our Internet sponsor at the Helderberg high site to install one of the WCRWG Motorola SLR5500 DMR repeaters.  The Helderberg high site is one of the easier ones to access due to its relatively low position at around 500m ASL and its proximity to the urban area of Somerset West.

Despite the relatively low elevation in comparison to other WCRWG high sites it is quite prominent above the 100m ASL average ground level.  Good coverage is expected over most of the False Bay side of Cape Town, the Cape Flats and Northwards to Stellenbosch.

The team installed a Webb HD400 UHF dipole antenna and a short run of about 8m of EC4-50 Heliax.  Shielded and UV resistant UTP cable was run from the repeater enclosure to a nearby enclosure for the DMR repeater’s Internet access.  The SLR5500s configuration was updated to reflect the new IP environment before everything was tested and found to be satisfactory.  Antenna SWR was measured at 1.2:1.

A first QSO on the new repeater was had on talkgroup 655 between Paul ZS1V and Koos ZS5KDK before the team wrapped up and left the site just before 19.00.

Maintenance Constantiaberg 2017-07-25

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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

 

Maintenance Hanskop 20170722

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Jan (ZS1VDV) and Rassie (ZS1YT) went to Hanskop to investigate the controller not responding to DTMF.

Started packing vehicle 06:30, left Stellenbosch 07:00.

Had to drive very slowly up as the road is in very bad condition and had the sun just over the horizon.

On site by 08:15. The temperature outside was 1.2 degrees, the wind was cutting through everything.

The problem with the controller was found to be interference on the 145.600 Repeater.  The interference is not from our equipment but most likely from WISP equipment.
The 145.600 repeater’s SQL was closed to 1.1uV (about 4 times more that what it should be).  This only helps about 80% of the time. The interference will need more work/investigation.

All SWR was checked. VHF repeater (1.1), UHF repeater (1.1), Jonaskop link (1.6).

CTCSS was added to the 434.650 repeater.

Home at Stellenbosch by 12:45.