Hermanus move and install Q4 2022

On 17 December 2022, a project which has been in the making since August came to fruition.

The high site which previously hosted the 145.725 MHz Onrusberg repeater since late 2016 was taken over by new management.  This marked the end of good relationship over many years.  The farm on which the Onrusberg high sites are located also got a new owner, further complicating matters.

After some investigation, negotiations and leveraging of existing relationships, a new high site became available.

The started a string of visits (anything between 250 km and 300 km per trip), hours of planning and preparations (including a few trips to buy and pickup stock).

First was a site inspection by ZS1TAF and ZS1V.

During a second visit (4 October) the antennas (folded dipole for VHF and dipole for UHF) were installed on the mast by ZS1TAF, ZS1V and ZS1YT.  This was a long and complicated day, as this was not an easy tower to climb and work on.  Thanks go especially to ZS1TAF for the donations towards antenna pole and brackets.  Over 60m of half inch EC4-50 feedline was installed.

ZS1TAF on mast

Third visit (19 November) was cabinet, cable trays and power articulation by ZS1DDK, ZS1TAF and ZS1YT.

New cable tray and cabinet

Preparation for the fourth site visit was still going strong until 01:00 on the day of the visit.  The morning continued at 05:30 and packing all the equipment for the installation and possible eventualities required detailed planning.

ZS1MTF arrived at 07:00and there was just enough space in the double cab bakkie for all the required equipment (2 toolboxes, 8 ammo crates, test equipment, ladder, duplexer, repeater, link controller, link radio, power supply, charger, transfer box, battery, among many other items).

How much more stuff do we need to pack?

ZS1Z and ZS1MTF arrived on site at 09:15. The mist and clouds was thick, with visibility as poor as 5m at times.

After this, the layout of the cabinet and all DC wiring was completed.  The DC system includes a 20A linear power supply, a 200 A/H battery, a 30 A charger, an automating transfer switch, and low and over voltage protection box (donated by ZS1EQ), fuse boxes and lots of crimps, power poles connectors and cable. LoRaWAN based telemetry was also installed.

Cabinet with all equipment installed

Next the link controller cabling and sensors were installed.

Lightning protection was installed and new RG214 patch leads were made up and installed for the last section of the run from the antennas.  This is always something which takes much longer that expected and uses many more cable ties.

Next the duplexer was installed on the wall.  The bracket on the duplexer made it very uncomfortable process.  Great care must be taken when handling the cavity filters as the duplexer had more than 10 hours of setup in it alone. The harness is the correct one for the amateur 2m band, and some of the cans have some age on them, and do not want to adjust without some persuasion, all of which complicates tuning.  A one port circulator (isolator and bandpass filter), was also installed

Crimping of all internal coax and patch leads (RG223) followed.  The double shielded coax crimping must be done with great care.

Duplexer and circulator on the wall

The antenna SWR was checked and found to be in order although the VHF was at 1.5:1, somewhat higher than the expected 1.3:1, and will be investigated on a future visit. The UHF link was at the expected 1.1:1. All outside connections was sealed Scotch 23 and electrical tape (Nitto).  The cable trays were closed again with all stainless-steel straps reinstalled and some extra cable tie straps for extra ease of mind.

Outside cable trays

Some radio checks were completed with ZS1L and ZS1YT.

The road home was clear but long, after dropping of all the keys and unpacking the vehicles everyone was home by 22:00.

This concluded the move and upgrade to include backup power and circulator.

As with any move of this magnitude, some small gremlins may pop up, please report as per the weekly status reports. Thank you for all the support.

Onrusberg visit

On Sunday 4 November, a team consisting of David ZS1DDK, Jan ZS1VDV and Paul ZS1V visitted the 145.725 repeater site at Onrusberg with the intention of returning the repaired Tait repeater and retrieving the Kenwood TKR-750 which had been put there as a temporary measure.

David collected Jan at 06:45 and Paul at 07:15.  The team reached the site at around 09:30.  The Tait was re-installed and the Kenwood removed, but despite introducing a bandpass filter to the receive path, the Tait’s front-end was not suited to the high noise on the site.

Consequently, the Kenwood was returned to service.  The bandpass filter was left in place.

Photo: ZS1DDK

Hermanus maintenance 20170212

David (ZS1DDK), Jan (ZS1VDV) went to do some maintenance on the Hermanus repeater.

With the last installation of the repeater it was found that the repeater rf sensitivity was not what was expected and needed to be corrected.

The weather was on and off with rain, the same as installation day, which did not make it fun.

Rain, not fun.

Started 06:30 in Bellville.
Pickup and pack equipment in Stellenbosch 07:15

Equipment packed

Left Strand around 08:00
Arrived on site 09:15.
Debug repeater sensitivity. In the process to realign the front-end, it was found that one of the 4 notch filters tuning pots need to be replaced as it was damaged.
The spare repeater was installed, audio aligned and link controller reconfigured for new repeater.
Did some testing with Sam (ZS1OR). The spare repeater is better, but still some areas need to be looked at.
Left site around 11:30.
Extended the power supply power lead with 2m.
Got some “quick” lunch on the way back.
Unpacked at Stellenbosch 14:30.
Back in Bellville 15:00.

Link Installation Hermanus 20170115

ZS1TAF left home at 07:00. ZS1DDK, ZS1VDV, ZS1V and ZS1OR were collected and all the equipment was loaded in 2 vehicles.

The team arrived on site at about 09:45.



The weather was windy, misty and there was some rain to complicate matters. The team all got stuck in and many of the tasks were executed in parallel.

Raining, ZS1TAF sealing new UHF antenna, ZS1V keeping rain off ZS1VDV tuning the duplexer

The first step was to confirm the correct SWR on the current VHF installation.  This was found to be an acceptable 1.2:1.

The previous repeater was removed and the hut cleaned out.  A Webb HD400 UHF dipole, fed by half inch Heliax and an LMR400 patch lead, was installed with lightning protection, for the link to Hanskop some 40km away.

ZS1TAF sealing the UHF antenna with ZS1OR

The duplexer was retuned which improved the insertion loss from 3 dB to 1.5 dB, and the rejection from 65 dB to 82 dB).

145.725 duplexer results after tuning by ZS1VDV

The UHF power output was measured at 2W and SWR on the antenna system after installation at 1.1:1.

As with many of the WCRWG repeater installations, the new link controller installation includes inside and outside temperature sensors as well as a DC voltmeter that can be queried by sending DTMF codes.

The repeater power output was measured at 10w after the duplexer.  Due to local noise levels, the squelch of the repeater had to be tightened somewhat.

The team left the site at about 13:00 and everybody was back home with the vehicles unloaded by around 16:00.