On Saturday the 27 December 2025, Jakobus ZS1JDJ visited his father in law OM Jan ZS1CBS at Heuningklip near Herbertsdale. He carried out some tests from the QTH of Jan to ascertain why Jan ZS1CBS cannot access the 145.625 Mhz Aasvoëlkop Repeater which is situated about 22.8 km away from the farm as the crow flies. Now why would they not be able to access the repeater? I looked into the matter and here is some interesting information that I found. Please note that the data is analyzed as I received it. Slight differences might exist.
- The repeater could not be accessed with 20 Watts RF Power
- Using a 11 element Yagi they were able to open the repeater but the audio was unintelligible. Lots of rain on the carrier signal.
- The topography showed that there are quite a few small mountains around the QTH of ZS1CBS.
- The antenna was tilted upwards and also pointed at the mountains around the QTH (in all directions) to look for a possible reflected signal towards the repeater.
- Topographic images confirm that the QTH is situated between mountains.
- Jan ZS1CBS can however access the 145.650 Riversdale Repeater (See image why.) No mountains in the way. Opening through a valley?
- The "range" of mountains in the way from the QTH to the Aasvoëlkop Repeater is clearly visible in the red circle in the image below as well as the Radio Path Study Image.
- Signal distribution images (Radio Mobile) showing that there is no signal propagation to the Aasvoëlkop Repeater. (No green or yellow reflections. White - No signal distribution)
- Riversdale Repeater signal distribution present. (1 - 10 Micro Volts and more.)
- The Radio Link Study 1 as with regards to the Aasvoëlkop Repeater reflect the fade margin as -5.07 dB and 28.52 dB in respect of the Radio Link Study 2 aka Riversdale Repeater. Significant difference!
Comment: With the "ground work" now done it is clear that Jan ZS1CBS has currently better access to the Riversdale Repeater than the Aasvoëlkop Repeater. Further tests with different antennas and antenna polarization need to be done. A high power radio (50 Watts) should also be tested.
Conclusion: There are several other options available to "get onto" the Aasvoëlkop Repeater from the QTH and these will be looked at once we are sure that there are no path to the repeater with any VHF Radio equipment.
A big thank you to Jan ZS1CBS, Jakobus ZS1JDJ, Johann ZS1AAC and Viv ZS1VIV for providing the data that enabled me to evaluate the different radio paths as listed below.
Images: (Click on images for larger view.)
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