CTARC QO100 Satellite Frequency Calculator

Our Remote Station at Morningstar has a UHF transceiver and dish antenna that can reach the QO100 geostationary ham satellite, enabling QSOs with many hams worldwide who also can reach it.

Peter ZS1PT has devised a handy calculator spreadsheet to work out where to transmit on the QO100 transponder input and where it will output on the other frequency. He has kindly made it available to the CTARC. Thank you, Peter!

Download the spreadsheet [here].

The file is also available on the CTARC Website's Downloads Page.

CTARC ZS1TA & ZD7GWM Set New 70cm Distance Record - 16 Oct '20

In the SARL morning news bulletin of Sunday 18 October, we learned via Paul ZS6NK that a new South African 70 cm band long-distance record has been set.

 

On Friday evening 16 October 2020, at 18h06 UTC, CTARC member Tom ZS1TA in locator JF95EX (in the Cape Peninsula) contacted Gary ZD7GWM in locator IH74DB (on St Helena Island) on 70 cm FM. The distance between the two stations is 3 136,7 km. 

 

Very well done, Tom and Gary!

 

 

CTARC Homebrew VHF/UHF Moxon Antenna - Oct '19

Here is a link to what looks like a most interesting VHF/UHF Moxon Satellite beam antenna, described by PY4ZBZ:

https://www.qsl.net/py4zbz/antenas/ms.htm

The web page is not in English, however the dimensions are construction are straightforward and should be easily interpreted.

OM Lem ZS1LEM  built the version with 5 UHF elements and 2 VHF elements.

The components include:

• 3.2 mm aluminum welding rods are available from any welding supplier (Afrox etc).
• A piece of PVC pipe;
• A 3.2mm drill bit,
• A piece of RG-58 coax, and
• A coax plug.

It looks like an easy build.

Many thanks to OM Lem ZS1LEM for passing on the link, and obrigado to PY4ZBZ and PQ2HX for publishing the information online.

Photo copyright Hermes PQ2HX

Report-back on Repeater Work Party of 21 Mar '19

On the public holiday of  Thursday 21 March 2019 several CTARC members gathered at the club’s repeater site to form a work party to repair the UHF repeater and mount the UHF antenna onto I.R. Pope’s new tower. The UHF antenna has been mounted on the wall of the repeater building below roof level since the previous tower had blown down in the major storm of June 2016.

The back-up batteries were cleaned and a spare cable was identified and readied to be installed up the tower leg to mount the UHF antenna underneath our existing VHF antenna. Upon inspection, Paul ZS1S discovered that the cable connecting our VHF antenna to its antenna had never been waterproofed! Paul checked the connection and installed the waterproofing. Unfortunately, before he could install the UHF antenna, the wind picked up making further tower work unsafe and he had to come down.

While we were there we also checked the SWR on the VHF antenna and found it to be extremely high. Using his antenna analyser, Peter ZS1PGC discovered there was a very bad connection within the repeater building. Upon inspection we found a badly corroded connection and repaired it. The SWR was now excellent and the repeater works much better than before.

I would like to thank Lem ZS1LEM, Paul ZS1S, Dave ZS1SG, Peter ZS1PGC and Keverne ZS1ABU for coming up the hill and assisting that day. We still need to get our UHF antenna up on the tower and planning is in progress for that.

Addendum:

Following on from this work party, this yesterday Mike ZS1TAF, Peter ZS1PGC and Paul ZS1F put our UHF antenna back on the repeater tower and it is now working fantastically. Now that our Force 12 beam, the new rotatable 40-metre dipole and the tower at the club have all be repaired, all of our equipment is back in perfect working order. What a relief! No more freak June storms please...

Rob ZS1SA