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



 

 

CTARC Project Loon - 6 May '18

This is an experimental research and development project by formerly Google X. This project is to provide internet access to rural and remote areas. This project uses high-altitude balloons placed in the stratosphere at about 18 Km above sea level.

Two of these balloons have been spotted on an app called "FlightRadar24. (which please Google).

One is about to fly over Cape town in the next few day. As of writing (6 May 2018) at 11h00, balloon Registration N189LB is at an altitude of 57,300 Ft in position Latitude -33.475 and Longitude 13.5493. The track is 104 degrees slightly south of due east. If it continues on it's current track it will pass very close to Cape Town.

It might be possible to bounce VHF or UHF signals off the Mylar balloon material.

There is another balloon which is presently over southern Angola. It's registration is N183LB.

Check out Project Loon on Google and [here and here], and also FlightRadar24 [here].

Hope this is of interest.

73

Hans ZS1HA