Over a month since my last post – if anyone is reading that is, but lots has happened on the radio front.
I now have a three element yagis for both 4m and 6m on a telescopic pole in the garden. I finished the rotator installation this morning. I only have one feedline at the moment, 35m of LDF4-50, so until I fit a relay I have to dash out, drop the mast and swap over the n-types. Not ideal, but at least I am on the air.
The miniVNA has been amazing to use during this process.
The 6m Moonraker antenna was picked up at a rally for £25. I can tell why – it was rubbish! The miniVNA showed that it was resonant on 48.250MHz. Fine for video, hopeless as TX antenna. A quick nibble of the DE with a plumbers pipe cutter and re-adjustment of the gamma match and it is now on 50.1MHz. I have made a number of QSOs via SpE but I am not confident of the design of this antenna, so I will have to model it to see what it is like. More news later
The 70MHz yagi is a DK7ZB 28opm design that I built two years ago. Martin’s website suggests that you mount an flange co-ax socket on the balun box to attach the feed line. I was rather worried about water ingress with this system so decided to use a flying lead and a cable gland instead. This made grounding the co-ax shield a real pain as the IP66 box I had chosen was a bit too small and made the system rather mechanically weak. Upon reviving the antenna, the balun assembly had shorted and I had to cut it out of the box and build a new one. If I build another DK7ZB design I will follow the instructions more closely or use a bigger box! I see that a couple of people are producing kits of materials for these antennas which makes life much easier as we can only get imperial sized materials in the UK.
Bad news on the radio scouting front as the GB2GP shack is to be demolished this summer. This means the APRS station will be taken out of service in July. I must do something about getting a vertical up at home to provide central London coverage. Perhaps radio will get a new home in the redeveloped Gilwell LID, but I am worried that it is no loner sexy enough. We are currently working out what do with all the equipment as it will need storing. More news as I get it!
Good APRS news is that G5YC is now active during office hours from central London. The RF noise is intense in EC1, but it seems to doing some use gating RF to INET. With a better antenna I am sure I can get better coverage.
I have also built a APRS portable tracker based on an open tracker and an FT-60E. The GPS I bought to go with it doesn’t work so I will have to steal the car based version when I go to Southampton tomorrow to see if it works.
Jobs to do this week are all centred around Region 1HF CW FD which takes place at the weekend. I am providing the full station for G3GHN/p and we will probably do the PW contest at the same time as not all the club can do CW at contest speeds.
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AuthorA few notes on recent radio activity by Steve, M0BPQ. Archives
December 2020
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