Status update

No shocking things have happened since WPX SSB.

Yesterday I decided to play around in the monthly CWops ‘contest’. Which isn’t really a contest but rather a QSO party. In the first part (1100 > 1200 UTC) I made only 21 QSO. Ouch! And only 4 members, the other 17 were joining the fun without being member. Still I wanted to see if the second part (1900 > 2000 UTC) would be better and it was: 55 QSO, mostly USA and almost all members. I did not get out of bed for the third part. It wasn’t too bad and these are 76 QSO that otherwise would not have been made.

Remember I’m out of WARC antenna since December? This is one of those few periods I hate that. I’m at home, wanting to work some DX and I avoid the regular contest bands. I’m always there in contests so when I want to play DX, I try to do it on the WARC bands. I am working on a 3-band wire dipole but the work has been put on hold for other jobs ‘raising an interrupt’, to use the CPU jargon. So last Saturday I quickly put up a 17m sloping dipole from the tower. That’s one of the easiest antennas to make and it takes only one high support. I’ve made a couple of these so I know what to expect.

Except what I see is NOT what I expect. I expect to see a V-shaped SWR plot. Broad or narrow, under or above resonance, but I expect a V-shaped curve. Yet what the display shows is a waird curly plot, NEVER achieving resonance, and swinging up and down a few MHz left and right from 18.100 MHz. I’ve seen that before and it means the antenna is coupling with something else. Changing the length of the antenna does not change the plot. I looked around but didn’t find anything that could be the ‘coupler’.

I did the same exercise on Sunday but with a simple horizontal dipole. Same story. The only thing I could think of was: it couples with the tower. The tower is out 2/3. That means 15m high, add 2 meter for the tube on top and that’s 17m which is 1λ. I don’t see what else it can be? I tried to pull the antenna away from the tower which made the situation better and in the shack, SWR got as low as 1.9:1. Which is way too high for an antenna that can be tuned for 1:1 SWR. I did work Hawaii (I think a new DXCC on 17m) that afternoon on 17m CW… barefoot 🙂

If it is the tower that is keeping the antenna from resonance, then why did the rotary dipole not suffer from it? I think it is because it was on top of the tower and did not ‘see’ the tower. Everything I pull up with rope and pulley is hanging next to the tower and does ‘see’ the tower. I have NO idea on how to solve this. Decouple the tower? How?

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