Tuesday, March 26, 2019

Uh Oh. Not Good.

Well, if it isn't one thing, it's another. After celebrating getting the A3S/A743 rotating again, I've found a problem. The SWR shifts I mentioned? On a dark night, I went outside and looked up at the antenna while WSJT-X was transmitting on FT8 trying to contact someone. I tried this on 40 and 20m.

I observed one of the 20m traps on the driven element light up with arcing using 100 watts. It was visible in the drain holes and end caps of the trap.

At the very least, I'll need to take the driven element down and rebuild it.

Update: I've tried this experiment on 15m, and I see no SWR shifts even using 500 watts. I think the problem may be confined to the 20m trap(s).

Monday, March 25, 2019

Rotating Again!

Well, it didn't take months after all. As I wrote last month, my A3S/A743 had been stationary since December. But with the beautiful spring weather here in Georgia, I managed to get to the top of the tower and finish the installation.

It's now rotating freely, as expected. It's really good to be able to use the beam as intended, and not have it fixed roughly east.

I do wonder if the A3S/A743 needs repair, however. I'm still seeing occasional SWR shifts at 100 watts on 40 and 20m. I'll need a gin pole to take the antenna down to refurbish.