Flex 3000 shuts down on transmit

frankcox

My 3000 has a problem that recently cropped up. When transmitting on 20 meters the radio immediately shuts down. No problem on 10 meters. I have separate antennas for those bands and do not transmit on any other bands. I use a separate tuner, MFJ Versa II. The MFJ shows no reflected power and swr is below 1.1:1 Running the ATU in the radio shows a 1.6:1 swr. I did some maintenance on the 20 meter antenna just before the problem started so I strongly think that is the problem but cannot figure the problem out. I built a 20 meter vertical ground plane that sits on a masonry block a few inches above ground level with radials spread out buried about an inch deep. I replaced the radials as they had mostly corroded away and checked the connections both to the radials and to the antenna radiator. I am stumped. Any ideas? I've used this antenna for years with no problems.

Mike-VA3MW

I would test this on a Dummy load first and see if the problem still exists.

frankcox

Mike, thanks for the reply. I think I just got it fixed. When I replaced the ground radials the yard and ground was extremely dry, so much so I could barely get a short length of wire in the ground before the dirt would just fill in the trench. I put just enough wire in the ground at the outer ends just to keep them in the ground. Problem was the exposed wire above ground kept wanting to coil and loop. I just now finished getting it all below ground nice and straight. Got all the over length trimmed and double checked it all. Then I started the sprinklers to get some moisture in the ground. The immediate result I'm seeing is my background noise level has dropped drastically. Right now my background noise level is an s2. That is the lowest I have ever seen it in this town. No problems with xmitting 20 meters, clean 1.3:1 swr. Receive is as clean as it's ever been. Still looking to make a QSO and get a signal report.