So an update on my antenna. It appears the center pin of the AT-197/GR got pushed in further inward. This might be due to previous users not realizing this has an HN connector and forcing other connectors like an N to it. This is a common problem buying these used antennas with this problem or missing radials. I bought one 20 years ago and it was dead. Back then I did not have the troubleshooting skills and just kept the antenna in the garage.
When I use the HN to N adapter the center pins was not making contact and hence the dead antenna. When I check for continuity without the adapter everything reads good. With adapter on the center pins was not making contact. I bought an expensive adapter, they run $60-100. Adapter was checked and read good for continuity. I therefore realize the problem was the antenna.
I took the antenna apart since I had nothing to loose and the first thing was that I noticed was lots of corrosion and rust. I ordered a rust cleaner and it will arrive next day.
As per someone in one of the threads about At197/GR there is no lightening arrestor. Just getting continuity from the top radials to the center pins without the adapter, alerted me to the fact there is no lightening arrestor, but I still tore the antenna apart to clean it. From the top radial there is a very rigid large diameter coaxial RG 17A/U rated for 11000 volts that runs down to the HN connector, and a rigid tubing use to support the mast. The antenna can transmit up to 1000 watts continuous power hence the heavy rigid cable and the HN connector which is larger than an N connector.
I was able to disassemble and push the center pin outward, attached adapter and checked for continuity, and it was a go. I then used some LMR 195, about 20 ft to my Airspy and checked the two ground ATC here in WPB 270.325 low milcom band and 353.600 high milcom band and reception was about +2 dB better than my OmniX, Sirio 2000, TACO D2214 Muldipol 225-400 Mhz antenna.
