Problems with the FT-897D/AT-897 Combination

Over the weekend I decided to try out the small amount of spectrum that I have access to in the 10 Meter band as a Technician Class licensee. I ran some feedline down the hallway to the connection for the G5RV my father uses for his TS-140 and IC-703 and connected up to the LDG AT-897 antenna tuner I purchased for the Yeasu FT-897D.

At first everything seemed to work just fine, the AT-897 tuned everything up just fine. After several transmissions, however, the AT-897 would make a clicking noise and the SWR would shoot up too high to continue transmitting. The FT-897D/AT-897 combination is connected to a ground rod outside the window next to my operating position, so RF ground didn't seem to be the problem.

On Monday, I sent a technical request to LDG Electronics via their website, receiving a response from them in a couple of hours even though I had labeled by request non-urgent in nature; Repair Technician James Skaar sent me an email explaining that I was probably picking RF through the DC power cord. A trip to Radio Shack the next morning yielded a couple of large snap-on RF chokes for the DC Power Cord and a couple of smaller ones for the Y-ACC and CAT cables. Putting the chokes on didn't take more than a couple of minutes. Initial testing seems to indicate that the problem is solved, I'll find out for sure once I upgrade to General and do more HF work.

Mac McCormick, KF4LMT
kf4lmt@comcast.net