Yaesu ATAS 120 Antenna Fixed (for now)

With a trip coming up this weekend and it being ham radio’s field day, I decided it’s time to take the second attempt at fixing my ATAS 120 automatic HF mobile antenna. Last time I took the base off and cleaned some corrosion out of it reseated some grounding screws and tried it. It worked slightly better but was still getting inconsistent SWR on 30m and 40m. Sitting still I’d tune it then with a slight breeze (or not) suddenly it’d be 10:1. Occasionally it wouldn’t even tune on 40m. Of course the first thing you check with any HF issue is grounding, but everything was intact I even improved a few ground points replacing old braid that had been in place for ever. Still no luck.

Last night I pulled the ATAS off my truck and in the house for major surgery. I disassembled the thing into as many parts as possible, cleaned everything and started reassembly.
As I put the thing back together I checked everything for any anomaly. I cleaned the circuit board on the base; retwisted the power leads on the motor and cleaned the coil. Cleaned bit of corrosion off of several screws and connections. Finally as had everything almost back together I decided to tighten the metal clips that hold the ball bearings against the coils. I took each clip off bent it slightly to put more pressure on the bearing and put the clip back on. (I think this may have had more effect than anything.

I’ve got the thing back on my truck and will finish redoing my after market water proofing tonight. But I’ve done sweeps on every band and it seems to be fixed. The unit will easily tune any band and once tuned I can drive down at 65mph, putting out 100 CW and the SWR needle barely moves.

Lets just hope it stays this way for a while, if not, that Tarheel 100 will look great on my truck.

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