You were right. I changed antenna (used a small whip first, now I built a dipole) and now it works again
I have a similar problem with my FT-897, the DTMF-mic just sends noise instead of audio when I increase power to more than 10W.
But there I know HF is the problem. I tried putting a ferrite core on the cable but no change. The antenna is a fishing pole, 5m, grounded
in the balcony railing. The antenna works great, except from the HF..
I don't have much space to mount any other antenna, and I cannot ground it any other way either..
There is no grounded power outlet in my appartment (except from in the bathroom
) so that might be the problem..
73 DE SM7XAS