My set-up for operating is as follows:
Butternut HF-6V vertical
MFJ-989C antenna tuner
DigiPan for PSK-31
MMTTY for RTTY
My problem is that whenever I transmit in PSK-31 on Upper Side Band and MMTTY on Lower Side Band. I use the internal tuner once in a while to bring SWR down flat. The problem is that when I transmit a digital signal several seconds into my transmission my SWR goes up higher and higher till it pegs the meter on the radio and also shows a high SWR on the meter in the tuner. This does NOT happen in any other mode only USB and LSB while using digital modes.
Yesterday I tested each band into a dummy load and my SWR was perfect. Once I put the antenna in line then it starts up again. I have been running this combination for a year now with no trouble but now I can't seem to operate on SSB at all, not even voice.
Any ideas what it might be ?
Should I be looking to send it to kenwood for a check up and possible repair ?
Tnx in advance for your advice.