Thank you for asking. I sent it to a tech. He has had it running on the bench for a few weeks and no problem has occurred, but something else has surfaced here at home when using my IC-756PRO3 on 6m.
The SWR became very unstable and then the rig went very deaf. My rotating I have a junction box on the antenna mast where the flexible "tails" from the antennas are connected to the main feedlines. It also contains the multiplexer that connects the 6,2 and 70cm antennas to a single feedline. When I opened the box it was filled with an ants nest, with lots of gooy matter and quite damp. The formic acid from the ants had also corroded the connectors.
You make the comment with regard to the FT-847: "VSWR protection seems to shut down the power output without much else obvious." . I think that was the cause of my problem. The repeated closing of the PTT finally made some sort of match and the power increased. The only thing that does not add up for that theory is that the "high SWR" light did not come on. Maybe it is faulty.
I cleaned up the mess, replaced the connectors, and ant-proofed the box and the SWR on the IC-756 is back to normal.
I am not too concerned that the tech has not found anything wrong. The rig needed re-alignment and the memory battery replaced anyway. The main switch was replaced some time ago.
73
Wayne VK4WDM
