[Yaesu] FT-900 with 'motorboat' audio on SSB

[Augie Hansen]

David Willmore wrote:
>> ...
>> When I put a receiver
>> next to it, and transmit in SSB, I have an odd modulation on top of my
>> voice.  
>> ...
>> Further playing shows that the modulation *does happen in all modes*,
>> including FM and AM--earlier tests were in err.
>>
>> Time to crack it open and start poking around.

Before you poke around inside check the power supply voltage at the rig 
under full load. If it falls below about 12.5 vdc the FT-900 will likely 
start "FMing" in all transmission modes. If it's low you'll need to 
improve the source of power, the wiring, the connections, or all of 
these to keep the rig's frequency determining circuits from wandering in 
response to modulation.

Good luck.
Gus Hansen
KB0YH