[Flexradio] 1 KHz tone on SSB

[Charles Greene]

Hi,

I have a 1 KHz tone on my signal when transmitting SSB. The 1KHz 
signal is about 20 dB over the noise level at that frequency.   It 
does not occur when using VAC, and it does not occur when I key using 
MOX with no mike is plugged in.  I am using a  Firebox.   When I plug 
a mike into the SDR box with a cable from the SDR box to the mike in 
on the Firebox, I get the tone when I press the PTT.  When I unplug 
the cable from the SDR box to the mike in on the Firebox, and plug in 
a different mike into the Firebox, I get the tone again, but it is 
only 10 dB over the noise level at that frequency.    Set the RF 
power to 1 watt; no change.  The tone is very stable, not like RF 
feed back.  There is no test in progress.  Restart everything, no 
change.  Nothing seems unusual in the Firebox setup.  Any one have 
any suggestions?

73,  Chas, W1CG