Don,
I too am hearing the audio in the speaker
during transmission.? I noticed it first when transmitting digital using
FT8, in fact at times the transmitter went into ocillations with the
feedback.?I could not figure out what had changed while using FT8.?I
had installed the on off switch per your original instructions and found with it
off the ocillations and the feedback went away. I usually have the agc turned
off and only have it on when listening to a net with some very strong signals.
After reading several posts on this issue?I went back and tried it again
and sure enough when transmitting voice or FT8 I hear it in my speaker audio
until I turn AGC off.
I have the AGC board
mounted on the back of the RF Gain pot and RG-174 to and from the header on the
uBitx board.?All volume control and mic jacks are RG-174 back to the main
board. Again not a problem for me as I keep the AGC off most of the time, but
interesting.?? I have noticed earlier when having?mike problems
that when transmitting rf does?show?on the scope looking at the?5
volt supply from the Radino. I was using the 5 volt supply to power a mike amp.
I haven't looked at the 12Vsupply.? Your AGC on off?suggestion from an
earlier posted set of installation
instructions?follows.
?
"If you want to add a switch to shut off
the AGC, do so at the audio input.? I would sugest a singlepole
double-throw switch with the connection to C1 at the center, ground to one side,
and the other to the hot side of the volume control.? If power is removed
from this circuit Q2 will not be biased "on" and will reduce signal levels
significantly."
?
Rick
KN4AIE
