[Elecraft] K2SB -- low xmt audio

[k4zm]

Dave:

The setup of OP1 whiuch has to be selected when you setup your filters will
effect the output greatly.  When you go to Cal Fil and have the freq counter
connected to the test point that is located below the KSB2 circuit board,
you need to select FL1 and them adjust the bandwidth to the OP1 setting.
Then use Spectrogram to set the frequency of the BFO in the passband of the
filter.  I use the 300 and 2100 Hz markers and with a noise genertor
connected to the antenna the program will display the passband of the filter
and you can adjust the bfo freq so that the 300-2100 hz is centered in the
passband of the OP1 filter,   The OP1 filter is the seven pole crystal
filter locaed on the KSB2 circuit board and it is used all the time on
Transmit while in the SSB mode.  If your BFO freq is not centered on this
bandpass much of the rf is being filtered out and the result is low rf
output and the audio sounds pretty bad on a seperate receiver.  The filter
FL1 - FL4 are used only on receive.  They are not in the signal path on
transmit.

73 & Good Luck

Jim Younce K4ZM
K2  SN: 18