[Elecraft] ksb2 tx/rx alignment

[Don Wilhelm]

Neil,

Before you look too hard at the voltages, try another chance at setting the
reference oscillator (C22 on the control board) right on 4 MHz - there are
several ways of doing that - I have a well calibrated counter, and I use the
K2 internal frequency counter probe connected to TP1, K2 set to CAL FCTR,
also connect the external counter to TP1, then tweek C22 until both counters
agree.  Since the K2 display is limited to display of only the 10 Hz digit,
it will get you within +/- 10 Hz.  Another good way is to use an external
receiver to listen to the beat of the internal 4 MHz oscillator's 5th
harmonic with 20 MHz WWV - that can get you even closer than the external
counter if you are careful and can hear 20 MHz WWV (I am sometimes having
trouble here with the fall of the sunspot cycle).  You can also do it by
listening to 10 MHz WWV, see how much it is off, adjust C22 to compensate,
run CAL PLL and try again - this will get you really close, but it takes
several interations to get it right.

Right after you have the 4 MHz oscillator set - run CAL PLL to plant the
proper numbers into the K2 VFO memory and the dial calibration should be
very close.

You also may have the filter/BFO relationship set not quite right - try
going through it again with Spectrogram and a wideband noise generator
setting the center of the filter passband at the same pitch as you have
chosen for the sidetone.

After doing all that work, I would wager that your dial readings are very
close to where they should be.

73,
Don W3FPR

----- Original Message -----

i would like to say that #3637 is alive and well     but i cant the tx and
rx frequency are off by 300hz and no amount of tweaking has any efect on the
problem
i have done a search on the list (it solved all my other problems) and have
seen some posts about the same fault but i cannot find a cure


all voltages on rx seem to be correct exept u5-5 6.0v
                                                               u4-3 6.0v

have not tried tx votages as yet