[Elecraft] #3479

[Don Wilhelm]

Paul,
Unless you have accurately placed the 4 MHz reference oscillator dead on
frequency prior to running CAL PLL, the frequency readout on your K2 may be
slightly off.  Check the manual for the best method available for your
equipment to set the 4 MHz oscillator on frequency first.

To give you a quick check of the correct setting for the BFOs in
relationship to the SSB filter,
start by setting them as specified in the manual for your xtal frequency
(the number shown on your crystal set).  Then ignore the exact frequency
reading on your Kenwood, but tune it for the clearest sound - then switch to
the opposite sideband without changing the frequency on either the K2 nor
the Kenwood.  If the opposite sideband also sounds clear, you have both the
upper and lower sideband BFOs set properly for your voice and your K2 SSB
filter.

If both sidebands do not sound the same in the above step, you have a bit
more work to do.  I would suggest that you tune the Kenwood a bit higher or
lower until both sidebands do sound the same (although they will both sound
'unnatural').  After doing that, determine whether both sound too bassy or
too 'tinny'.  If they sound too bassy, enter CAL FIL on the K2 and set the
BFOs for the SSB FL1 filter a bit further away from the carrier frequency -
the LSB BFO goes to a lower number and the USB BFO goes to a higher number
(if too 'tinny', then move the BFOs closer to the carrier).  I would suggest
moving only 2 or 3 'notches' at a time - repeat the listening then adjusting
sequence until both the USB and LSB audio is as close to correct as you can
get it.  The K2 has a +/- 10 Hz resolution due to DAC limitations, so if you
get within 20 Hz you are likely as close as you can get.

Once you have the FL1 and BFOs set correctly, then you can look at the
frequency discrepancy and adjust the 4 MHz oscillator (run CAL PLL after
each adjustment) until the frequency agrees with your Kenwood (assuming you
trust the calibration of your Kenwood) - or you can use WWV to serve as your
frequency standard should you chose.

Hope that helps - if I caused confusion, my apologies for the long post.

73,
Don W3FPR


----- Original Message ----- >
> But I do have a Problem - I do not fully comprehend the pass band and
tuning
> aspects and the BFO alignment.
>
> I tune in and listen to a station on the K2.  I look at that frequency
> displayed on the K2 and dial in my Kenwood to the same displayed frequency
> to monitor my audio and transmission.  Well - the audio I hear in the
> Kenwood is garbled slightly.
>
> Example :  K2 display reads 14242.50 and is crystal clear
>  On the Kenwood if I dial in that same frequency 14242.50 and transmit on
> the K2 what I hear in the Kenwood is muffled and slightly garbled.  If I
> change the Kenwood VFO display to 14242.20 it sounds much cleaner and
> clearer (still not perfect because of their being so close to the transmit
> antenna and overload)
>