[Elecraft] ksb2 tx/rx alignment

[Don Wilhelm]

John, Neil and all,

Either of the methods described include 2 variables - the PLL oscillator
frequency and the BFO frequency - and if you are attempting to calibrate
things, that in itself says that neither one can be trusted for accuracy -
in the second method, you will be setting things so that the dial reading is
midway between your BFO points for USB and LSB - it may be better, but still
not necessarily accurate.

What we do know is that the dial reading is not offset for SSB - so using
Spectrogram, one can set the VFO reading to 10000.00 (or other WWV
frequency) and look at the Spectrogram display to determine how many Hz
offset from the tones they are transmitting your receiver audio actually is
(use the WWV info to know whether the tone is 500 or 600 Hz at the time you
are listening).  Adjust the VFO until the tone is displayed at the correct
audio pitch - then note the dial reading, subtact from 10000.00 and you will
know how far off you are and which way.  Then follow the instructions in the
manual under "Frequency Calibration Techniques" (page 99 in my Revision A
manual, yours may differ) - remembering that you adjust in the opposite
direction from your dial error.
WARNING: This is an interative process - meaning that you do it over and
over again until you get it right - running CAL PLL each time.

The methods of using an external frequency counter or beating the reference
oscillator's 5th harmonic on an EXTERNAL receiver against 20 MHz WWV will
set the reference oscillator right on 4 MHz +/- accuracy of the measurement
device) regardless of what other adjustment errors may exist in the K2, so
these methods are much quicker and easier than the interative process of
listening to WWV with the K2 only.  I recommend using the 'listen to WWV'
method only if you do not have an accurate counter or another receiver.

Hope that helps a bit.

73,
Don W3FPR

----- Original Message -----
| I've tried several methods to get my K2 exactly calibrated:
|
| One way is to tune in WWV on CW and use spectrogram to observe the 10
| MHz carrier.  If your sidetone is set to 600 Hz, tune the radio until
| the peak of the carrier is at the 600 Hz marker.  If it doesn't read
| 10.000.00, adjust it using the method in the manual.
|
| Another way is to use your ears and adjust your tuning until the WWV
| tones on USB have the same pitch as on LSB.  Since you can only tune to
| within 10 Hz, you may not get exactly the same pitch, but you can get it
| pretty close.  At that point, note the display frequency and again
| adjust using the standard method in the manual.
|
| Trouble is, I get slightly different results when I use those two
| methods and don't understand why.  But we're not talking 300 Hz
| difference, more like 20-30.  If anybody can explain this to me, I'd be
| interested.  I have a feeling the second method is more accurate, but
| don't know why.
|
|