[Elecraft] K2 w/KSB CW reverse BFO

[k6se@juno.com]

K6SE wrote:

"An unmodulated carrier on exactly 4000.000 kHz should be heard with a
pitch of 600 Hz when your K2 is tuned to exactly 4000.000 kHz (not to
4000.600 or 3999.400).  If your K2's VFO readout is accurate, it should
read "4.000.00" when that received signal's pitch is 600 Hz, no matter
whether your receiver is on CW or CWR."
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Andy Wallace asked:

"But what frequency does the K2 transmit on, when set that way?"
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K6SE's reply:

If you are receiving a carrier on exactly 4000.000 kHz with a pitch of
600 Hz as outlined above, your transmit frequency will be 4000.000 kHz
(assuming your RIT and XIT are off).
==========
Andy Wallace wrote:

"I set my K1 frequency calibrtion on a separate receiver such that the
display reads the transmit frequency, so I know I am always in-band."
-----
K6SE's reply:

That's a good practice if you're close to the band edge.  I assume that
the K1's VFO readout accuracy is subject to the same problems as the K2
frequency drift with temperature.
==========
Andy Wallace wrote:

"Whether the received freq is then off by the sidetone offset is not as
important to me. K1 is CW only so I don't have to worry about SSB nets --
and even then, I cut my teeth on tube rigs that I had to readjust every
few minutes. It was just a part of ham radio and not a huge hassle."
-----
K6SE's reply:

My discussion was about CW and had nothing to do with alignment of the
SSB filters in the K2.  When a signal on SSB is tuned in and sounds
normal, the K2's transmitter should be close to zero beat with the other
station's frequency.

On CW, being close to zero beat is important because the station you are
calling may be using his receiver's 250 Hz filters and he may not find
you unless he uses his receiver's RIT.  If your frequency is offset by
600 Hz (as you described above), you'll even be outside of his 500 Hz
xtal filter passband.  It is especially irritating to operators during CW
contests when calling stations are not close to zero beat.

If you are just calling another station for a general ragchew type of
QSO, then, as you said, it's not a huge hassle (as long as he finds your
off-frequency signal).  For most stations however, it would be a hassle,
as well as the QSO taking up more bandwidth in our precious spectrum than
necessary.

If you notice that you have to use your RIT on most stations answering
your CQs, that's a good indication that your receive and transmit
frequencies do not coincide while your RIT is off.

73, de Earl, K6SE