[Elecraft] K2 PSK TX/RX offset problem solved

[Julian (G4ILO)]

For those of you who use the fabulous MixW program for data modes, I think
I have come up with a solution for the well-known problem of the K2's
receiver changing frequency slightly when a narrow filter is engaged. The
solution is basically to always use a macro to switch in the narrow filter,
(using a CAT command) and to include in this command a MixW command to lock
the TX frequency so that it doesn't change when MixW's AFC tracks the
frequency change that it sees on the received signal.

The macros I use are:

Select Narrow (Gray -): <LOCKTX><CATCMD:FW00002;>
Select Wide (Gray +): <UNLOCKTX><CATCMD:FW00001;>
Center Signal (Gray *): <UNLOCKTX><CATCMD:FW00001;><ALIGN:1200>
Seek Right (<<): <UNLOCKTX><CATCMD:FW00001;><SEEKRIGHT>
Seek Left (>>): <UNLOCKTX><CATCMD:FW00001;><SEEKLEFT>

AFC and SNAP are always ON in my configuration (I'm not entirely sure of
the difference between AFC and SNAP, so I'm not sure if this is right, but
it doesn't seem to do any harm.)

In all the macros that change the frequency, you'll notice that as well as
unlocking the TX frequency I also select the standard filter again, so as
not to inadvertently start receiving another station with a TX/RX frequency
offset.

I haven't noticed any problems since I started using these macros, but I'd
be interested in comments from other MixW users.

On a related topic I'd like to pass on a tip I saw in another forum: the
program QuickMix from www.msaxon.com. This free program can save mixer
settings and restore them from the command line. So you can run it
automatically when MixW starts up (using the OnStartMixW macro) and have
your mixer settings automatically set to the optimum positions.

Happy warbling.
--
Julian, G4ILO. (K2 #392)
Homepage: http://www.qsl.net/g4ilo