[Elecraft] K2 drifting?

[Rich Lentz]

The RTTY or Digital filters are available on the newer versions of
"firmware" and allow a complete set of filters tuned and setup specifically
for RTTY or digital modes, however they must be enabled.  The manual
explains this Or if you have an older K2 with an upgraded MCU then you need
to look at the newer manual.

The major point is that -  1. it is almost impossible to get any of the
narrower filters within 1 Hz of the main (OP1) filter that is used for
transmit in all cases regardless of which filter is selected. 2. The PSK
program will transmit a tone equal to what the PSK program thinks is the
received signal frequency - however, that is off frequency by 1 to as much
as 20/30 Hz. from the actual received frequency when ANY filter is used
other than OP1 because the K2 switches to OP1 in transmit. (The offset can
be observed by tuning in a solid carrier and switching filters.)  3. If the
other Party has AFC turned on then he will now transmit at that new
frequency and thus the drift or actually frequency starts walking up/down
the band.  

If you don't have AFC turned on then you will continue to transmit at the
same frequency, unless you reset the signal to the new frequency. If at
least one of the two parties involved does not have AFC turned on then Drift
is less likely to happen. 

There is a small amount of drift in the K2 (less with the Temp Stabilizing
MOD) from cold start for about 15 - 30 Minutes. Thus the above discussion
assumes that 1. you have the temp stabilizing mod installed and 2. the rig
has been on for about 30 minutes.

Rich


----------

Oh, good point.  I forgot to mention that I was using  FL4 which was 
specifically set up for 1000 Hz center frequency and 700 Hz bandwidth.  

I thought that FL4 was specifically set up for digital modes.  Does that 
mean "other" digital modes like RTTY and that PSK31 should be run with 
OP1 instead? 

Mark, NK8Q