[Elecraft] Calibration of BFO

[Tom Hammond NØSS]

Dave:

Yep.. you're tight there... I sometimes tend to forget the 'details'... 
thanks for bringing me back to earth. <G>

Tom


At 08:17 AM 2/4/02, Dave Gingrich K9DC wrote:
>At 07:28 2/4/2002 -0600, Tom Hammond NØSS wrote:
>
>>Consider NOT using the OP1 filter for PSK31. You can set the other three=
 
>>filters FL2 thru FL4 to wide mid and narrow bandwidths as well... 
>>possibly, you can find settings which don't shift using strictly the CW 
>>filters.
>
>Only problem is OP1 is always used on transmit so you need to minmize the=
 
>shift between OP1 and the chosen receive filter, even if you never use OP1=
 
>to receive.
>
>>Note that it is NOT at all unusual to have a 10Hz - 20Hz frequency shift=
 
>>when switching between filters. If you managed to get it down to 0Hz 
>>shift, it was almost a fluke.
>
>I have found that you can get the shift reduced to less than 1 Hz by just=
 
>repeating the procedure numerous times. Sometimes by just adjusting one 
>filter at a time.  Often I just go in to the procedure and just the BFO by=
 
>one 'notch' and back again and exit, so it will recalculate the offset.  I=
 
>have been able to get it down to the point where there is no audible pitch=
 
>change (musicians ear) between the filter settings, and just a slight 
>phase twist on the PSK tuning eye.
>
>It WILL drive you nuts, but it can be much better than 10 - 20 Hz.