[Elecraft] p3 Tap to QSY in Data A mode

[Richard Ferch]

Jim,

I don't have a P3, so cannot comment directly on that aspect, but there 
seems to be some confusion between DATA A and AFSK A in your latest 
e-mail, which may obscure your message.

The mode normally used for PSK and other sound card digital modes is 
DATA A. DATA A is an upper sideband mode, and the K3's dial reads the 
suppressed carrier (BFO) frequency, exactly the same as in USB mode. The 
centre of the filter passband in DATA A is 1500 Hz above the dial 
frequency (1500 Hz below in DATA A-REV). If you were referring to DATA 
A, not AFSK A, your comment about a 1500 Hz offset needed for clicking 
and tuning to a narrow-band signal like PSK31 could be apropos, i.e. 
ideally, clicking on a PSK signal trace in the waterfall when the radio 
was in DATA A mode would tune the radio to a dial frequency that was 
1500 Hz below the actual frequency of the signal being clicked on.

AFSK A is different from DATA A. In AFSK A and FSK D, the K3's dial 
frequency displays the RTTY Mark frequency, which is set by the PITCH 
setting to one of four possible offsets below the suppressed carrier: 
915 Hz, 1275 Hz, 1445 Hz or 2125 Hz. The centre of the filter passband 
in AFSK A is 85 Hz below the K3's dial frequency. If the intent is to 
tune to an RTTY signal by clicking on the upper (mark) trace in the 
waterfall, no offset is needed; if the intent is to tune to the signal 
by clicking halfway between the mark and space traces, then an 85 Hz 
offset would be needed, i.e. the K3 should be tuned 85 Hz above the 
actual frequency that was clicked on in order to centre the signal in 
the passband.

73,
Rich VE3KI


M0CKE wrote:

> Not in PSK D mode as we were running PSK65 so in AFSK A mode
>
> So if it has an offset programmed in for PSK D mode then maybe AFSK A mode
> has been an oversight
>
> Anyone at Elecraft care to comment, I think AFSK A mode needs an offset of
> 1500hz in the P3 so you click and tune to the centre of the pass band, as
> per CW, and PSK D mode.