[Elecraft] Passband tuning

Thu May 9 18:28:00 2002

Lyle,

From what you are saying about passband tuning, I can see no problem in
implementing it in the K2 hardware as it is today. I would think that
moving the main oscillator and the BFO in sync in opposite directions
could be done in software. So we'll ask for it to be put on the wish
list for ver 3.0 of the software!

Sverre 

-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Lyle Johnson
> > > And it would make passband tuning a breeze :-)
>
> > Doesn't this require a dual-conversion receiver where the second 
> > oscillator is offset from its normal frequency?

> No, you just move the HFO the same amount, but in the opposite
direction, as you move the BFO.  
> The net result is that the receiver stays tuned to the same incoming
frequency, but the passband 
> is shifted. No extra conversion necessary.  And with the CPU
controlling both oscillators 
> precisely, it would work quite well.  As has been pointed out, you can
do this crudely by setting > up more filter positions in the K2 to
achieve the same end - but then you lose the ability to 
> select a narrower filter...