Re: [Elecraft_K3] K3 IF output, 3 "dumb" questions...

Rudolf Schaffer

Hi Alan,

Thank you for these explanations.

I've remarked that the BW was related to the selected HF band and you gave to me
the "reason" ! The FCDP+ is too "short" to cover the full band and i will look
to use an other SDR with more usable BW; i've some other ones in "stock"
with sufficient BW but not as good as the FCDP+ but maybe sufficient
at the K3 IF, not "directly" connected to the antenna !

As i planned to use IF output, a (very nice) P3 is not necessary because
i'm not "looking visually" the band activity, just "waiting" for a
new call/locator/band/mode/etc.

For the moment, i'm "surveying" only JT65/9 , but i want
to extent this "activity" to other ham digital modes.

My best 73,
Rudi, hb9ari

Le 27.04.2016 19:01, Alan alan@... [Elecraft_K3] a écrit :


Hi Rudi,

On 04/27/2016 06:46 AM, Rudolf Schaffer rudolf.schaffer@...
[Elecraft_K3] wrote:
> Hello,
> I've 2 questions for my K3 (#1212) IF :
> -1- What is the max. BW "usable" for the IF output ?

It is mainly limited by the RF bandpass filters in the K3. Generally
the width of the ham band plus a little.

> -2- What is the "relation" between VFO and IF frequencies ?
> -3- Is this relation "constant" between HF bands ?

The IF is 8.215 MHz, plus or minus a little depending on the mode and
crystal filter in use. The local oscillator is 8.215 MHz above the RF
frequency on 10 meters and 8.215 MHz below the RF frequency on 6 meters.
So the IF passband is inverted on all bands except 6 meters.

For transverters, the IF is not inverted if the transverter uses a 6
meter IF and inverted if any other IF is used.

Of course, the P3 takes all that into account automatically.



> Thank you for your help.
> 73 QRO,
> Rudi, HB9ARI
> ------------------------------------
> Posted by: Rudolf Schaffer
> ------------------------------------
> ------------------------------------
> Yahoo Groups Links

Join to automatically receive all group messages.