[Skimmertalk] Skimmer Advice (K3 IF issues)

Pat Rundall pat at n0hr.com
Mon Nov 9 18:26:23 EST 2015

Skimmer Gurus...

I'm looking for a bit of advice on how to improve my setup for CW contests.
Namely, I'd like to avoid the 24khz limit of the k3/LP-Pan setup and issues
with the output shifting frequencies when I change filter settings on the

The Goal:
Aggregate useful skimmer spots -> N1MM+ for the current and adjacent bands.
I'd prefer to have the skimmer running on the active antenna (ie a beam
rather than a short vertical or loop)

The Current Setup

   - N1MM+ on a laptop
   - K3/100 as the main rig w/RX2
   - LP-Pan2 from IF-Output of K3
   - USB sound card capable of 192khz
   - Currently, I'm routing the RX output of the k3, through a
   DX-Engineering RX-Guard and then into the RX input as a means of protecting
   the front end in a SO2R environment (also using BPFs, etc.). (100w)
   - Aggregating spots from a local packet node with wintelnetx

Other HW available

   - Afedri SDR
   - Pixel RX loop

The problem
I noticed in Sweepstakes CW that the Skimmer is only decoding +/-12khz
rather than the whole 192kHz at once. Also noticed that when I change
filter settings on the k3, the frequency jumps on Skimmer. I've read where
both of these issues are known and there really isn't a working solution
apart from simply using other hardware. Unless I've missed it, I don't see
a solution to these issues offered by the vendors (Elecraft/LP-Pan/VE3NEA)


   1. Setup the Afedri SDR to be a standalone receiver by putting a
   splitter after the RX-Guard on the RX-out/in loop. I may see a bit of
   signal loss on that. I'd probably setup the Afedri on a separate PC running
   an SDR app (HDSDR?) with Skimmer. Then when I change bands, manually change
   that on the app. Not horribly inconvenient.
   2. Setup the SDR on the RX loop with another RX Guard. (Even if there is
   a fix to the K3 IF issues, I may setup another SDR on the loop to monitor
   the adjacent band)

Other thoughts?


Pat N0HR

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