[Lowfer] SDRplay RSPdx receiver stability

[Garry]

I recently purchased an SDRplay RSPdx receiver. With the latest SDRuno 
control software I've been climbing the steep learning curve to learn 
how to use it. The ability to have >=2 virtual receivers is particularly 
attractive at LF where potentially one could simultaneously monitor 
lowfer, NDBs, DGPS, and Navtex. That is indeed possible but the user 
manual sure doesn't help in that regard (and a number of other aspects).

I have 2 issues with the receiver:

(1) LF reception is full of broadcast-band AM splatter unless I use a 
band-reject filter between my eprobe and the RSPdx. This has never been 
needed with either of my sdr-iq receivers. Even the HDR mode doesn't 
eliminate the splatter.

(2) Applying a 100 kHz GPS-locked signal and running Wolf software to 
measure the audio frequency for calibration purposes results in random 
shifts on the order of 0.01 Hz. My sdr-iq receiver that is externally 
clocked of course has no drift, but even my free-running sdr-iq 
generally stays put to 3 decimal places until many minutes have passed. 
Fortunately Argo waterfalls at QRSS30 are acceptably stable with the 
RSPdx but the drift is so large and erratic that calibration of the 
sound card sampling rate is crude at best.

I wonder what the experiences with other RSPdx users have been?
-- 
73, Garry, K3SIW, EN52ta, Elgin, IL
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