RSP1A vs RSP2 internal noise

[Sasan]

Hey
I was playing around with SDRPlay today and noticed something that wanted to share with you.


1- It seems there is an internal noise/signal at around 2.48MHZ and all its harmonics (4.96MHZ, 7.5 MHZ, 9.97MHZ, etc). These frequencies may drift over time. This is observed on both RSP1A and RSP2. Changing from Zero-IF to other IF modes changes this frequency. It should not be related to the internal 24MHZ clock I guess.

The noise:



2- RSP2 seems to have much more noise (even when not connected to an external antenna). RSP1A has much cleaner spectrum in comparison.

RSP1A without external antenna:



RSP2 without external antenna:




Does anyone have similar issues?
These tests are done in similar conditions (same OS, software, cable and antenna + automatic gain)

[g1hbe]

This thread may be of interest:

https://www.sdrplay.com/community/viewt ... f=5&t=2727

[Sasan]

This thread may be of interest:

https://www.sdrplay.com/community/viewt ... f=5&t=2727

Thank you for pointing out; I should have checked that earlier;
Checking that thread revealed another problem for me (which I will follow up in that thread): I have only one recurring spur on RSP1A, but two on RSP2 !!

[Sasan]

Update:

1- I will follow up the spurs issue on the other thread to prevent duplicates on the forum.
2- As per the internal noise on RSP2, the situation will be much better with manual gain (though I was and am curious why with automatic gain and similar settings, RSP2 and RSP1A show different noise levels)