SDRplay Community Forum

I have EXT IO 3.8 and notice a bug with PROFILES.

The EXT IO pane can correctly adjust the gain reduction when the LNA is switched ON/OFF so that the total GR stays the same. However if I store a pair of PROFILEs, One with LNA ON and the other with it OFF, otherwise identical, then switch between them, when I select the Profile with LNA ON although the GR shown is correct in the EXT IO pane, the GR does not actually take effect, the receiver gain is increased by the LNA gain of 24dB. Toggling the LNA OFF and then ON again sorts it.

So in summary the Profile appears to cosmetically store the GR with the LNA ON, but in reality it doesn't.

Hi,

I can't reproduce this. If you load up the 2 profiles I've attached to this post, the only difference is that one has LNA on and the other LNA off - If I assign them to P1 and P2 and hot swap between them I can see the LNA toggle on/off

If you can send the .rsp files you've created to support@sdrplay.com I'll be able to take a closer look.

Are you using profiles created in v3.8 or an earlier version?

Best regards,

SDRplay Support

I am using one profile created by earlier version and the new one with v3.8, so let me delete that and try again with a fresh one.

The profiles you created have the AGC ON.Try it with that off and I think you will see what I see.
I will email my profiles shortly.
Thanks.

Hi,

I'm a bit confused. I loaded up the profiles you sent me and when I toggle between them, the lna toggles on/off and the IF gain reduction changes by 24dB and the overall system gain reduction stays the same. This is how the system is designed. The original version of the LNA on/off switch added the LNA gain reduction step to the overall gain reduction value, but it was decided that it was better to maintain the overall gain reduction and adjust the IF gain reduction to accommodate the LNA gain reduction step.

Best regards,

SDRplay Support

I think you are missing the point of what I am reporting, perhaps I am not explaining it well enough, sorry.

The profiles do indeed -appear- to work as you describe on the EXTIO pane, but if you use HDSDR and toggle between the two profiles, the one with the LNA off (which shows that same figure for overall gain quite correctly) gives an extra 24dB gain to the noise level of the receiver etc because the LNA isn't actually off I presume. If I then manually toggle the LNA on and off again then the correct gain level returns to HDSDR.

Hope that you can see what I mean.

Thanks again.

Oh, the noise floor changes when you toggle the profiles. So the values are correct, but the waveform is wrong. It's like something is being loaded in the wrong order.

I'll have to investigate, sorry for not getting that the first time.

Best regards,

SDRplay Support

Thanks, I am sometimes struggling to explain things in the best way. I was almost at the point of making a video to show the problem.

Regards.