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Re: Does SDRuno Software Allow For Continuous Tuning ?

Posted: Sat Feb 17, 2018 11:57 pm
by NoelC
As you change the frequency, do you see the waterfall slide sideways with the red line remaining stationary (i.e., LO not locked)? I can't help but think you've got a setting wrong that's causing the software to behave in a way that's different from what most of us are doing.

Based on the plateau of the base level in the SP display, it's clear that the sensitivity does fall off 20 dB or so near the ends of the displayable range in any mode. But when I change the frequency (with the LO not locked) that plateau stays stationary with window, with the changing range of frequencies moving within it.

The total amount of power does fall off markedly above the MW band. That's not the radio, it's the reality of band assignment.

Maybe you could do some screen grabs illustrating what you're describing and post them here? That would help others to advise you of what they see, vs. what you're seeing.

Edit: I tried to visit the link you posted above, but was met with a sign in prompt.

-Noel

Re: Does SDRuno Software Allow For Continuous Tuning ?

Posted: Sun Feb 18, 2018 8:19 am
by Paul
Thank you for your responses/interest
For me it's not a big deal, more an observation and I only posted my observation in case it was in any way associated with the original post in this thread and perhaps of use to the respected tech folk.
I did provide a link to a Google photos image of a screen grab illustrating the "cliff-edge."
It seems not to have worked - I'll have to find out how to insert an image ina post - I've done it before but forgotten how I did it - see:
https://photos.google.com/search/_tra_/ ... -Tt56szogh

Re: Does SDRuno Software Allow For Continuous Tuning ?

Posted: Sun Feb 18, 2018 9:25 am
by sdrplay
I just tried to look at the link, but got a page not found message.

Re: Does SDRuno Software Allow For Continuous Tuning ?

Posted: Sun Feb 18, 2018 9:41 am
by g1hbe
Paul WB5AGF. If you use the 'band' buttons, the LO will lock at the centre of the chosen band and the sample rate/decimation will be set so the band is framed properly. With the LO locked you cannot tune out of that band.
If you want to tune freely, the LO lock should be OFF. With it off you can tune from almost DC to 2 GHz without making any intervention.

Re: Does SDRuno Software Allow For Continuous Tuning ?

Posted: Sun Feb 18, 2018 10:24 am
by Paul
Well, perhaps googlephotos only allows "authorised" access - sorry about that.
I'll try inserting an image again, when I work out just how to do it.
The link that I posted takes me straight to the image...

Re: Does SDRuno Software Allow For Continuous Tuning ?

Posted: Sun Feb 18, 2018 11:25 am
by Paul
Spectrum - drop-off.jpg
Spectrum - drop-off.jpg (197.48 KiB) Viewed 4482 times
If this works, it's the imge of the spectrum where mouse scroling ceases to tune the receiver (as previously expained (or attempted to).
Appologies forthe previous "Faff."

Re: Does SDRuno Software Allow For Continuous Tuning ?

Posted: Sun Feb 18, 2018 2:16 pm
by sdrplay
You have a sample rate of 2MHz and a decimation of 8 which gives you a total sample rate of 250kHz and the IF bandwidth is set to 200kHz. The LO is set to 342kHz, so you are just seeing the edge of the IF filter rolloff.

Looks normal to me.

Best regards,

SDRplay Support

Re: Does SDRuno Software Allow For Continuous Tuning ?

Posted: Sun Feb 18, 2018 2:18 pm
by sdrplay
Also, please note that port A and B of the RSP2 are only spec'd down to 1.5 MHz - if you want to get good performance at VLF, you are better using the HiZ port.

Best regards,

SDRplay Support

Re: Does SDRuno Software Allow For Continuous Tuning ?

Posted: Sun Feb 18, 2018 4:43 pm
by Paul
Dear Support
Thanks once again for a concise and clear explanation - sorry, I'm still learning - now much wiser.
I do appreciate the difference between the i.5Mhz ratings and the use of the Hi-Z Port, however, Ports A & B do have the advantage of the MW/FM filter, which I suppose will remain out of the question for the Hi-Z Port and at present, my interests are amply satisfied and I am amazed at how well A & B perform below their rated limit.
The RSP and uno are a revelation for me.

Re: Does SDRuno Software Allow For Continuous Tuning ?

Posted: Tue Feb 20, 2018 6:48 am
by WB5AGF
(here is a bit more information)

If I unlock the LO while I have the receiver tuned to an AM station .... and then I begin to tune the receiver the audio from the AM station continues to be heard (showing that the receiver is not actually changing frequency) .... the 'background' RF spectra (all the stations on the AM band) remains fixed in position but the frequency scale at the bottom of the screen begins to move in-sync with my turning the tuning control. The fact that the background spectra does not 'move' (and the audio from the AM station that I was tuned to before beginning the test continues to be heard) shows that the receiver is not actually changing frequency even though the display otherwise makes it look as though the frequency is changing.

(signed)

- Paul, WB5AGF
. Texas