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How to set the bandspread to neatly match a given ham band

Posted: Tue Nov 01, 2016 9:04 am
by jon
We had the question recently from an SDRuno user who asked the question: "How can I set the bandspread such that it covers exactly the 40m amateur band?"

This was our answer:

There are two ways to the frequency span that you want (or close to it). It may not always be possible to get the exact span, but you should be able to get reasonably close. The displayed frequency span is determined by the final sample rate used by SDRuno. If you open up the advanced tuner settings panel (ADV) from the main panel, you will see the Final SR at the lower left hand corner of the ADV window. It is also displayed in the top right hand corner of the Main Panel.

Now, firstly, ensure you are in Zero IF mode. Next select the closest IF BW value that is lower than the final span that you want (it must be lower than). Now select an RSP SR (ADC sample rate) of 2.8 (2.8 MHz) and a Decimation factor (DEC) of 8. You will now see a FINAL SR of 0.35 MHz displayed. With this method and in this case, you will see some slight roll off at the band edges. This is because the closest IF filter bandwidth to the desired frequency span is 300 kHz and the IF filter will slightly attenuate the edges of the spectrum relative to the centre. It will not affect your ability to receive signals at the edges of the displayed window.

Now, open the Receiver window by pressing Rx in the Main panel. Now click on the frequency display with your mouse and type in your desired centre frequency and hit the enter key. Open up the SP1 display and you will not see the 40m band displayed with a span of 350 kHz.

A simpler way (but less accurate) is simply to type your desired frequency span in the BW window in on the Main panel. This is a quick frequency span setting window. If you type 0.35 into the BW window, you will see the Final SR change to 0.3. This is because the software tries to pick the closest available tuner IF bandwidth first (which in this case is 300 kHz) and then set the sample rate that is appropriate for the IF bandwidth, so in this case, you will not get the full desired 350 kHz display.

Jon, SDRplay

Re: How to set the bandspread to neatly match a given ham band

Posted: Tue May 23, 2017 4:00 pm
by w1ksz
There is no BW window in my Main Panel. I am using Ver 1.13.

Anything else I can do to change the BW ?

Tnx, Dick, W1KSZ

Re: How to set the bandspread to neatly match a given ham band

Posted: Tue May 23, 2017 6:44 pm
by Paul
A perhaps simple question.
I have been happily operating my RSP2 using SDRUno for a while now and have struggled a bit with creating set frequency bands.
Having read this guidance, it would seem to offer a reasonable solution for me. However search as I might, I cannot find the ADV tab to enter advanced settings.
Can you offer advice please.

Re: How to set the bandspread to neatly match a given ham band

Posted: Sun May 28, 2017 8:59 am
by octave9
Jon's original post was around the time of significant changes to the software, judging by the Release Notes, but they don't provide much of a clue.

"RSP advanced window" was mentioned in the Version 1.03 (18 th September 2016) updates, but must have been removed for Version 1.1 (11 th November 2016). I didn't have mine then, but would have thought such a significant change would have been explained, or at least mentioned.

Would be good if Jon (or anyone) could update us on how to set the IF bandwidth in the 1.13 version.

Re: How to set the bandspread to neatly match a given ham band

Posted: Fri Jun 02, 2017 11:09 am
by pgoelz
I can get close enough to the desired waterfall bandwidth that I want by simply using the zoom buttons. However, it would be HIGHLY desirable if this zoom level (and also the LO frequency) were stored along with the other items that are stored in the memory panel so they could be easily recalled.

Paul

Re: How to set the bandspread to neatly match a given ham band

Posted: Fri Jun 02, 2017 3:25 pm
by w1ksz
The problem was neatly solved by just changing programs.

I installed SDR Console and find it does what I want so SDR Uno is no longer with us !!

73, Dick, W1KSZ