Page 1 of 1

How Do I Display More Spectrum?

Posted: Sat Apr 13, 2019 4:20 pm
by ve3hls
The data sheet for the RSPDuo says it can "Receive, Monitor and Record up to 10 MHz of spectrum" at a time in single tuner mode. I just spent the better part of the evening going through the manual that came with my SDRUno 1.31 download and I can't find anything on how to do this. Mine won't display any more than approx. 2 MHz at a time.

How do I do this?

Many thanks,

Ken Alexander, VE3HLS

Re: How Do I Display More Spectrum?

Posted: Sat Apr 13, 2019 9:03 pm
by Martien
Hello,

In the main window of SDRuno set IF MODE to ZIF.

A new button should appear with SR (Mhz)

Click on the new button to select the desired spectrum bandwidth.

Best regards,

Martien, PD1G

Re: How Do I Display More Spectrum?

Posted: Sat Apr 13, 2019 9:34 pm
by sdrom33
Go to the decimation DEC window if you are in LIF & set it at 1 or, if you are in ZIF set SR window to 10 & DEC window to 1: you will get the 10 MHz, but beware your PC is powerful enough and your RAM at least 4 gb, otherwise audio will start stuttering and finally SDRuno will crash.

Re: How Do I Display More Spectrum?

Posted: Sun Apr 14, 2019 2:11 pm
by ve3hls
Many Thanks to Martien and sdrom33!

I have it figured out now. HOWEVER, clicking that ZIF/LIF button triggers some bizarre behaviour. (Gee, I hope I can attach some images!)

1. ZIF Mode. Listening to MW on 1098 kHz. First image. Note the frequency scale, the freq listed and IF freq below it.
2. Click to change to LIF Mode. Stations stay where they were on Spectrum and waterfall, frequency display is still OK, but freq scale has been shifted for no reason that I can see. The station originally on 1098 is now on the IF freq, according to the frequency scale, which shifts when you change to LIF Mode.

Not only that, but you can't tune any of the stations any more by clicking on the spectrum when in SAM (DSB) mode. It tunes OK in AM mode but you get nothing but screaching in SAM mode.

Clicking back to ZIF Mode sort of corrects this. You have to click the VFO button to re-center things ion the display.

73,

Ken Alexander, VE3HLS

Re: How Do I Display More Spectrum?

Posted: Sun Apr 14, 2019 2:42 pm
by sdrom33
Look at LO lock: if you click on it the pointer will move when you tune. If you click again, the scale will move.

Re: How Do I Display More Spectrum?

Posted: Sun Apr 14, 2019 2:51 pm
by sdrom33
Look at LO lock: if you click on it the pointer will move when you tune. If you click again, the scale will move. You are receiving a very strong signal @ 1153 KHz which maybe overloads the system & causes many birdies, it appears. Also I do not see the S meter bar & the power meter indicator, very strange.

Re: How Do I Display More Spectrum?

Posted: Wed Apr 17, 2019 10:59 pm
by DaveB
You need to be aware of two things regarding the 'full 10 MHz'.

1. The ADC is only running 8-bit resolution. This is going to degrade weak signal quality compared to the 12-bit resolution at 8 MHz.
2. The usable bandwidth (at any sample rate) is 10% less - so you will get around 9 MHz bandwidth at 10 mbps. You can see 10MHz, but you should notice that the outer 0.5 MHz is devoid of signals. (Try it in the middle of the FM band and watch a strong signal disappear before it reaches the edge of the display).

David

Re: How Do I Display More Spectrum?

Posted: Thu Apr 18, 2019 1:25 pm
by ve3hls
Hi sdrom33,

I had the extra S-meter turned off. I always get that blank space when it's turned off. I don't know why. I turned it back on and noticed the SNR display under the S-meter. That's a good enough reason to keep it turned on!

Thanks again for your help!

Ken

Re: How Do I Display More Spectrum?

Posted: Thu Apr 18, 2019 1:32 pm
by ve3hls
Hi Dave,

I don't actually need the 10 MHz display. It's just that I was stuck in the 2 MHz display and couldn't find a way out (I don't think it's even covered in the manual...at least I couldn't find it). I was hoping to find a setting narrower than 2 MHz, not wider. I want to record the mediumwave band overnight and the extra bandwidth wastes valuable hard disk resources.

Thanks again for your help!

Ken

DaveB wrote:You need to be aware of two things regarding the 'full 10 MHz'.

1. The ADC is only running 8-bit resolution. This is going to degrade weak signal quality compared to the 12-bit resolution at 8 MHz.
2. The usable bandwidth (at any sample rate) is 10% less - so you will get around 9 MHz bandwidth at 10 mbps. You can see 10MHz, but you should notice that the outer 0.5 MHz is devoid of signals. (Try it in the middle of the FM band and watch a strong signal disappear before it reaches the edge of the display).

David

Re: How Do I Display More Spectrum?

Posted: Thu Apr 18, 2019 2:16 pm
by g1hbe
You can get spans of less than 2 MHz by selecting a 'DEC' of greater than 1. If the SR is set to 2MHz and the DEC to 1, you get (about) 2MHz of spectrum. Increasing the DEC to 2 will give you 1 MHz and DEC 4 will produce 500 KHz. Sorry if this has already been mentioned, but for some reason I'm finding this thread a bit like untangling spaghetti!