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SDRuno automatically resets Zero IF to Low IF on every single band change

Posted: Thu Mar 28, 2019 3:37 am
by Ruben_NB4R
When I am in any band and change the setting from Low IF to Zero IF and then change bands again, SDRuno will change the setting back to Low IF. Is there a place, that I'm not seeing, that will make this change automatic? After I noticed this I purposely went into every band. Set it for Zero IF and it's reset to back Low IF upon switching bands. This is with version 1.3 of SDRuno.

Also I'm getting the garbled audio described in other threads on almost every start of SDRuno. I just change the Low IF setting to Zero IF to clear this up.

Thank You

Re: SDRuno automatically resets Zero IF to Low IF on every single band change

Posted: Thu Mar 28, 2019 4:17 am
by Mike2459
The only time I have experienced garbled audio is:
1) Using the wrong mode

2) Audio and/or RF Gain too high, there are several places in windows audio where audio levels can be set:
a) at sdruno's volume control
b) at the recording input in the windows sound control panel
c) at the volume mixer

3) switching from LowIF to ZeroIF and not tuning off the center spike, never from ZIF to LIF

4) In stereo wide FM mode 192k bandwidth only, if SDRuno's volume is advanced past midway the audio will be distorted.
5) Excessively high RF input from antenna

Re: SDRuno automatically resets Zero IF to Low IF on every single band change

Posted: Fri Mar 29, 2019 3:10 am
by Ruben_NB4R
Mike, thanks for the list. I can say in this case nothing on the list is causing the problem with garbled audio. My real question is why does SDRuno change the software form Zero IF to Low IF on every single band change?

Re: SDRuno automatically resets Zero IF to Low IF on every single band change

Posted: Fri Mar 29, 2019 5:20 am
by Mike2459
What do you mean by band change? Every time a new frequency is manually entered? Or changing the band presets on the keypad?
I've tried to make this happen (IF mode changing to Z-IF from Lo-IF) and I can't reproduce this issue. I must be misunderstanding something here.

I was finally able to see what you mean. I thought the presets at one time operated in Zero-IF on the preset. Anyway, all I can say is the developers chose to set it up this way. Why? You''ll have to ask them.

Re: SDRuno automatically resets Zero IF to Low IF on every single band change

Posted: Fri Mar 29, 2019 7:33 am
by Tech_Support
Low IF is a better option for the band presets for the HF bands and lower as it results in fewer spurious mixing products from the block converter that is used for covering HF. This is explained in the following application note:

https://www.sdrplay.com/docs/SDRplay_Op ... _MW_HF.pdf

Many people mistakenly confuse spurious higher order mixing products with intermodulation. Intermodulation arise from non-linearities, but higher order mixing product do not.

The other advantage of Low IF mode is that it avoids the need to have the LO and VFO separated.

In the next release, we are going to make it easier to toggle between Low IF and Zero IF modes.

Sincerely

Tech_Support

Re: SDRuno automatically resets Zero IF to Low IF on every single band change

Posted: Fri Mar 29, 2019 6:31 pm
by Ruben_NB4R
Thank you Mike and Thank you Tech_Support for your responses. I was just curious as to why this was happening. I was about to uninstall SDRuno and do an install of 1.3 to see if tat didn't happen. I'm glad to know that is normal. You guys have done a great job with SDRuno and keep up the good work. have a wonderful weekend.

Regards
Ruben_NB4R