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my problem with ..uno

Posted: Tue Oct 02, 2018 12:44 am
by dlritter
It does not filter out CTCSS tones from FM/NFM signals making it a bit annoying to monitor the local PD, SO and Fire dispatch ckts.
So SDR# to the rescue.. Filter Audio (ON)

OR am I missing something?

73 Dave N6DL

Re: my problem with ..uno

Posted: Tue Oct 02, 2018 9:26 pm
by NoelC
Try the PDBPF button near the bottom of the EX CONTROL window.

-Noel

Re: my problem with ..uno

Posted: Wed Oct 03, 2018 12:59 pm
by g1hbe
It's buried on page 25 of the manual, just above section 7. It'd help if it was called 'audio filter'.

Re: my problem with ..uno

Posted: Wed Oct 03, 2018 9:13 pm
by dlritter
found it, thank you.

Re: my problem with ..uno

Posted: Wed Jul 17, 2019 7:13 pm
by Mr. Lucid
I was monitoring a net last night on our local repeater and noticed hum on the repeater audio. My initial suspicion was that I was hearing the 103.5hz "sub-audible" CTCSS tone that is emitted on the repeater output. Digging around online, I found my suspicion to be correct. There is a great YouTube video using PowerSDR demonstrating the presence of and subsequent filtering out of this tell-tale sound:
https://youtu.be/JzQVPKUyWjg

In PowerSDR this is controlled by the "TNF" function and in reading this thread I assume SDRUno's equivalent feature is the PDBPF button. I'll admit, I haven't tried it yet, but I will as soon as I get home.

In searching the SDRUno manual PDBPF is listed as the "Pure Data Band Pass Filter" and goes no further in detail. Having an inquisitive mind, I'm curious to know if someone could elaborate a bit more on the meaning and function of this button.

Thanks!

-Chris

Re: my problem with ..uno

Posted: Thu Jul 18, 2019 1:41 am
by Mike2459
From what I can tell by viewing the audio spectrum with PDBPF filter on and off. It acts as a low-pass filter with a cut off around 8 kHz

Re: my problem with ..uno

Posted: Fri Jul 19, 2019 9:42 pm
by mikeladd
I believe the PDBPF is a band-pass filter with the cutoffs assigned via the LC (lowcut) and HC (highcut) values in the EX CONTROL panel.
https://imgur.com/a/4iGnFjS

Re: my problem with ..uno

Posted: Sun Jul 21, 2019 12:46 am
by Mr. Lucid
Ah... Yes, it's a lot clearer now having played around with that setting. And it also makes sense to use this setting to eliminate CTCSS hum on your receive audio. "Pure Data" still seems an odd way of describing a band-pass filer assigned to audio range cut-offs. Thank you for your replies!

-Chris

Re: my problem with ..uno

Posted: Sun Jul 21, 2019 7:31 am
by g1hbe
It always used to be called the 'Post Detection Band Pass Filter', I can't recall when it changed. I leave it on all the time.