"Pulsing" Analog Audio?

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PeterGV
Posts: 76
Joined: Sun Nov 25, 2007 8:30 am

"Pulsing" Analog Audio?

Post by PeterGV »

I'm hoping somebody here can give me a clue about what might be causing this.

I've got a VHF XTS-5000 that *sometimes* has a "pulsing" sound when receiving analog audio. This pulsing seems to be exactly 2 times per second. It doesn't really sound like a ticking or a signal in the background. It's most obvious with static in the background, when it almost sounds like audio compression is rapidly being turned up and down ("pumping"?). The actual VOICE transmission doesn't "pulse" as much as the background noise level rises and falls in a periodic rhythm.

When it's doing this, I can put the radio in monitor mode (receiving nothing but static) and clearly hear the pulsing.

Note that it doesn't always exhibit this problem.

I've ruled out local interference as the source, because (a) I hear this same phenomenon even many miles from home, and (b) my XTS-2500 doesn't exhibit this symptom at all when connected to the same external antenna.

Any clues would be greatly appreciated.

Peter
K1PGV
Last edited by PeterGV on Thu May 08, 2008 5:24 pm, edited 1 time in total.
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Josh
Posts: 1926
Joined: Mon Sep 03, 2001 4:00 pm
What radios do you own?: ASpectra+, XTS2.5K, Kenwood NX

Re: "Pulsing" Analog Audio?

Post by Josh »

It's probably the radio and due to old firmware. My XTS2500 with version R04.80.00 does it too. Time for an upgrade.
PeterGV
Posts: 76
Joined: Sun Nov 25, 2007 8:30 am

Re: "Pulsing" Analog Audio?

Post by PeterGV »

Good thought, but the firmware is R11.00.00, DSP R11.00.00

Thanks though,

Peter
MT2000 man
Posts: 1259
Joined: Tue Sep 04, 2001 4:00 pm
What radios do you own?: XTS5000R, Astro Saber III, I

Re: "Pulsing" Analog Audio?

Post by MT2000 man »

Hmmmm, may sound stupid and simple, but do you have your radio setup for priority scan ? That causes the pulse that you hear. I assume that you already checked that though . . .
PeterGV
Posts: 76
Joined: Sun Nov 25, 2007 8:30 am

Re: "Pulsing" Analog Audio?

Post by PeterGV »

Another good thought, but sadly no.

This radio doesn't have priority enabled, and there's no "little dot" after the "scanning Z" :-)

(added later via edit) Interesting tidbit: You suggestion made me check, and it appears that I can make the pulsing stop if I take the radio out of scan mode. It resumes if I start scanning again. Hmmmm....

Peter
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txshooter
Posts: 881
Joined: Mon Apr 15, 2002 7:15 am

Re: "Pulsing" Analog Audio?

Post by txshooter »

PeterGV wrote:Another good thought, but sadly no.

This radio doesn't have priority enabled, and there's no "little dot" after the "scanning Z" :-)

Thanks,

Peter
Is the radio scanning while this is occuring? Does the radio do this with scan off?
Just because you don't see the dot does not mean it is not priority scan. The radio can be set with the priority channel slaved to the channel selector or the priority channel can be slaved to one channel and not selectable by the end user. I don't remember if the dot shows up in these circumstances or not, but it really does sound like the priority scan pulse.
Scott B.
"Never argue with seven men when you are carrying a six shooter..."
PeterGV
Posts: 76
Joined: Sun Nov 25, 2007 8:30 am

Re: "Pulsing" Analog Audio?

Post by PeterGV »

Yeah... Thanks Txshooter... It DOESN'T do it with scanning disabled, which is something I just discovered tonight after reading MT2000Man's reply and playing with the radio some.

Me thinks I need to dig a big deeper and see if I've inadvertantly enabled a priority channel or something, now that I know what "priority scan" sounds like.

Many thanks to all of you... I'm off to investigate with CPS,

Peter
MT2000 man
Posts: 1259
Joined: Tue Sep 04, 2001 4:00 pm
What radios do you own?: XTS5000R, Astro Saber III, I

Re: "Pulsing" Analog Audio?

Post by MT2000 man »

Well, glad we could help :) I thought that sounded like a prioirty scan going on there.

I have all my radios set up where "B" it just scans, and "C" you can manually set up what channels to scan, and set up your priority as well (AKA Program Scan). At least now you found out what the issue was !
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