Tones Cutting Out During Recording.

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crossfire291

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Hey, I've been recording fire dispatches here and there, and have noticed something odd, that I have no solution for as of yet.

Basically, I'll be recording, and a dispatch gets toned out, but you only hear the first part of the tone in the recorded audio. The other part of the tone seems to be silent until the dispatcher ques the mic. I would love to get to the bottom of this, and possibly find a way to correct this, so any input is appreciated.

Here is a recording that I uploaded to Youtube. You will hear a long pause in audio between the tone, and dispatcher. That silence is supposed to be all tone.

http://www.youtube.com/watch?v=UaEracBX6Bs
 

motomeso

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Are you recording from the trunking system or from the VHF Paging frequency.

Hey, I've been recording fire dispatches here and there, and have noticed something odd, that I have no solution for as of yet.

Basically, I'll be recording, and a dispatch gets toned out, but you only hear the first part of the tone in the recorded audio. The other part of the tone seems to be silent until the dispatcher ques the mic. I would love to get to the bottom of this, and possibly find a way to correct this, so any input is appreciated.

Here is a recording that I uploaded to Youtube. You will hear a long pause in audio between the tone, and dispatcher. That silence is supposed to be all tone.

C-K Fire - Stations 18 & 19 Test Pages - YouTube
 

crossfire291

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Are you recording from the trunking system or from the VHF Paging frequency.

I'm pretty sure it's on the VHF, but it could be UHF. Where I am, the Fire Dept. uses 2 different ways of paging. The first is to the bases, on 154.680, which is UHF. The second is city to city water tower repeaters, on 414.1375, which is VHF.
 

n5ims

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Do you have the PL programmed in? Quite often the tones are sent without the PL so if they're programmed in you won't hear the tones.
 

crossfire291

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Do you have the PL programmed in? Quite often the tones are sent without the PL so if they're programmed in you won't hear the tones.

I can hear the tones. The issue is only with the recorded audio. everything is fine on my scanner, but when I playback the recording That's when I get issues. When I playback, I get the first part of a tone, but not all of it. I use an analog scanner by the way, so I only have the freqs programmed.
 

krokus

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What are you using to record? Is there a chance that a "data mode" is being detected, and the audio not saved?

Are the 2nd tones in the audio passband of the recording system?
 

talkpair

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Another strange thing about the recording is that there are PL tones that seem to come and go while the dispatcher is talking.

In the first test, it sounds like a 110.9 PL comes on toward the end of that voice transmission.
In the second test, it sounds like a 136.5 PL comes on, goes off, then comes back on.
In the 3rd and 4th test, a 156.7 PL is audible at the beginning of the voice transmission, then switches off

Are the 2nd tones in the audio passband of the recording system?

This would be a good item to check as well......Look for a lowpass setting and make it higher if the 2nd tone is a high frequency
 

crossfire291

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What are you using to record? Is there a chance that a "data mode" is being detected, and the audio not saved?

Are the 2nd tones in the audio passband of the recording system?

I'm using Audacity to record, and I can't determine if there is a data mode being detected.

About these other tones, I have know idea. I only know what I have already said earlier. If I am able to find anything else out, I'll be sure to let everyone know.

Thanks for the help so far guys.
 
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