Curious sounds I constantly get.

[flyingwolf]

Ok while scanning on my 92b i have on occasion come across this. Only on this frequency 856.2625 which is Union Township dispatch (ohio Clermont county) I get this very annpoying screching and bleeping sound.

I have attached the audio files so you can hear them for your selves.

The first file Normal Audio.mp3 is how the normal audio sounds. Be careful becuase I had the squelch completely open and about 20 seconds into the file the squelch opens pretty loud. Just a warning there. But you will also hear that it is quite noisy. It al depends on the day. Some days its as clear as a bell.

The second file is the noise in question. unknown sound.mp3. That is the sound that breaks squelch often when there is no other transmission to speak of. So what is it?

The third file is the whole soundfile in its complete form. There is alot of noise and full open squelch on it. If you want to listen all the way through that is the one to go with. Whole File.mp3.

 

[Joseph11]

Heh, as soon as I started playing that, I heard fire pager sounds and thought it was on the clip, but it was on my scanner. Anyway, that sounds really familiar, I know I have heard it some where else.

 

[flyingwolf]

Ok it looks like nothing I do will let the damn 3rd file upload. So if you want it ill email it. Only diff is I cut out some silence. And some of the hard squelch noise.

So if you want it ill email it to you.

 

[flyingwolf]

Its a strange sound. And it is a constant repeating sound. It goes for 5 to 6 seconds off for 2 then repeats. And only seems to do it once in a while. Not all the time. Not every day.

 

[Voyager]

Ok while scanning on my 92b i have on occasion come across this. Only on this frequency 856.2625 which is Union Township dispatch (ohio Clermont county) I get this very annpoying screching and bleeping sound.

I would say that's an MDT transmission.

Joe M.

 

[Joseph11]

Ok while scanning on my 92b i have on occasion come across this. Only on this frequency 856.2625 which is Union Township dispatch (ohio Clermont county) I get this very annpoying screching and bleeping sound.

I would say that's an MDT transmission.

Joe M.

It does sound like that, I can't figure out which protocol, though.

 

[flyingwolf]

Thing is its on the same frequency and CTCSS as the voice traffic?

Is that normal?

The LEO would be hearing the same thing.

 

[Chris-M]

That is an unusual sounding databurst. Are you sure it's being transmitted on the frequency/frequencies you're monitoring, and that it isn't a local signal that is so strong it's overmodulating and bleeding thru the front-end of your receiver? In one of the clips it sounded like it was mixing somewhat with the voice modulation. Do you live near a military base or something? Maybe it's a different frequency that's a harmonic of the one you're hearing it thru the scanner?

I don't think it's MDT data. That sounds nothing like the local MDT modulation here.

 

[Videokid]

The second sample sounds like an MDT to me. As for the first sample it sounds like near field interference. One of my scanners was sitting next to a PC once and every once in a while RF interference from the spinning hard drive would overload the front end of the receiver.

 

[flyingwolf]

First and second sample if played one after the other is how the file originally sounded.

I do have the scanner close to a pc but I only get the interference on this particular frequency.

I actually live not to far from the transmitter but closer to a small airfield.

It only happens on this freq though. I dont pick up anything (and dont have any programmed either) in this freq range. This is the only 800 mghz freq I ever hear.

Maybe its a bleed through as you say. Ill have to try a combination of moving the scanner and recording and filtering to see what I can come up with.

Thanks for the ideas.

Keep em comming.

 

[Voyager]

Thing is its on the same frequency and CTCSS as the voice traffic?

Is that normal?

The LEO would be hearing the same thing.

Exactly. Are you SURE it's transmitting the SAME CTCSS? The ones I'm familiaer with DO operate co-channel, but without CTCSS to the users don't hear them.

Joe M.

 

[nd5y]

That is interference from a Flex paging transmitter, probably in the
929 - 932 MHz range. I get that all the time here. Sometimes it sounds like
flex mixed with a motorola control channel or other signals.

Tom

 

[cassidy1190]

I get that too here on the Jersey Shore. I listened to your clip and I think the decription of my sound is a little different then your problem though. Its more like what nd5y says. Its like if you took every radio transmision in the world and crammed it all togethor with a control channel and some other funky noises. Its quite an awful sound. It goes for about 6-8 seconds and then stops. I only started to get the interference when I got a discone antenna. Is there anything you can do about this?(besides getting rid of the discone lol...)

 

[Joseph11]

That is interference from a Flex paging transmitter, probably in the
929 - 932 MHz range. I get that all the time here. Sometimes it sounds like
flex mixed with a motorola control channel or other signals.

Tom

You are right, http://www.kb9ukd.com/digital/flex.wav is a sample of the FLEX paging protocol.

 

[flyingwolf]

Anyway to get rid of that interference.

And yes its the same CTCSS the whole time. The bank is closed and only has the one channel in it.

 

[Voyager]

Anyway to get rid of that interference.

And yes its the same CTCSS the whole time. The bank is closed and only has the one channel in it.

Just because it's a FLEX format doesn't mean it's coming from a 900 MHz paging transmitter.

If it's got the CTCSS on it, too, the users are most likley hearing it as well. It may be an in-house paging setup, but I don't know why they would have the CTCSS active with it.

Joe M.