Annoying Sound

[thomast77]

Ok so I have been getting this really annoying sound (interference) on my scanner. It is very frustrating because it is on one of the main Sheriff department channels. It gets so strong that turning the squelch all the way up does not get rid of it. I have to disconnect the outdoor antenna attach the rubber duck and turn the squelch up to get rid of it. The sound comes and goes. I could go a week without hearing it. But then when it comes back it may be a problem for a couple of days. It is perplexing because it does not sound like paging to me. I have attached a short clip of the sound. I am trying to figure out what the sound is and how to get rid of it. This is just a short clip but if you put it on a loop that is exactly what it sounds like here. It is continuous without pause. I would greatly appreciate your input if you know what it is. I really have no idea what it is. But maybe someone else here has heard it before.
Thanks for your time
Tom

 

[thomast77]

I am attaching a second clip I just made which is much clearer and stronger sounding.

 

[kma371]

Ok so I have been getting this really annoying sound (interference) on my scanner. It is very frustrating because it is on one of the main Sheriff department channels. It gets so strong that turning the squelch all the way up does not get rid of it. I have to disconnect the outdoor antenna attach the rubber duck and turn the squelch up to get rid of it. The sound comes and goes. I could go a week without hearing it. But then when it comes back it may be a problem for a couple of days. It is perplexing because it does not sound like paging to me. I have attached a short clip of the sound. I am trying to figure out what the sound is and how to get rid of it. This is just a short clip but if you put it on a loop that is exactly what it sounds like here. It is continuous without pause. I would greatly appreciate your input if you know what it is. I really have no idea what it is. But maybe someone else here has heard it before.
Thanks for your time
Tom

Can you add a PL or DCS tone to the agency your listening to? that way you only hear them instead of noise.

 

[thomast77]

kma371: Unfortunately my scanner does not have that feature. But my next one will (when I can afford it)

 

[SEQLD_SCAN]

Annoying sound

That sounds like a digital cordless phone getting into the scanner. (note : not a cell phone).
If you have a cordless phone in the house, try switching the base unit off when you hear the sound.
Also, wireless devices such as cordless mice and keyboards can also generate digital rubbish over a short distance. ie: is the scanner near a PC?

 

[jim202]

You haven't provided any info on the frequency that your trying to hear. Being in the radio field
for well over 45 years now, I think I would make a stab and say that your trying to listen to
a low band channel. It almost sound like the data used on a cable TV system. This is
normally down at the low end of all their channels.

If it is cable TV leakage, you can try looking around the sound carrier frequencies in the 155 MHz
range. If you hear the audio from a TV channel say on the 155.76 area, then it's from the cable
system and they are having too much leakage. Trying to get it fixed may present a major
effort on your part to contact someone that gives a hoot.

Jim

Ok so I have been getting this really annoying sound (interference) on my scanner. It is very frustrating because it is on one of the main Sheriff department channels. It gets so strong that turning the squelch all the way up does not get rid of it. I have to disconnect the outdoor antenna attach the rubber duck and turn the squelch up to get rid of it. The sound comes and goes. I could go a week without hearing it. But then when it comes back it may be a problem for a couple of days. It is perplexing because it does not sound like paging to me. I have attached a short clip of the sound. I am trying to figure out what the sound is and how to get rid of it. This is just a short clip but if you put it on a loop that is exactly what it sounds like here. It is continuous without pause. I would greatly appreciate your input if you know what it is. I really have no idea what it is. But maybe someone else here has heard it before.
Thanks for your time
Tom

 

[thomast77]

Sorry I did not think about adding the frequency. It is 460.400.

 

[Bill_White]

Sounds like MDT to me....

 

[thomast77]

What is MDT?

 

[b7spectra]

That sound reminds me of the cold war "woodpecker" used in jamming. It could be a tone sent out by the user to disrupt scanner listeners. What you could do is take your scanner mobile and drive to different areas of town and see if it is still there. If so, I would go with the agency sending it out. Also, check the FCC database to see if there is someone else nearby on the frequency.

MDT - Mobile Data Terminal - i.e. the in car computers.

 

[thomast77]

I have noticed there seems to be some long distance vhf/uhf propagation in my area the past couple of days. I am hearing fire and police dispatch from hundreds of miles away sometimes on the same frequency as the fire or police dispatch in my local area. I had to disconnect the outdoor antenna because I am having a hard time hearing what is going on locally. For instance, I am monitoring Santa Rosa County, FL Central Fire Dispatch on 154.160 and I keep hearing Live Oak,FL Fire Dispatch. Live Oak is about 300 miles away!!! Maybe this sound has been getting stronger the past couple of days because of propagation. And it does seem to come and go. I found this site helpful with Propagation Maps. VHF Propagation Map
I am right in the middle of the big red blob in the Florida panhandle. So perhaps some police agency within a couple of hundred miles is operating MDT on 460.400 and I hear it when the propagation picks up.

 

[SCPD]

I'm not gonna say I know what it is, but I 'm pretty sure that from the way you explain that it goes away when you disconnect the external, that data signal is something in the neighborhood. Some Part 15 device a neighbor is using for something. It may your next door neighbor's fridge telling the water valve to open to the ice machine on the front door. Next time this does this, jump in the car and cruise the 'hood.

 

[thomast77]

Yes it is sitting right next to my Laptop which has a cordless mouse and wireless connection to the router. But it does not happen all the time. Maybe I will try moving the scanner away from the computer next time it happens. Thanks for your input.

That sounds like a digital cordless phone getting into the scanner. (note : not a cell phone).
If you have a cordless phone in the house, try switching the base unit off when you hear the sound.
Also, wireless devices such as cordless mice and keyboards can also generate digital rubbish over a short distance. ie: is the scanner near a PC?

 

[thomast77]

Or maybe I can go for a walk. I will give it a try when it happens again.

I'm not gonna say I know what it is, but I 'm pretty sure that from the way you explain that it goes away when you disconnect the external, that data signal is something in the neighborhood. Some Part 15 device a neighbor is using for something. It may your next door neighbor's fridge telling the water valve to open to the ice machine on the front door. Next time this does this, jump in the car and cruise the 'hood.

 

[DickH]

Or maybe I can go for a walk. I will give it a try when it happens again.

Maybe you hear it in this list. of sounds.
Digital Modes Samples

 

[thomast77]

Thank You for the link. This could come in real handy.

Maybe you hear it in this list. of sounds.
Digital*Modes*Samples

 

[datainmotion]

That sounds like a digital cordless phone getting into the scanner. (note : not a cell phone).
If you have a cordless phone in the house, try switching the base unit off when you hear the sound.
Also, wireless devices such as cordless mice and keyboards can also generate digital rubbish over a short distance. ie: is the scanner near a PC?

+1 on the cordless phone. This is what the ringer sounds like on some models when hearing them on a scanner...or so I have been told :roll::lol:

 

[thomast77]

If it was a cordless phone should it be continuous interference? The problem I am having is that it only happens for a day or two then It may not occur for another week or two. Right now I have no interference even if I turn the squelch all the way down. Nothing but static.

+1 on the cordless phone. This is what the ringer sounds like on some models when hearing them on a scanner...or so I have been told :roll::lol:

 

[SEQLD_SCAN]

Annoying sound

Thomas, did you find the cause of the noise yet?

 

[thomast77]

It may be MDT as someone pointed out above. Whatever it is I only here it when there is high VHF propagation. So it is not local. I believe it is MDT or some digital communications that is normally outside of my receive range. VHF propagation has been strong the past month or so in my area. I did listen to alot of the sounds on the Digital*Modes*Samples page. MDT was the closest I could find. Here is the link I use for VHF propagation VHF Propagation Map