Icom F4061 breaking squelch constantly

[charlied]

I have programmed in a local frequency for listen only. It's obviously a UHF frequency. It's a conventional setup with the xmit and rec freq being the same with no code. As basic as you can get.
The problem is at approximately every 8 to 10 seconds I get a signal that breaks squelch. Not long enough for data or voice. Similar to just bumping the xmit button.
I have set the squelch to 0 and everywhere in between to 255 and still have the same issue.
I get all radio traffic just fine.
I have the digital board installed but have no digital frequencies set up.

Any ideas what might be the issue?

 

[12dbsinad]

I have programmed in a local frequency for listen only. It's obviously a UHF frequency. It's a conventional setup with the xmit and rec freq being the same with no code. As basic as you can get.
The problem is at approximately every 8 to 10 seconds I get a signal that breaks squelch. Not long enough for data or voice. Similar to just bumping the xmit button.
I have set the squelch to 0 and everywhere in between to 255 and still have the same issue.
I get all radio traffic just fine.
I have the digital board installed but have no digital frequencies set up.

Any ideas what might be the issue?

Are you sure what you have programmed in not a LTR home channel? It would do exacly as you described. It transmits a quick data burst every few seconds.

 

[charlied]

Under the software heading "Model" LMR (Digital) is checked.
My selections are;
LMR 2 zone
LMR LTR
LMR Digital
PMR 5-tone DTMF
BIIS PMR

 

[12dbsinad]

It wouldn't be a setting in the radio, the home channel is part of a LTR trunked system. Try programming that freq into another radio or scanner (if you have one) and see if it does the same thing.

 

[charlied]

Have already done so.
Problem does not show itself.

 

[charlied]

I may have to correct myself. I think the squelch break is picked up by another radio. Have removed the antenna and the squelch break goes away along with all radio traffic.
This is not a trunked system or is it and the info is not in the db?
It's as basic as you can get UHF conventional system. 454.625
As I stated before the send and receive frequencies are the same with no transmit CTCSS code.

 

[mmckenna]

Does it just do it on 454.625, or does it do it on other UHF frequencies?

 

[charlied]

Just this one.
I think I have found the solve to the issue.
This is what happends when you don't read everything.
At the bottom of the page is listed an 800 trunked system for Houston County PS.
Curious though as to why you can receive and transmit on the UHF.
I'm not really sure the trunked system is used

 

[12dbsinad]

I may have to correct myself. I think the squelch break is picked up by another radio. Have removed the antenna and the squelch break goes away along with all radio traffic.
This is not a trunked system or is it and the info is not in the db?
It's as basic as you can get UHF conventional system. 454.625
As I stated before the send and receive frequencies are the same with no transmit CTCSS code.

It is possible that the info is not updated in the DB. It appears that all of that info is rather old. If it does it with another radio and it does it all the time at any location, it is safe to say its not a problem with the Icom but a function of the system you are monitoring.

Like I said, a LTR system does just that if you are monitoring the home channel in conventional mode. You will however miss replies and other traffic when it trunks to another channel. I did a quick search on FCC on that specific freq and came back with a part 22 license for a communications company out of Webb.

 

[ElroyJetson]

If your radio is breaking squelch when set to carrier squelch, the most probable answer is that there is a real signal present. I've programmed, used, and worked on many of that model radio and if they have any problems with squelch, it's not that they break squelch for no reason, but are slightly more likely to NOT break squelch when they SHOULD.

 

[fontanei]

Don't rule out the possibility of your radio picking up a spurious emission from some other transmitter (harmonics, mixer products, etc)

Does it happen wherever you are physically or is it just in a specific location?

Do you have access to a spectrum analyzer?

From what you've said, it appears to be externally generated....Not generated from your own radio.