Audio cutting out

A place to talk about everything Radio and Scanning

Audio cutting out

Postby hhpilot » Tue Dec 05, 2017 9:11 am

Hi, wonder if anyone can help me with this. I have a Bearcat 125xlt which I have on in the background tuned to Farnborough Radar, as I am studying for private pilots license and want to get used to radio chatter.
The signal where I am is pretty strong, five bars from the controller station.

My proble is the audio cuts up, almost as if it were a weak signal and it is dropping below squelch threshold. If I turn squelch off, then it is absolutely fine but obviously pretty irritating between transmission, which is most of the time. I don’t have this problem on other frequencies with strong signal, for example the London Volmet is strong and doesn’t drop out at all. So it seems specific to this frequency (123.225).

I winder if it is actually signal overload. However if I attenuate the signal then I would not be able to hear the other side of the conversation from aircraft. And their signals are chopping up too which makes me think it is not to do with signal overload.

Any tips very welcome!
hhpilot
 
Posts: 5
Joined: Mon Dec 04, 2017 3:49 pm

Re: Audio cutting out

Postby moj » Tue Dec 05, 2017 10:11 am

As always first thing to check is your closecall priority is turned off , I used to leave mine on closecall dnd ;)
moj
 
Posts: 477
Joined: Wed Nov 21, 2012 9:10 pm
Location: uk , northwest

Re: Audio cutting out

Postby hhpilot » Tue Dec 05, 2017 4:22 pm

Hi thanks, good suggestion. Unfortunately I checked and cc priority and close call are both “off”already, so it’s not that.
Any other suggestions welcome!
hhpilot
 
Posts: 5
Joined: Mon Dec 04, 2017 3:49 pm

Re: Audio cutting out

Postby maylandmanta » Tue Dec 05, 2017 5:45 pm

Don't have a 125 myself but does it have priority channel scan by any chance ?, which has inadvertently been turned on

Steve
maylandmanta
 
Posts: 265
Joined: Sat Nov 24, 2012 5:39 pm
Location: N.E. Essex

Re: Audio cutting out

Postby hhpilot » Wed Dec 06, 2017 7:54 pm

Thanks for that suggestion - it does has a priority channel feature, but it's switched off. In any case, I'm only getting the problem on this one frequency (that I know of). The only thing I can think of that's "special" about this frequency is that it has a very strong signal (at least from one side of the conversation). And it's odd that it is absolutely fine with squelch off, but chops up with squelch on. Normally that would be a feature of a marginal signal.
hhpilot
 
Posts: 5
Joined: Mon Dec 04, 2017 3:49 pm

Re: Audio cutting out

Postby m0lsx » Thu Dec 07, 2017 12:12 am

Just a thought, but you do not have a strong local signal from an FM broadcaster on 107MHz do you? The internal frequency of the 125 is 16 MHz, that could mean that a strong signal on 107 MHz plus that 16MHz would mix to make 123MHz & FM broadcast signals are wide.
The 123.225 plus 16 is 139.225, so probably nothing there.
What antenna are you using? Any pre amp?
It could be overload. If the signal is big on the standard duck, then try the radio on it's side to reduce the signal level, see if that helps. If it is still a strong signal, then turn the base of the radio towards the transmitter to further null the signal & try that.
The fact it is happening on a
Buy a database from Kimmy JS19 via http://ukscanningdirectory.co.uk/
Or do Google search of this forum via https://www.google.com/cse/home?cx=partner-pub-6291336405621919:2662881632
73 De Alan (M0LSX.)
http://www.qrz.com/db/M0LSX"
User avatar
m0lsx
 
Posts: 5420
Joined: Wed Nov 21, 2012 9:14 pm
Location: Norwich. TG21.

Re: Audio cutting out

Postby hhpilot » Fri Dec 08, 2017 12:58 am

Not sure about the 107mhz signal, will have to check that out.
I’m using a simple half wave dipole antenna. No pre-amp.
The problem with reducing the antenna effectiveness to weaken the signal is then I weaken the remote station (i.e. aircraft) side of the conversation too, which sort of defeats the purpose.
Weirdly, it was ok for a while this morning, then rubbish again in the p.m.
hhpilot
 
Posts: 5
Joined: Mon Dec 04, 2017 3:49 pm

Re: Audio cutting out

Postby m0lsx » Fri Dec 08, 2017 9:00 am

hhpilot wrote:The problem with reducing the antenna effectiveness to weaken the signal is then I weaken the remote station (i.e. aircraft) side of the conversation too, which sort of defeats the purpose.


The idea of reducing the signal strength was to see if your radios front end is overloading. And what you describe could be a symptom of overloading. Yes you will loose one side of the conversation, but you will find out if it's an overload issue & then know if it's overload or not.
A handheld radio is designed to work on a handheld radios antenna. It has no attenuator & overloads very easily, as it's designed to work on an inefficient antenna.
Buy a database from Kimmy JS19 via http://ukscanningdirectory.co.uk/
Or do Google search of this forum via https://www.google.com/cse/home?cx=partner-pub-6291336405621919:2662881632
73 De Alan (M0LSX.)
http://www.qrz.com/db/M0LSX"
User avatar
m0lsx
 
Posts: 5420
Joined: Wed Nov 21, 2012 9:14 pm
Location: Norwich. TG21.

Re: Audio cutting out

Postby hhpilot » Sat Dec 09, 2017 10:55 am

Fair point, I will try that.
hhpilot
 
Posts: 5
Joined: Mon Dec 04, 2017 3:49 pm


Return to Radio and Scanning Chat

Who is online

Users browsing this forum: No registered users and 2 guests