Batboard

Hi I am Ziga from Croatia.
First sorry for my language.

I have Motorola GP300 UHF.
Sometimes when I push PTT my outgoing voice is very low, then I must release and push PTT few times and than my voice modulation is OK.
I change a internal mic but is the same.

When is cold weather it work ok few minutes, and then start a problem.

Please help me!

Have you tried using an external speaker mic? You
might have a bad connection on the jack where the
external mic plugs in.

Jim

ziga wrote:Hi I am Ziga from Croatia.
First sorry for my language.

I have Motorola GP300 UHF.
Sometimes when I push PTT my outgoing voice is very low, then I must release and push PTT few times and than my voice modulation is OK.
I change a internal mic but is the same.

When is cold weather it work ok few minutes, and then start a problem.

Please help me!

Hi Jim!

No I am not try because I havent it, but I try put a contact spray in that socket and it is the same.

My friend have external mic/speaker and I will try with it!!!

Sounds like a problem with the accessory jack and if my memory is correct they are a cow to change.

I bet he has a weak mic. element which will cause the TX audio to be soft.

But yes, the audio connector on the top of the radio is a bear to swap out if you do not have access to a vacuum desoldering station.

The connector assy. is a one-piece 'affair' and those contacts get a lot of debris inside and cause a multitude of audio related problems with the biggest being poor contact from over-use and weak 'fingers' in the housing, not to mention corrosion from moisture ingress.

He could also gently crimp the pins the plug attaches to, just to ensure a better electrical connection, but he must be very cautious on how much pressure is used, as too much will ruin those tiny sockets....then he'll be stuck with direct soldering to avoid future troubles if all else fails.

Those mic. elements are electret condenser types and require +5V for operation, and the dielectric does become weak after many years of service.

My first choice would be to simply replace the mic and run the service menu to check actual mic gain and levels to be certain.

Yesterday I was changed mic again and today I will try to find out if this works.
In my service menu mic gain is"0" but the problem is that mic sometimes work and sometimes work very quiet.

Please can You tell me on witch level must be my mic level????
In my second GP 300 mic level is 0 and it works very well.

Thanks very much for your reply.

Yopu can probably set the mic. gain to +3 without any troubles arising, but the best method is to use a service monitor to watch the transmitted audio as you do not want to cause splatter or IMD products to be generated with too much gain.

I'd be willing to bet you can safely crank it up to +3 without any troubles whatsoever though.

As I stated earlier, it does sound like you have a mic. element starting to go bad, which causes the mic. gain to drop or rise depending on use.
It's a touchy situation as it can work well for long periods, then drop at a moment's notice, to give the appearance of some other problem.

Thanks AEC for you time for helping me!

I put a new one mic element and for now it work well, i hope that will be ok now.

Thanks again!

Bye!

Ziga:

Always a pleasure to help!

I'm glad the radio's up and running again, and this time, with speech!

73!