GM300 rx pl problem

[g4tuz]

Hi I have a VHF GM300 146 - 174 MHz (8 channel unit converted to 16 channel). Some ham repeater frequencies are setup for rx tpl, however the receiver opens with plain carrier, no pl required. Is this a programming problem RSS 1.00.00 or are there any common hardware problems causing this. The pl tones generated on tx work fine.

Regards

Paul

[moztas]

Check positions of JU551 (default is B), JU601 (default is A) and JU809 (default is A) on the GM300's controller board. These jumpers related with receiving. If radio used as receiver of a GR500 repeater with R.I.C.K unit, jumper positions could be changed or removed.

You may also try to find service manual of GM300 on internet. It is easly to find it. Check page number 22, you will find more detailed informations about jumpers.

Regards
moztas

[Will]

Two things come to mind.

1) Is the Mic "hung up" so the metal button is grounded?

Radio will not go into PL receive unless the 'hang up stud' is grounded, off monitor.

2) Bad capacitor in the receiver, 33uF 25 volt.

[g4tuz]

Thanks for such a quick reply, yes the problem was lack of ground to mic stud, am using this radio at home so not using the mic clip. Is there a way to permanently enable the pl on rx if programmed, such as a jumper inside the radio?

Very many thanks

Paul

[Will]

If you have the black GM300 mic, add a jumper inside the mic.

[moztas]

Thanks for such a quick reply, yes the problem was lack of ground to mic stud, am using this radio at home so not using the mic clip. Is there a way to permanently enable the pl on rx if programmed, such as a jumper inside the radio?

Very many thanks

Paul

Find J8 on the controller board which goes "VOLUME/MIC BOARD and INT SPEAKER" board. Pin 15 is HOOK (hook pin goes directly to mic metal button) so if you solder this pin to ground your problem will solved permanently. I did it many times before. By the way, J8 pin #15 is next to J9.

moztas