Users may not create topics, posts, or private messages containing or relating to the following material (especially pertaining to Motorola copyrighted software, unless you want Motorola to come along and shut this site down):

  • Listing for sale or trade of, or links to sites offering for sale or trade of, or giving away, Radio
    Service Software (RSS) or Customer Programming Software (CPS)
  • Profanity, pornography, defamation, or slanderous remarks directed towards any individual or entity
  • Commercial advertising (except in the Batboard Vendors forum, as approved by the Admin/Mod Staff)
  • Any other items which may be deemed as offensive

If any topics, posts, or private messages containing or relating to the aforementioned material are brought to the attention of the Admin/Mod Staff, they will be deleted.

Additional FAQ items appear here in Forum Rules. Please review them for posting guidelines and further clarification.

GM300 UHF PL/CTCSS Question

The General forum is where users can discuss any topic regarding Motorola communications equipment - hardware, software, etc. There are also several focused forums on this board, so please take the time to ensure that your questions doesn't fall into one of those categories before posting here!

Moderator: Queue Moderator

New User
Posts: 1
Joined: Tue Sep 11, 2018 12:12 pm

GM300 UHF PL/CTCSS Question

Postby twillweaver » Wed Sep 12, 2018 4:55 pm

I have a GM300 8-ch UHF (438-470MHz) that I've reprogrammed for a few of the local repeaters near me. The main one I use is set up on channel 1 - I can receive and transmit with this one fine.

But with at least one of the rest of the programmed channels, I've noticed that the squelch doesn't open when the repeater transmits. Channel 3 for an example...

I have confirmed the Rx/Tx frequencies and the squelch tones with the listed repeater info, and I have the same programmed into both a Yeasu and Baofeng and they receive and play audio while the GM300 sits silently while the mic is hanging. Naturally, if I pick up the mic or press the monitor button, it plays received audio just fine.
I'm not sure what to do about this. Has anyone encountered this in the conversion of commercial-to-ham radio? I won't rule out that I'm just an idiot, but I'm really thinking that it's not me, this time.

User avatar
Posts: 279
Joined: Tue Oct 02, 2001 4:00 pm
What radios do you own?: Too many for the time I have.

Re: GM300 UHF PL/CTCSS Question

Postby kb4mdz » Thu Sep 13, 2018 4:03 am

Poor PL decode? Poor PL Encode on the repeater output? (level too low, or distorted)?

User avatar
Posts: 1439
Joined: Tue Jun 10, 2003 8:52 am

Re: GM300 UHF PL/CTCSS Question

Postby jackhackett » Thu Sep 13, 2018 6:00 am

Is it a 12.5KHz radio? What is the model number?

If you have a 25KHz radio the PL level from a 12.5KHz repeater may not be high enough to open the squelch.

User avatar
Posts: 1439
Joined: Tue Jun 10, 2003 8:52 am

Re: GM300 UHF PL/CTCSS Question

Postby jackhackett » Thu Sep 13, 2018 7:20 am

Also, do you know what bandwidth the repeaters are using?

User avatar
Andy Corbin
Posts: 133
Joined: Tue Apr 19, 2005 3:46 pm

Re: GM300 UHF PL/CTCSS Question

Postby Andy Corbin » Thu Sep 13, 2018 7:21 am

Does the transmit tone on the GM300 open the repeater? Also, if you have an HT or another radio or even better yet, a service monitor, try setting the repeater output frequency and tone on one of them and see if it opens the receiver.

Posts: 38
Joined: Tue Dec 16, 2003 8:27 am

Re: GM300 UHF PL/CTCSS Question

Postby jpu535 » Fri Sep 14, 2018 9:37 am

I assume you are talking about ham radio use and not commercial part 90 2-way because then we would need more info on whether that radio has been modified for narrow band or not.

I believe this is going to be a programming issue. It's been a long time since I've been into a GM300 but check to see if you have a mute/unmute rule in your personality setting to make sure they are the same for the channel that does work. The fact that you are taking the mike off hook and you can hear in monitor mode is a classic sign that I have experienced in the past with bad programming with an unmute rule somewhere in the code plug. I believe you want standard/standard which means to unmute on proper PL and mute on loss of PL. I don't recall if the 8 channel radio is scan capable too but if you are trying to scan you could have an issue there if you are in scan mode. Like I said it's been a while for me with these GM300 so my information could be off a little too.

Return to “General Motorola Solutions & Legacy Radio Discussion”

Who is online

Users browsing this forum: 545 and 5 guests