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.

Help With Injecting Audio into a GM300 for a DMR Repeater

Have a question or information regarding interfacing or interoperating Motorola digital radios with models from other manufacturers? Here's the place to do so.

Moderator: Queue Moderator

kb8qdx
New User
Posts: 3
Joined: Sat Jan 27, 2018 9:11 am

Help With Injecting Audio into a GM300 for a DMR Repeater

Postby kb8qdx » Sat Jan 27, 2018 12:24 pm

Greetings all,
I've been trying to find info on where to inject the TX audio on a GM300 to use for a DMR repeater to get the required 9600 baud for the transmitter. I have the HLE8300B RF board and all the info that shows where to inject the TX audio are for the HLD8029 board, Shown Here. The resistors and cap (R222, R223 & C228) that are referenced in the HLD8029 schematics are not the same as on the HLE8900B. Does anyone have any ideas on where I can obtain this information for the HLE8900B? I'm pulling my hair out over this and one would think it would be simple to figure out, but without a proper schematic, I'm shooting in the dark!! This is my first attempt at building a DMR repeater and I would like to get it up and running sometime in the near future!!

This is from batlabs referencing the HLD8029 RF board 9600 baud packet modification:

"The GM300 Series are 9600 baud packet capable. They do need a minor modification though. For RX, its no big deal, just take RX audio from PIN 11 of the Accessory Connector and swing JU551 to the (A) position (Flat RX Unmuted).

For TX audio, you will have to run a jumper to the junction of R223, C228, R222 on the RF board to inject the data (if applicable you may need to set the deviation pot in the radio to maximum). You might want to put a pot on your TX line somewhat like the setup Motorola uses (voltage divider) to adjust the deviation.

Again, this info assumes you have the HLD8029 board, which I do not!!

Thank you in advance for anyone that can help me with this..
Ernie
KB8QDX

ve3nsv
Posts: 282
Joined: Sat May 27, 2006 8:43 am

Re: Help With Injecting Audio into a GM300 for a DMR Repeater

Postby ve3nsv » Mon Jan 29, 2018 12:05 pm

Have you tried injecting the audio on pin 5?

kb8qdx
New User
Posts: 3
Joined: Sat Jan 27, 2018 9:11 am

Re: Help With Injecting Audio into a GM300 for a DMR Repeater

Postby kb8qdx » Mon Jan 29, 2018 12:18 pm

Yes I have.. That's what I've been reading, but also I've heard that the tx audio has to be injected in the VCO.. If you look at the link that I posted, it shows the place between R222 & R223 & C228, so I guess that's what I need to do, but I have a different board as said in my initial post.. Thank you for your quick response..

User avatar
jackhackett
Posts: 1432
Joined: Tue Jun 10, 2003 8:52 am

Re: Help With Injecting Audio into a GM300 for a DMR Repeater

Postby jackhackett » Mon Jan 29, 2018 4:19 pm

You can get the GM300 manual from the repeater builder site. It comes in 5 sections, you want to look at part C. Find the HLE8300 board layout, and on the component side look at the top right section, you should find those resistors and cap there. They have the A version board, hopefully the B version is similar.


Return to “Motorola Digital Radio Compatability”

Who is online

Users browsing this forum: No registered users and 2 guests