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