Batboard

I seem to remember the GP300 having a connector at the bottom for optional add-on boards, like aftermarket signalling and such.

Does anyone have the pinout for that?

And does anything need to be enabled in the radio?

Thanks.

If you're looking at making it a repeater wouldn't you be better just to hook it to a small controller of some sort externally?

This should help:

http://www.w8ak.com/portrptr/index.html

W8AK has made a repeater out of GP300's and describes how he did it.

Are you talking about a connector inside the radio, Jonathan?
The GP350 (which I thought had the same guts as the 300) had what they called the AVS Advantage port or something inside.
I have an inverter board for the 350 but I never did get it working last I tried, um, 10.5 years ago:
http://batboard.batlabs.com/viewtopic.php?f=1&t=29028

tsunami_australia wrote:If you're looking at making it a repeater wouldn't you be better just to hook it to a small controller of some sort externally?

I'm looking to connect it to a DMK URIx sound fob dealie to use app_rpt.

wd9cms wrote:This should help:

http://www.w8ak.com/portrptr/index.html

W8AK has made a repeater out of GP300's and describes how he did it.

Doesn't really help because there's no schematics of where they tapped the discriminator or where they found a place to inject flat tx audio.

Motorola built a repeater that uses GP300 radios in it. No real mods to the radios. They do not use a 'disc tap' or flat audio'.

Systel SE Repeater. http://batboard.batlabs.com/viewtopic.php?f=10&t=66093

I have a few in service and the SM.