MAXTRAC GM 300

[elmanoduarte]

Hi all.
I m tryng to mount a cross band repeater with a GM300 VHF and a MAXTRAC 300 UHF radios.
The 16 pin out on the back Look same on both of radios, but mabe the cable to make the connection in the 16 Pins on the radios dont work like in 2 GM300.
Anyone know the 16 pin diagram from the MAXTRAC 300 ?
I think it ould need change the connections in the MAXTRAC pins.

 

[a417]

You been here, yet?

 

[elmanoduarte]

Thank you very much for answer.
Yes, i have saw that but could not find the 16 pins out connections.

It should be identical to GM300, but its not!
Cant make it work, dont want to make wrong connection pin and burn the radio.

Many years ago i have done by a wrong pin connection in a GM300 and it burned the Pico Fuse inside. For my luck it was just that.

 

[a417]

Whoops, linked the wrong page. I think I sent you the GM300 and I meant to send you the page that covers the Maxtrac.
Each page has links to the relevant images of the accessory connectors. There are slight differences between the two.

 

[elmanoduarte]

Good.

Many thanks.
Now I think I will be able to change the cable from the MAXTRAC side.
I will identify the IN, OUT, PTT , GND it should work.

Thank you very much.

73

 

[a417]

You need to bookmark this page, if you're going to deal with antiques like that. Lots of good information.

 

[elmanoduarte]

Ok. Many thanks.

 

[xmo]

All sorts of information, interfacing, manuals, etc:

Motorola MaxTrac / Radius / GM300 Index Page

 

[elmanoduarte]

Good morning.
Many thanks.

The LINK from a417 have the scquematic from the 16 Pin out.

I think now I will be able to change the repeater cable from the MAXTRAC UHF side.
going to test it now, I will let you know how it was,

best regards, for all

 

[elmanoduarte]

have blow the Pico Fuse!
insert the fitting 16 Pin cable backwards

Going to replace it, I have alot PICo FUSES, the little GREEN.

Then I will try agian...
going to start replace now.

 

[P25Radio]

Make sure in your CPS you have the correct settings for the pins!!

 

[a417]

Make sure in your RSS you have the correct settings for the pins!!

FTFY.

 

[elmanoduarte]

Good morning.

For CPS it works normaly like GM300, just with another CPS.
I already switched the PICO FUSE.
Here´s the picture just for anyone need it.
Its very identical to GM300 board. Identical, not same! But the Pico Fuse its the same.
The Green one, its a small fuse with 2A.
Normaly blow when any short circuit in the 16 Pins out.
SOme times it Blows the Crystal to, not always like this time.

 

[elmanoduarte]

Another think I did realised, its..
I was using a cable for 4 Way switching.
Have used this cables many, the 2 radios will make TX and RX with 4 distinct frequencies.
Its good for LINK.

So with that cable it does not work with no changes in MAXTRAC´s, but with the "normal" cable, for one radio RX and the other TX, it works like GM 300.

I m going to assemble it all, and make more tests.
but in a quick test running, it works fine.

SALUT

73

 

[jeepsandradios]

The maxtrac and gm300 16 pin is identical with the exception of the fixed or programmable pins.

In theory maxtrac, gm300, m120, sm150, cm300, cdm all use the same pinouts. There are certain ones that are the same on all radios. Only difference is a handful of pins availble to program for active high or low and other functions.

Done what your working on more times than I can remember.

 

[elmanoduarte]

In this MAXTRAC I used same RIB from the GM300, no changes at all!
It work normal, of corse with other CPS.

 

[elmanoduarte]

i have some weeks ago in this forum looking for information about change the front from a GM 300 to this Maxtrac.

I already done it.

In fact it is not same PINS at front, could not be done just by switching...
but i made it by dessemble everyting from the front of the MAXTRAC, and taked the front case from another GM300, and put it all back .

And it works good, because it has same keys, and buttons, everything match.

 

[elmanoduarte]

used a bad Black spary paint.
Normaly i do it fine.
But, it works!

The 1st on the TOp its the VHF,, the other the UHF

The MON yellow Led, its in the midlle in MAXTRAC. In GM 300 its the 1st Led from left sid. But that isnot a problem.