Hamfest project

[HandiScratchy]

Went to the Charlotte Hamfest today.
I was late getting there and saw a bunch of stuff I'd like to have bought walking out. I did find a Motorola GM300 in the right frequency split so I bought it.
Now I have to figure out how to program it.



I've looked at repeaterbuilder and see some info on rib and RSS etc
Can anyone give me a boost on finding these things in the current Era?
I think I've got a Win95 pc that's still functional and has actual serial ports.

I'm sure I'll eventually read enough to find out but what's going on here?

 

[jeepsandradios]

I use an old DOS toshiba CF25 laptop for my GM/Maxtrac/Radius stuff. USB is not going to work. You can build the cable for about $5.00 in parts but need to find a rib. There were some aftermarket ones at one time. They are a solid radio for a Digi or packet for sure.

 

[PreferredCustomer]

Went to the Charlotte Hamfest today.
I was late getting there and saw a bunch of stuff I'd like to have bought walking out. I did find a Motorola GM300 in the right frequency split so I bought it.
Now I have to figure out how to program it.

View attachment 158083

I've looked at repeaterbuilder and see some info on rib and RSS etc
Can anyone give me a boost on finding these things in the current Era?
I think I've got a Win95 pc that's still functional and has actual serial ports.

I'm sure I'll eventually read enough to find out but what's going on here?
View attachment 158084

You can get a programming cable here:

Motorola GM300 DOS Serial Programming Cable RKN4081 DOS

DOS Serial Programming…

bluemax49ers.com

Programming is through the microphone jack.

 

[a417]

Went to the Charlotte Hamfest today.
I was late getting there and saw a bunch of stuff I'd like to have bought walking out. I did find a Motorola GM300 in the right frequency split so I bought it.

I've looked at repeaterbuilder and see some info on rib and RSS etc
Can anyone give me a boost on finding these things in the current Era?
I think I've got a Win95 pc that's still functional and has actual serial ports.

ebay and the googler, they're out there.

 

[vagrant]

If you're asking about that plug, I use one as well on an old GTX 900 MHz mobile. The jumpers/plug on mine enable the internal speaker as I didn't want to use an external one. Unplug that to get to the good stuff. I probably purchased my programming cable from that same eBay seller linked above "bluemax49ers" as well as other cables from him over the years.

 

[HandiScratchy]

Q

If you're asking about that plug, I use one as well on an old GTX 900 MHz mobile. The jumpers/plug on mine enable the internal speaker as I didn't want to use an external one. Unplug that to get to the good stuff. I probably purchased my programming cable from that same eBay seller linked above "bluemax49ers" as well as other cables from him over the years.

View attachment 158115

Thanks
I found the datasheet for the plug and the pinout. You confirmed my guess about the left jumper enabling the speaker. The 7-9 jumper I didn't really understand.

I ordered the cable. Mark @ Bluemax49ers resounded to my question in less than half an hour (I think it was under 10 mins) so I'd recommend them highly. I went cheap on shipping and chose ups ground so it'll be a few days before I get it.
In the meantime I need to get a power cable which, unless the experts here advise against it, I'll probably fabricate from an SAE battery tender cable and some power poles.

I think I have the RSS but I'm a little dubious about opening the file.

 

[radioman2008]

I bought one of those brand new from a dealer in 1994, for 605$ and that was with the "ham discount."
these are nice little mobiles, great front ends. i used to drive into large city areas and my "ham" radios would be producing alot of Intermod, while my GM300 was quiet as a mouse when no actual signals present.

these program with old DOS based software, the software only worked on old slow dos machines, not windows-based machines with a dos shell.

a common problem with those as they get older......the receiver fails and won't decode anything.

 

[mmckenna]

Q

Thanks
I found the datasheet for the plug and the pinout. You confirmed my guess about the left jumper enabling the speaker. The 7-9 jumper I didn't really understand.

Batlabs is your friend for this older Motorola stuff.

I need to get a power cable which, unless the experts here advise against it, I'll probably fabricate from an SAE battery tender cable and some power poles.

No problem with that. Motorola power cables are cheap, I probably have few laying around, and you shouldn't have any trouble finding them if you wanted to go that route.

I think I have the RSS but I'm a little dubious about opening the file.

Lots of sources for it.

There's a DOS program called Rufus that you can load on a USB drive along with the RSS. I have an old laptop that I set to boot up off USB as first choice. I've used it for years to program older Motorola gear.


I've still got a few of those in use, mostly in off road vehicles running on 2 meter frequencies we use. They were probably 20 years old when I got them, and have been running them another 10 years. They've been rattled all around, rain, mud, dust, and they are still going strong.

One thing I'd recommend:
Ditch the mini-UHF to UHF adapter. The mini-UHF connectors are a weak point on the radio and can snap off easily if hit wrong. It's a good idea to use a short jumper cable with a mini-UHF connector on one end and the connector of your choice on the other. Motorola specifically sold jumpers like that due to this issue.

 

[HandiScratchy]

I appreciate the input so far, I'm eager to see where we can get with this little guy.
I have some old computers. None that predate windows, I do but barely remember dos commands. I think I'll be able to conquer the pc challenges.

On the mini uhf adapter, I grabbed that at the hamfest and felt like it was pretty weak. @mmckenna, I'll take your advice and make a jumper.

This one is actually a UHF range 3 so I think it will get some coax with low loss in the 440 range and N connectors.

Talking to the seller he said it was 16 channel but it turns out to be 8 per the model number. That's more than enough but a little disappointing. I think it was just an honest mistake and only have one repeater in mind for it anyway.

 

[mmckenna]

You can make it a 16 channel with a bit of bit-banging:

GM300/M120

Motorola used RG-142 (I think) for their adapter cables. You just need a short one, I think the Motorola versions were about 6" long. Rg-58 would be just fine for a run that short.

 

[MTS2000des]

One point: these radios are not designed for ham radio "gas bagging". The PA's barely have enough cooling for the specified 5-5-90 duty cycle. In the 90s, before cellphones became cheap and airtime was by the minute. cab drivers loved to use them as CB radios. So much so, the shop I worked at kept PAs in stock as their long keydowns killed them in a few months. A fan is a must if you plan to actually transmit at the typical "ham" duty cycle of 90 percent transmit, 10 percent receive.