GR500 upgrade question

[scottp1111]

Hello,

I have a GR500 repeater currently loaded with hln3333b repeater Rick controller and two gm300 VHF . I am now upgrading the system to 12.5 compliant CDM 750 radios. Can I simply just replace the radios plug in the accessory connector area and be done? The radios are programmed. Radio one is my tx radio setup radio two is Rx radio setup to receive.

Is there anything that needs to be done to convert from gm300 to CDM series ? Everyone feel free to comment....

 

[SteveC0625]

The CDM's don't need the speaker jumper (Pins 15 &16 on the accessory connector) so be sure to remove it.

The mic connector on the CDM's is a 10 pin RJ50, not an 8 pin RJ45. If you use the standard
RJ45 jumper (pins 3&4 - keeps PL on hook) you run the risk of damaging the mic connector on the CDM's. Best to find some RJ50's and make your own shorting plugs.

 

[scottp1111]

Do I have to have the mic shorting plus ? The gm300 s have them in there. The gm300s speakers are not currently working any thoughts

 

[scottp1111]

Oh! Ok I did some further reading now I understand. Can't I just leave there mics plugged in and hidden in the case and get the desired results

 

[SteveC0625]

Oh! Ok I did some further reading now I understand. Can't I just leave there mics plugged in and hidden in the case and get the desired results

That will work as long as they are hung on mic hangers that are grounded to the same ground as the radios. Otherwise, PL is disabled and the repeater won't work properly.

I think you will really like the CDM's. They're easy to program and rugged as can be. I have used a CDM for quite a while in my own truck for EMS responses and I could not be happier with it.

Edit: On the speakers, the PO may have unplugged them inside the control head of the old radios. I am kind of old-school when it comes to things like that and would just leave them hooked up and turn the volume down all the way..

 

[scottp1111]

Yehi got two CDM 1250s in my truck one VHF one low band. I like them a lot. Where can I find two of them mic shorting clips for CDM s

 

[SteveC0625]

Yehi got two CDM 1250s in my truck one VHF one low band. I like them a lot. Where can I find two of them mic shorting clips for CDM s

I have not found a commercial source of them yet.

But check with mre1032 on Ebay. He offers the RJ45 jumpers and may have the RJ50's, too.

 

[scottp1111]

Just sent him an eBay email requesting a set...thanks bud

 

[ramal121]

Another quirk to consider on the CDMs is they will not power up by themselves after a complete loss of power. This is regardless of whether the ignition sense has been programmed and utilized or not. You can see this by switching the power supply off, then back on.

The only way to get the repeater to come alive after a power failure by itself is to have the emergency jumper in place between pins 7 and 9 of the accessory connector of both radios.

Oh, and I believe the 8 pin shorting plug will plug into the 10 pin CDM mic jack and center itself correctly and ground the hook line. Motorola supplied them with the GR repeaters but I don't have a PN. I make my own with a RJ-45 and a hunk of wire.

 

[scottp1111]

Great info! I need to surely do that. Even though my repeater has battery backup installed it still powers down during the swap from AC to DC. .5 second power loss. Wow great info. How can I install that jumper considering the HLN3333B cables come from the controller straight into the radios...

 

[ramal121]

Last time I did a CDR repeater (with CDMs and a RICK) either one radio powered back up or neither did, can't remember which. The idea is to take pin 9 (emergency input) and ground it. Pin 7 is ground. Needs to be done on both radios. Now the factory cable may have a wire inserted into pin 9 and it goes back to the RICK but I don't think it grounds out unless the third accessory shorting plug is in and then I think it only does one radio without modifying the RICK. Anyway, a hassle. I remove the cable wire from pin 9, insert my own and ground it on both to pin 7 by splicing into the wire that is inserted there. Actually, any ground would work including the power supply.

Sounds like you need a little help. Can you PM me with a mailing address? I can send some vital stuff.

 

[WB0VHB]

There has been some misinformation in the replies to this post.

You do NOT need to install the mic jumper plugs in a CDM. Just program the radio not to go into monitor when off hook. This is located in RSS under Radio Configuration and the Basic tab.

Don't mess with the mic connector by plugging your own jumper! But you can install a microphone in the transmitter in case you need to transmit locally.

The pin 7 and 9 trick works fine when a CDM is used just as a mobile. However when used as a repeater, those pins already have wires installed. You could cut those wires and jumper them but I just add a wire to Pin 10 of the RICK accessory connector. Connect that Pin 10 wire to B+ or your power supply and the radios will power up when power is applied to the main power connector.

The CDM RSS has a easy feature that allows the accessory connector to be setup as either a RICK receiver or RICK transmitter. Just go to Radio Configuration / Accessory Pins and select the correct Accessory Package from the drop-down menu.

If you can find a copy of the CDR500 \ CDR700 manual, it details how to setup the RICK and each CDM mobile for proper operation.

Randy

Hello,

I have a GR500 repeater currently loaded with hln3333b repeater Rick controller and two gm300 VHF . I am now upgrading the system to 12.5 compliant CDM 750 radios. Can I simply just replace the radios plug in the accessory connector area and be done? The radios are programmed. Radio one is my tx radio setup radio two is Rx radio setup to receive.

Is there anything that needs to be done to convert from gm300 to CDM series ? Everyone feel free to comment....

 

[SteveC0625]

Oh, and I believe the 8 pin shorting plug will plug into the 10 pin CDM mic jack and center itself correctly and ground the hook line. Motorola supplied them with the GR repeaters but I don't have a PN. I make my own with a RJ-45 and a hunk of wire.

It will fit, and it will properly short 3 & 4, BUT the wider plastic edges of the RJ45 can damage pins 9 & 10 of the RJ50 female on the CDM to the point that the connector needs to be replaced. Those that have suffered this fate have cautioned strongly against doing so because of the difficulty of replacing the connector in the CDM. This is well documented on both the batboard and batlabs.

At least one other poster in this thread has also said, "Don't do it!"

 

[SteveC0625]

There has been some misinformation in the replies to this post.

I did not intentionally try to give out misinformation. So few people post any responses to these questions that I offered up what I have in my notes to the OP.

All the info offered by you and others in this thread will now be in my notes when others ask the same questions.

Thanks for giving some good info.

 

[cmdrwill]

The Motorola R.I.C.K is a nice product but it has several shortcomings. The ID-O-Matic II not only gives you the necessary CW ID, but it also processes audio and has all the timers you'd need for making a repeater with a pair of MaxTrac, Radius, GM300, or CDM mobile radios. This article shows some circuit improvements and how to wire the accessory connectors.

http://www.repeater-builder.com/maxtrac/files/id-o-matic-rick-rev2.pdf

 

[ramal121]

Thanks for giving some good info.

And thank you. This is how we all learn...