8 Pin microphones and the CDM radios

[SteveC0625]

I just received a couple of CDM750's. One came with the standard CDM microphone with the 10 pin RJ style connector (AARMN4025.)

The other came with an 8 pin RJ connector. This mic is the HMN1056 which was used on the Radius/Maxtrac radios.

I am finding conflicting information about using an 8 pin mic in the CDM's. Several sources say the 8 pin Radius/Maxtrac mics work just fine in the CDM's, but then I find this warning over on repeater-builder.com:
NOTE: The CDM series is the current replacement for the Maxtrac / Radius / GM300 line, and at first glance you'd think that a Maxtrac microphone will fit. Yes, it will but you won't like the results and you WILL be sorry. The CDM uses a 10 pin RJ-style mic jack, where the Maxtrac uses an 8-pin. Yes, you can force a 8-pin plug into the jack, but the outer ridges of the plug will mangle the outer two pins of the 10-pin jack. The odds are 9 in 10 that you will end up replacing the 10-pin jack, and it's not an easy fix.

So which is the better advice? I'd really like to use the HMN1056 or, even better, the HMN1035, but don't want to break anything in the process.

Thanks!

 

[fineshot1]

That warning on repeater builder is there for a good reason.

If you put the 8 pin and 10 pin mic plugs next to each other you will notice
that the maxtrac mic 8 pin plug has plastic ridges in the same spot that
the CDM mic plug has its pins 9 & 10(the outer two pins).

That plastic ridge on the maxtrac 8 pin mic plug can do physical damage to
the CDM mic jack pins 9 & 10 and possibly others if the pins get pushed out
of alignment and possible shorting issues can ensue as well.

Wiring wise the two are compatable but physically they are not and you can
push a maxtrac 8 pin mic plug into the CDM mic jack hense the warning.

 

[davidgcet]

it will work fine as far as the mic is concerned, but it will damage the outer pins. so you have your choice of using the correct mic, or paying a lot of money to fix then jack every now and then. how often it will have to be replaced would depend on luck and how much the cord is wiggled around. i have a bank of CDM control stations off a console and use a 1056 as a local test mic, been fine for 10 years now. but during that time the mic has only been plugged into each radio maybe a dozen times and is never left plugged in. on the flip side, i have customers who have swapped mics over and ruined the jack in under a month!

 

[SteveC0625]

fineshot1 & davidgcet:

Thanks to both of you for good answers.

Plan B might be to create an adapter. Anybody know of such a critter that already exists?

 

[fineshot1]

fineshot1 & davidgcet:

Thanks to both of you for good answers.

Plan B might be to create an adapter. Anybody know of such a critter that already exists?

Your quite welcome and thats a good idea but i'm thinking your gonna have to make one.

 

[SteveC0625]

Your quite welcome and thats a good idea but i'm thinking your gonna have to make one.

I am thinking that one of these guys:

wired to a RJ50 male should do the trick.

If I can't get my hands on a properly wired RJ50 male, I can either get a wiring kit for the accessory connector and go in through the back, or I think I have found someone who can actually make up a custom RJ45 female to RJ50 male.

I really want to use the HMN1035 for my own install. Call me sentimental, but the old style, traditional "fill your hand" Motorola microphone just works best for me. And I think it was the best looking mobile microphone from any manufacturer, ever.

 

[gmt0000]

If you like the 1056 mic, why not just crimp a 10 conductor modular on the 1056 cable, leaving the outer 2 conductors empty........

 

[SteveC0625]

If you like the 1056 mic, why not just crimp a 10 conductor modular on the 1056 cable, leaving the outer 2 conductors empty........

Doesn't that require a special (read expensive) crimping tool?

 

[N4KVE]

Boy am I glad I just read this thread. I am in the process of installing a MCS2000 in my car. The control head has the 8 pin jack, & yup I was going to use a AARMN4025 [CDM mike with a 10 pin plug]. I'll use a 8 pin HMN4049 mike instead. GARY N4KVE

 

[KG4INW]

Doesn't that require a special (read expensive) crimping tool?

I was thinking the same thing, that is adding a new connector but yeah, they're not the cheapest but not too bad either. It comes down to how often you'll use it. Amazon.com: Paladin Tools 1345 RJ50, 10P10C, 10 Pin 1300 Series Crimper: Home Improvement

 

[fineshot1]

I was thinking the same thing, that is adding a new connector but yeah, they're not the cheapest but not too bad either. It comes down to how often you'll use it. Amazon.com: Paladin Tools 1345 RJ50, 10P10C, 10 Pin 1300 Series Crimper: Home Improvement

Its like anything else - if ya dont have the right tool then consider paying someone else to do it.

If your gonna change the oil filter on the engine of your car then you need an oil filter wrench.

Same concept for working with antenna cables and connectors.

If you have the right tools they eventually pay for themselves in the savings of doing it yourself.

 

[KG4INW]

Exactly!