Motorola accessory pinout

[Ronin055]

Hello all, this is my first post here. A friend of mine who is a radio tech, directed me here to find some information for a project Im working on.

What Im trying to do is create an adapter connection for an HT440 radio. Im trying to cross over into a Motorola t7400 connection so that I can use a variety of headsets for my HT440.

So I have the HT440 pinout guide for the connection into the radio. And I have several of the connectors.

Now what I need to know, is the wireing to the female jack on the T7400 so that I can wire it into the connector for the HT440.

This should enable me to connect any single pin motorola heaset or accessory to the HT440 and still utilize a remote PTT.

Thank you for your time.

[Ronin055]

Well I guess no one knows the answer.

Can you suggest where I might find this information?

[Will]

Problem is the "T7400", we never had or used them.

I can get the pinout for the HT440 to the PTT BOX made by Ralston, seeing as most Ht440s are gone by the wayside now. The PTT BOX has the 2.5mm three cond. jack and takes most Cellphone headsets.

Ralston still makes them for GP300 style connectors.

[HLA]

isn't the t7400 the toy radio that motorola makes that you get at radio shack or best buy? why would you want to use a toy headset on your radio?

[Will]

"So I have the HT440 pinout guide for the connection into the radio. And I have several of the connectors. "


Ok then, The connector that fits the HT440 cable:

Pin 2 the large pin goes to the middle connection on the 2.5
mm jack, called the ring.

Pin 3 goes to the sleve or frame/gnd of the 2.5 mm jack
Pin 1 goes to the tip of the 2.5 mm jack
Pin 4 goes thru a PTT switch, norm open other side of the
PTT switch to the frame of the 2.5mm jack.

Most any cellphone headset plugs into the 2.5mm jack.