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Motorola i500 junction box?

Posted: Sat Jun 14, 2014 5:06 pm
by Farmboy
I bought a pair of used Mack trucks out of the same fleet. They had these i500 junction boxes installed. part number FLN 2799a. The box works a remote speaker, a remote PTT button, and a remote mic. Is there any way to interface this with a CM200 radio. I tried using a cat 5 cable to connect the back of the i500 to the mic outlet on the radio, but it just started to transmit continuously. I would love to use these if possible. Or some kind of a voice actuated headset.

Re: Motorola i500 junction box?

Posted: Sat Jun 14, 2014 6:48 pm
by Jim202
Farmboy wrote:I bought a pair of used Mack trucks out of the same fleet. They had these i500 junction boxes installed. part number FLN 2799a. The box works a remote speaker, a remote PTT button, and a remote mic. Is there any way to interface this with a CM200 radio. I tried using a cat 5 cable to connect the back of the i500 to the mic outlet on the radio, but it just started to transmit continuously. I would love to use these if possible. Or some kind of a voice actuated headset.


Sounds like you either had a wire connected wrong or the CAT5 cable was pinched and shorted causing the PTT to key up the radio.

My first suggestion would be to make sure you know what pins on the mic connection is ground and PTT. Then go back to your junction box and find the PTT and common ground. Then work on the speaker connections. Make sure you don't ground either of the speaker wires. Last is the mic connection. You will have to key the radio to test the mic connection. So that is why I do it first to get over the hard part of identifying all the connections.

Jim

Re: Motorola i500 junction box?

Posted: Sun Jun 15, 2014 7:33 pm
by VE3HKB
It sounds like you plugged a CAT5 cable into the mic jack of the FLN2799 and the mic jack of the CM200. Without the schematic for the FLN2799, it would only be an educated guess that you grounded the CM200 PTT input.

The FLN2799 audio box is pretty much useless without the matching FLN2798 cradle and I500 or I700 iDEN portable. This in-car kit was designed to provide external mic, ptt to the portable, and amplify the RX audio for an external speaker (and a serial port). With the appropriate portable, you would get simplex audio in dispatch (radio) mode, and pseudo full-duplex (TDD) in interconnect (phone) mode.

While it's possible that with some creative re-engineering you might be able to make the box work with a CM200, you're likely better off just connecting your speaker, remote mic and PTT to the accessory connector (P1) of the CM200. You won't get anything more than what the CM200 would provide (i.e., no VOX operation, which the in-car kit did not provide anyway).

Howard