Cross Band With a Maratrac

[ASWEEZY]

Hello all

I was contacted today about a project requesting a lowband Maratrac to be cross banded with a CDM1550 VHF using a rick type interface. The person I normally (kurt@MRE) buy the repeater interfaces through says that this can not be done. He said the the Maratrac does not have carier detect is this true and is ther eany way to make this work?

[Wile E. Coyote]

I have seen a Maratrac used as a base station once a long time ago. You are right, they do not readily provide COR. They found a spot on one of the PC boards to tac a wire on to and ran it out of the housing through a small hole that was drilled into it.

Unfortunately I do not have documentation for the Maratrac any more.

But to answer your question, Yes- it is possible, but it won't be easy.

WEC

[motorola_otaku]

Go to Repeater Builder and download the Maratrac service manual. Mic audio, PTT, ground, and handset audio/RX audio can be pulled off the interconnect board.

You can use the busy light line as an active-high COR, or since the radio runs off a normal 5-pin Maxtrac logic board you can derive active low COR off it:



Obviously you won't be routing the signal to the front header as shown here, but you get the idea.

[ASWEEZY]

Go to Repeater Builder and download the Maratrac service manual. Mic audio, PTT, ground, and handset audio/RX audio can be pulled off the interconnect board.

You can use the busy light line as an active-high COR, or since the radio runs off a normal 5-pin Maxtrac logic board you can derive active low COR off it:



Obviously you won't be routing the signal to the front header as shown here, but you get the idea.

Would you be able to explain this a little more in depth. If I do this it ould be my first time and I am very nervous about it.

[ASWEEZY]

The way I read it Pin 9 drives the Busy LED and the Squelch Knob. If I tap into that and put it to pin 2 on the programing jack I should have everything correct? Also would this work because the radio is a low band with the squelch knob and all channels are carrier squelch.

[jbick]

I am trying to set a motorola m100 (5 pin radio) to have Active LOW COS. I was able to located the pin that does have a COS, however, I need active low, rather than active high. Any recomndations?

[Wile E. Coyote]

Have you thought of wiring a PNP transistor in line to invert the signal? There is a great article about how to implement them here:

http://www.rason.org/Projects/transwit/transwit.htm

Good Luck!
WEC