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Making a Repeater....

Posted: Thu Jul 29, 2004 1:24 pm
by Larry
Anybody know if there's a kit to convert 2 Maxon SM-4450 radios into a repeater?

I've seen complete setups already to go. I've got 2 brand new Maxons still in their box that I'd like to make a repeater out of... anyone know of a way that this can be done?

Thanks for any suggestions

Posted: Sun Aug 15, 2004 7:55 am
by olderookie
no but I am thinking of doing it as well I have 2 radios and am looking a a zetron controller and as I type looking for a duplexer to add to the mix

Joe

Posted: Wed Aug 18, 2004 12:09 pm
by 440roadrunner
I'm certainly no bench tech, but here's how I did mine with two GE monograms (same as SM-4450) in a little amateur remote setup, and using a Zetron 37

Remove the many screws from the big shield in the bottom of the radio, you can thread the power cord right through it without unsoldering.

Viewing the radio bottom, with the front panel toward you, I got the squelch signal off the small, vertical squelch board near the front. If you look carefully, on the end toward the display side of the radio, there is R19, D6, and R18, in a row from that side of the board. I picked off squelch at the end of D6 toward the motherboard.

Then, toward the rear of the radio and just a little to the right, is Q7. I picked unsquelched audio off the R37/Q7 emitter

I picked off power at the obvious point where "big red" comes in.

Thread the wiring neatly through holes in the bottom shield, and reinstall. I was able to drill a neat hole just to the bottom of the mike connector for entrance of the wiring.

In the case of the transmitter, I simply used mike input. The zetron seems to be able to handle this ok.

In my case, I'm also using the stock receiver decode/audio out for another purpose, so be aware that you'll have to build a jumper for the mike plug to ground pin3 (hangup) at the mike jack.

I just happened to get a number of these REAL cheap, and later found some 2 meter amateur capable mobiles almost as cheap (and beat up) on eBay.