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Zetron ZR350 - using as a basic repeater with GM300

Posted: Wed Dec 11, 2013 12:57 pm
by g8tzl2004
I have a Zetron ZR350 telephone interconnect box which is designed to be used with GM300's.

I have downloaded the manual from the Repeater Builder site and spent a good few hours researching.

The ZR350 can be used to patch a telephone line with a single GM300 radio or to build a repeater using 2 GM300's.

I basically just want to build a very basic repeater and occasionally use the telephone interconnect feature.

Reading the manual, if you want to do a "radio to radio" repeater type link, you need to use the DTMF on one radio to dial up the ZR350 and then input the "number" of the radio you want to call. This is all to complicated for a 2 radio system. I just want to press the PTT!!!

Does anybody know whether the ZR350 can be used to act as a very simple repeater rather than a more complex DMTF selective call repeater?

Thanks

Re: Zetron ZR350 - using as a basic repeater with GM300

Posted: Wed Dec 11, 2013 3:50 pm
by Bill_G
Got a link for the manual?

Re: Zetron ZR350 - using as a basic repeater with GM300

Posted: Wed Dec 11, 2013 4:03 pm
by g8tzl2004
Its on the Repeater Builder site.

I don't know how to post links!!! Google "Repeater Builder ZR350" and you will instantly find it - there is lots of useful Zetron PDF files on the Repeater Builder site.

Re: Zetron ZR350 - using as a basic repeater with GM300

Posted: Wed Dec 11, 2013 9:24 pm
by Bill_G
There's an URL button at the top of the reply screen. Click it, and it will throw a pair of bracketed URL and /URL that you paste a link between.

Reading the manual, it looks like you're right. It's a radio to radio telephone call with fake dial tone and everything. You can call Zetron. Their tech support will tell you if there is a way to make it a plain old repeater controller. But, it looks like it's a telephone interconnect that can also do paging, quick call, and patch calls between radios. There was a time when this had an application. When you don't want to listen to all the other traffic on the channel, this gave you quasi-private call between units, and allowed people to call you on the radio from a phone. A little clunky, but it worked.

We had something like this for the pipeline to create a wide area network. You brought up the tower (dial tone), dialed the number to the repeater you wanted to talk out of, wait for it to answer, and then punch in the code of the guy you wanted to hail. If his radio heard you, it transponded back with a tone, and then you waited for him to pick up. If no activity occurred for two minutes, the link dropped. You could keep it alive for an additional four minutes or so by saying something (HEY BOB! YOU THERE?). Somewhere around 8 minutes it dropped automatically to keep the long distance charges down. If his truck didn't transpond, then you knew he was out of range, or turned off, and maybe try another tower.

Cellphones made all that pointless.

Re: Zetron ZR350 - using as a basic repeater with GM300

Posted: Thu Dec 12, 2013 3:08 pm
by g8tzl2004
Thanks for the info. I guess I might be able to program the DTMF access sequence onto a call button or double press the PTT??

Anyway, its an interesting project!!

Re: Zetron ZR350 - using as a basic repeater with GM300

Posted: Thu Dec 12, 2013 4:14 pm
by Bill_G
You're welcome. It is what it is. Call up Zetron. See if they can help you.