I need a simple DTMF on/off circuit to control a repeater

[mrtor]

Hi Fellow Batlabers

I have a simple requirement (sounds simple to me anyway) of being able to turn on & off a mobile repeater in a vehicle with a DTMF tone.

I need to be able to switch on a back up repeater in the event that the primary repeater is going to fall out of range or needs to pull out of a rolling convoy for what ever reason.

I thought a dedicated frequency (I have plenty at my disposal) with a simply circuit hooked up to a mobile radio (such as a gm300) would detect the DTMF being sent (example 1 for on 5 for off) and would trigger the relay accordingly.

I can't find anything that is commercially available that is that basic and doesn't cost a fortune as funds are limited for the project.

Anyone seen something, a schematic etc that can do this?

Thanks in advance
Michael
Melbourne, Australia

[Will]

What radios are used in the mobile repeater.

Most mobile radios have a DTMF decoder option that sets a relay output. The GM300 will do this.

[psapengineer]

Have you seen this one:

http://www.com-spec.com/selectone/npb/s ... st809b.htm



Regards, Bob

[mrtor]

What radios are used in the mobile repeater.

Most mobile radios have a DTMF decoder option that sets a relay output. The GM300 will do this.

Hi Will

Sorry for the late response, I have been away... I was planning to use 2 x GM300's (1 tx 1 rx) so that sounds like exactly what I need.

Any further clues appreciated.
Thanks in advance
Mike

[mrtor]

Have you seen this one:

http://www.com-spec.com/selectone/npb/s ... st809b.htm



Regards, Bob

Thanks Bob, hadn't found that in my original web crawling.. I will contact them also and get some price details. Will's idea (see above) sounds like it will do the trick for my basic application.

Thanks for the suggestion

Regards
Michael
Sunny, Melbourne
Australia

[HumHead]

Have you looked at the purpose-built vehicular repeaters like the Pyramid SVRs or the Vertex VXR-1000? All of the "PAC-RT compatible" units have an automatic priority resolution scheme that will automatically activate another repeater if the primary unit leaves the scene or goes off the air. No user action is required.

[mrtor]

Have you looked at the purpose-built vehicular repeaters like the Pyramid SVRs or the Vertex VXR-1000? All of the "PAC-RT compatible" units have an automatic priority resolution scheme that will automatically activate another repeater if the primary unit leaves the scene or goes off the air. No user action is required.

Good afternoon

Didn't even know such a beast existed, but it sounds interesting. I'll do a google search and see what I can find out. Thanks for the tip

Regards
Mike

[HumHead]

http://pyramidcomm.com/svr200.html
http://pyramidcomm.com/svr250.html
http://www.vertexstandard.com/indexVS.c ... Archived=0