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Motorola Spectra Tac receiver question

Posted: Sat May 24, 2014 2:19 pm
by wb4gbi
Greetings to the brain trust,

I have a micor series repeater that had a problem with its homebrew enclosure, so I purchased a spectra tac enclosure to install back in to the repeater. Here's the problem: The old interface provided a high-going COS (~5 volts) to the controller for COS. After putting the receiver together, and taking it back to the repeater site, I found out the hard way that when using the receiver in carrier squelch mode that there is no high going COS. Pin 11 on the audio control board goes open when unsquelched, and low when squelched. Has anyone used this output (modified or otherwise) to generate COS? Please email off list if you can help. timb447457(at) aol (dot) com. Thank you in advance!

Re: Motorola Spectra Tac receiver question

Posted: Sun May 25, 2014 5:28 am
by Jim202
wb4gbi wrote:Greetings to the brain trust,

I have a micor series repeater that had a problem with its homebrew enclosure, so I purchased a spectra tac enclosure to install back in to the repeater. Here's the problem: The old interface provided a high-going COS (~5 volts) to the controller for COS. After putting the receiver together, and taking it back to the repeater site, I found out the hard way that when using the receiver in carrier squelch mode that there is no high going COS. Pin 11 on the audio control board goes open when unsquelched, and low when squelched. Has anyone used this output (modified or otherwise) to generate COS? Please email off list if you can help. timb447457(at) aol (dot) com. Thank you in advance!



Why don't you add a transistor to the line and make it do what you need.

Jim

Re: Motorola Spectra Tac receiver question

Posted: Sun May 25, 2014 5:59 am
by Bill_G
or a pull up resistor?

Re: Motorola Spectra Tac receiver question

Posted: Sun May 25, 2014 4:38 pm
by N4DES
Jim202 wrote:
wb4gbi wrote:Greetings to the brain trust,

I have a micor series repeater that had a problem with its homebrew enclosure, so I purchased a spectra tac enclosure to install back in to the repeater. Here's the problem: The old interface provided a high-going COS (~5 volts) to the controller for COS. After putting the receiver together, and taking it back to the repeater site, I found out the hard way that when using the receiver in carrier squelch mode that there is no high going COS. Pin 11 on the audio control board goes open when unsquelched, and low when squelched. Has anyone used this output (modified or otherwise) to generate COS? Please email off list if you can help. timb447457(at) aol (dot) com. Thank you in advance!



Why don't you add a transistor to the line and make it do what you need.

Jim
That is pretty much what I had to do to make a spectra tac talk to a home-brew voter that I had over 10 years ago.
The receiver really isn't really COR friendly and it takes some fudging on the bench.