Looking for Pinout of Motorola Permacode Filters

Discussion in 'VHF/UHF - 50Mhz and Beyond' started by AD7I, Oct 12, 2017.

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  1. AD7I

    AD7I Ham Member QRZ Page

    I'm trying to use some Motorola Permacode filters (those used in Minitor II pagers) to make my own home-brew two-tone decoder. Does anyone happen to have the pinout for the Permacode filters? These are 4 pin devices and I suspect the pins are Ground, Power In, Audio In and Audio Out. I'm sort of groping in the dark a bit here. I'm also looking for the specific voltage used to power the filter. And finally, what's the expected output from the Permacode filter with the proper frequency input tone: a sine wave at the desired frequency (like a very high Q band pass filter)? or is there a level detector in the Permacode filter so the output is a DC value (i.e, something like low output on correct tone detect and high output otherwise)?

    I appreciate any advice people can provide about these filters.

    Thank you.
  2. K8JD

    K8JD Ham Member QRZ Page

    see if you can find a Minitor II schamatic, should have a pin out for the tone filters on it.
    I sure worked on a lot of those Minitors and Pageboys but so many other kinds of Motorola gear also, that I can't remember much of it. :eek:
  3. AD7I

    AD7I Ham Member QRZ Page

    Thanks John. I've done a fair amount of googling on the subject, but I can't find much. I'm hoping that someone has an old Minitor II service manual on their bookshelf and could send me a photo or scan of the relevant page. Paul
  4. K9STH

    K9STH Ham Member Staff Member QRZ Page

    I will see if I can find a manual on the Minitor, etc. There should be a copy "somewhere" in my manuals library!

    Glen, K9STH
  5. AD7I

    AD7I Ham Member QRZ Page

    Thanks Glen. I'd be grateful for any info you can provide. Paul, ad7i
  6. KD2IAT

    KD2IAT Ham Member QRZ Page

    Batlabs.com has some info on the Minitor II.

    Also, search at radioreference.com and batboard.batlabs.com (separate from batlabs.com)

    And, don't overlook repeater-builder.com as they have all kinds of miscellaneous info tucked away there.

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