Custom Built 220 MHz.
Motorola MICOR Repeaters
by Repeater Builder - Scott Zimmerman

MICOR High-Band mobile converted to 1.25 meter (222 MHz) repeater.

NOTE: Not available on pairs 224T920/223R320 thru 225T000/223R400

Items supplied with basic repeater:
This is a conversion of a mobile radio to a repeater.  A separate receiver RF connection is added to the front panel.
A length of heavy duty power cable (red/black) is supplied for the power cord.  A variety of interface options (DB-9, plain old wire tail, barrier terminal block) are available for connecting an outboard controller.  This repeater can also be built to include an NHRC controller.  The addition of a NHRC controller makes a really nice package and the repeater basically becomes 'plug-n'play'.  No duplexer is supplied.

The MICOR receiver requires modification of the front end helical preselector and other RF stages for use in the 222 MHz. ham band.
This is done using a perfected method by Repeater Builder to ensure sensitivity and selectivity.  Our conversion is very predictable and will result in performance identical to or better than factory stated high-band specifications.  A preamp is not required, but one is available as many circumstances allow for one.  We guarantee our MICOR 220 receiver conversions to have stated factory sensitivity specification; which is .35 uV (-116 dBm) for 12 dB SINAD.  Commonly, our receivers do better than this figure without a preamp, and with a preamp, will result in a squelch threshold that breaks at less than -130 dBm, something below the calibrated range of our service monitors.

We modify the high-band exciters RF circuitry for use in the 222 MHz. band, and eliminate the mic bias.
All filters modified and retuned.
We change the Power Amplifier board as the highband units are not easily converted to 220, as the transistors don't deal with that high of frequency well.  We build a totally new PA using a Japanese power amplifier module that is properly bypassed, coupled, and heatsunk.  This ensures spectral purity and efficiency.

The information in these sites would be used to convert the radio to 220, full duplex:
MICOR repeater conversion.
MICOR 220 conversion.

The repeater will require a 20 amp Linear power supply or equivalent just to run the repeater.  If an add on RF Power Amp is going to be used, please allow for the additional current consumption accordingly.  Astron's are good because of their over-voltage protection.  We don't recommend switching supplies on repeaters.

  • Price below include items in the "supplied with basic repeater" list above
  • Basic MICOR Mobile radio, converted to 25 watt 220 - 225 MHz. repeater $800.00
  • All sales subject to the Terms outlined in this linked page.

    Options: (If you don't see your option listed here, e-mail us for pricing and availability!)
    We also convert user supplied radios.
    You can deduct $50 from the stated price of the repeater as referenced above if you ship your working radio (with Channel Elements) to us for conversion.
    Thanks for your interest in our custom built repeaters.  Let us know if we can help you out.

    Scott @ (814) 444-9460
    (Weekdays during normal business hours)

    or email Scott at:
    Email Scott

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    Last updated: March 4, 2010