Notes for MICOR Base station and repeater station conversion

By M. Scott Zimmerman N3XCC

*Disclaimer: The following are notes ONLY. This is not intended to be a complete how-to guide. I have used the following guidelines on every station I have done and they seem to work fine, however use them at your own risk.

Normal Backplane

Jumper Line driver pin 13 to line driver pin 23 with a 100k resistor to enable local speaker monitor audio. This audio level can also be adjusted with the pot on the audio/squelch module, however this *may* also adjust the audio level available to feed your controller. (See connections below)

DVP Backplane TCN1264, TCN1273, etc.

Jumper Line driver pin 6 to line driver pin 19 with a 100k resistor to enable local speaker monitor audio. This audio level can also be adjusted with the pot on the audio/squelch module, however this *may* also adjust the audio level available to feed your controller. (See connections below)

All Backplanes

If using keyed Tx channel element:

Do the mods to the station control module TLN4635 or TLN5970 under "keyed channel element".

Jump J5-14 to J5-19 for Keyed F1 Transmit element enable.

If not using Keyed Tx Channel element:

Jump J5-19 to GND for constant F1 Transmit element enable.

Ground J2-30 for F1 Rx enable. Ground can be found on pin J2-26.

A monitor speaker can be connected to pins J2-1 & J2-2.

Repeater controller connections

Connections to your repeater controller can be made in several different ways. I prefer using the signals available at the Squelch gate module location. I simply solder a pigtail umbilical cord to the appropriate pins of the squelch gate module and put an appropriate connector on the other end of the cable. It's a very simple interface.

• PL Encode - A PL encode tone may be connected to J2-16

• Discriminator audio - Buffered discriminator audio is available at J2-15

• Controller audio - A source of de-emphasized, buffered, PL filtered (If OEM decoder is installed) and squelch gated audio is available at J2-14 or Squelch Gate Module pin 17. CAUTION: This audio goes through the above mentioned pot on the audio/squelch board. If you use this audio source, set the Max. volume level before setting your controller's Rx pot. I normally use the 100k series resistor and turn the A/S board pot wide open. In doing this, I am providing the controller with as much audio as possible to help eliminate noise. If you wish to run a differing audio level, set this pot for your desired audio level.

• PTT - active low Push-to-talk logic is available at Screw terminals 12 & 8 and also at Squelch gate pin 18

• Ground - Ground is available on most of the chassis. Screw #1 is ground, as well as Squelch gate pins 1 & 23.

• 12v - A source of 12V is available at screw terminal #10 and at Squelch Gate pin 12.

• COS - An active high COS is available at Squelch Gate pin #5 and J2-13. You will need to build an inverter if your controller requires active low COS logic.

• CTCSS decode - If an OEM decoder is being used, active high CTCSS logic is available at Squelch gate pin 14 and at J2-10. CAUTION: This pin is driven high on an active signal. Use a series resistor to prevent an accidental short from burning out the transistor on the decoder board.

These notes were prepared by M. Scott Zimmerman; March 6, 2006
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