At 09:52 AM 3/6/06, you wrote: >Hi all, >I will be interfacing a RC-210 to a Micor Compa-Station unified chassis >arrangement in the near future... > >I am sure a number of you have accomplished this task already and I am >looking for hints to accomplish this as "cleanly" as possible. I ain't bad >with RF-stuff... but Micor logic has never been my strong point. Any hints >as to where to pick-up discriminator audio, cos tos and re-inject audio >would be most appreciated. I would like to retain as few cards as possible >just for simplicity sake. > >TIA! > > 73 >Mike Perryman >www.k5jmp.us
I've converted several Micor stations to amateur repeaters and found that this mod is the most complete and usable. <http://www.ccdx.org/zedyx/mods/micorbas.htm> I make two changes from Joels mod: 1) where he uses a wire jumper from J2-6 to J2-14 I route both sides to a rotary switch (there's a position for one under the volume and squelch controls of the unified chassis) that allows me to use the Micor audio amp and speaker to monitor several sources. 2) Joel's mod uses a FET to key the transmit channel element (Moto leaves it running full time). I skip the extra FET and use the switching transistor that was intended for the antenna relay. Other folks jumper pins on the line driver module but I prefer this method as it makes the speaker level independent of the audio level fed to the controller. In two of the stations were shipped as DPL models and required changeover to tone PL. There are two different PL decoder boards, one has more pins than the other and they aren't interchangeable (5 and 7 pins if memory serves me). Naturally my junk box and the junk boxes of all of the usual local suspects didn't have the right one... (hello Telepath in San Jose,Calif). There is a metal bracket that mounts the PL decoder board to the receiver chassis and it's different than the one that mounts the DPL decoder. Yes, you can support the PL decoder board on the pins alone, but it would not have survived the 4x4 road up to any of our sites. As I was ordering parts from Mother anyway, adding a $2 for the bracket didn't break the budget. This was many years ago, the bracket may not be available any longer or may have gone up in price. The alternative is to support the card on the pins while in service but remove it before transporting the chassis. The squelch control was not hooked up in three of the stations and it required removing the horizontal interconnect board to add a jumper (maybe two or three, I forget). Moto assumes that a station that lives behind a DPL decoder 24x7 does not need a working carrier squelch. Since we wanted a COR controlled PL encoder we didn't bother locating or installing the appropriate real Micor PL encoder as it is tightly slaved to the exciter. I had a TS32 left over from a previous project so we used that as a main channel transmit encoder (there is a pin on the transmitter interconnect row for PL injection) and it worked fine. The Scom 7K has an audio gate specifically designed for switching the PL encoder tone on and off and we routed the TS32 encoder (which was strapped to run full time) through the audio gate to the transmitter. Physically the TS32 is located in the control receiver chassis as we initially used its audio filter on the control receiver. We also hooked it up the TS32 to the PL frequency control pins on the Scom 7K with a length of ribbon cable. Just leave all the frequency switches on the TS32 open and solder down 5 wires to them plus a 6th wire as ground. These days I'd use a TS64 and hook up the reverse burst. All that was available was the TS32 so we programmed the delays in the 7K to mute the PL encoder then wait 200ms then drop the PTT. The PL roll off audio filter in the TS32 leaves a LOT to be desired... once we replaced the factory control receiver with a factory PL version everyone could hear the difference between the TS32 PL filter and the "real" receiver. We now use the TS32 filters as a last resort. The Micor has a provision for a local microphone to plug into the unified chassis and it is mixed into the transmitter audio along with the other audio sources. Make sure that the TX levels are set so that the microphone is at "normal" levels, and then adjust the controller levels to match. In addition to the audio selector switch mentioned above we added a clearly labeled 4PDT "transmitter takeover" mini-toggle switch between the controller and the micor chassis: the 1st pole is in transmitter audio, the 2nd pole is in the transmitter PTT lead, the 3rd pole is in the PL encoder and the 4th pole (only there because we didn't have a 3PDT switch in the junk box) is a super-bright red LED... Down is normal, up is local microphone only (all the toggle switches in the cabinet except the power switches are wired so that down is normal. Just one more zero-cost layer of idiot proofing. A quick glance at the switches before closing the rack door verifies that nothing was left disabled. On our systems all interfacing between the Micor chassis and the "outside world" is through the TB3 screws at the left edge. There are a few extra screws and we used one for the transmitter PL input. Every useful signal plus all the extra screws are wired into a DB15 pigtail we installed - a DB15 plug and a foot of cable, and stripped the outer jacket back to about 6" and cut the 6" conductors to length as we crimped then soldered solder lugs to the wires. If we ever need to remove the unified chassis from the rack we unplug one DB15 pigtail cable plus all the stock motorola wires and that's it. Enough of a brain dump for now, I'll post another one later if I think of anything. Mike WA6ILQ Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
