On Mar 15, 2010, at 11:33 PM, Russell wrote: > Hi, I am building a portable repeater for our ARES Club. > I have 2 Icom IC-2200H 2 mtr units, a ces rm-10 controller. > I am new at this building, and cannot decipher the info > given by the controller instructions.
It will help if you'll tell us which controller it is. > It advises to use the radio cor connection and here is where I'm > stumped. A COR is any logic signal inside the radio that triggers when either the squelch is open, or probably better, whenever CTCSS is detected (if you're requiring CTCSS on your repeater). Some controllers take inputs for both as separate signals and let you then turn on/off the requirement for CTCSS in the controller by choosing which logic input to trigger off of, or my preference, logically AND'ing the signals together, meaning both COR/COS and CTCSS must be active from the repeater's receiver before the repeater will repeat. This signal, as in on most Amateur grade gear, is NOT available on any of the connectors of the IC-2200H, per the manual at http://www.icomamerica.com -- pages 1-5. The only way you'll find it is with a logic probe, oscilloscope, or similar and knowledge of the radio's schematic and internal layout, and you'll have to "bring it out" from inside the rig. There are MUCH easier options for this, including... - Use of the commercial Icom rigs. They have appropriate programming software and connectors for interfacing them to external hardware. - Maybe consider talking to the sponsors of this mailing list... Repeater-Builder The Company (TM? GRIN...) -- they make much higher quality repeaters out of older commercial gear than can be easily cobbled together from a couple of Amateur-grade mobiles. They can also discuss duplexer options, see below for more on that. > It also wants a connection at the output of the discriminater > circuit. A Discriminator circuit can be found in any FM/PM radio, it's the audio prior to being de-emphasized directly off of the circuit that detects it from the RF input. Most controllers will also work with "regular" audio from a speaker or better, some place in the radio that gives a constant audio level. (If you use the speaker circuit, someone might walk up and turn down the volume control and mess up your carefully set levels that provide correct deviation on your repeater transmitter that matches the deviation of the FM signal being received.) Again, need to know which controller you chose for your engineering project, and why... > I have been a tech over 35 years, this issue is causing my teeth > to fall out, I already lost most of my hair. Ahh, don't go that far. It's just a repeater! (GRIN) > I would really appreciate any help you might have. > 73==Dan w2rdt > > BTW: I know these are not the best units to work with. > Financially right now, it is all we could afford. My bigger concern is, "Why 2 meters?" -- getting a duplexer that can handle a standard ham radio 600 KHz RX/TX split small enough to be "portable" is a pain, unless you're going to run a VERY low power level. You might have to look into doing a very non-standard and much wider split. This is why most people building "portable" repeaters are doing it up at UHF where the standard split is 5 MHz... Also if you haven't been perusing the Antenna, Duplexer, and other areas of www.repeater-builder.com -- definitely check those out. This "I want to build a portable repeater" question comes up so often, I wonder if someone has time to turn it into an article for RB... -- Nate Duehr, WY0X n...@natetech.com