Thanks Nate, we are using radios at hand. we are a new club and are ARES in 
this county.
I am building this unit just for call outs. We are using 2 mtr mainly due to 
not much activity
on 70 ctmrs. I have built some cu copper 2mtr loops, I cannot believe the 
performance
these little loops give out. Everything about this portable repeater is an 
adventure, I have
hand made just about everything in this system. The cabinet has locks to keep 
wondering
minds, dual fans, and a set of 100 amp gel cell batteries thrown in for power.
Will always be with my truck, so I have power there as well.
Your input is greatly appreciated.
I will be sure to send back a report on how this works, or if it does not work.
73 russell
w2rdt
 I look to the future because,
that is where I will spend the
rest of my life. 




________________________________
From: Nate Duehr <n...@natetech.com>
To: Repeater-Builder@yahoogroups.com
Sent: Tue, March 16, 2010 3:20:48 AM
Subject: Re: [Repeater-Builder] cor location in an ic-2200h

  

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





      

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