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KE4NYVJR wrote:I have a crummy repeater I built up using two GM300's, strapped together in the most simple form to create a repeater. It has been running for over a year without a problem, good audio too. However, I wanted to add a tail, ID and courtesy tone, so I picked up one of the new ID-O-MATIC III kits. Kit went together fine. I got everything wired up and I have good COR detect/keyup and I do have the courtesy tone (kind of low, but works), but my transmit audio is barely audible. I did some searching and came across this document on modding the ID-O-MATIC II for use with GM's: http://www.repeater-builder.com/motorol ... k-rev2.pdf
However, it refers to modding the II that also has an on-board LM386 op amp. They did away with the op amp on the III, so this document is sort of useless to me. I did print out both schematics and tried to make a comparison, but since the op amp is no longer used, it's a whole different audio pass scheme (from what I can tell).
I did a quick test by leaving the ID-O-MATIC III tied to the COR ground and power and removed the RX audio and TX Audio lines. Tied them back together (like the old configuration) and I got my good loud audio back. The audio is obviously being attenuated in the ID-O-MATIC III.
Just wondering if anyone else has tackled this yet. We might have a used GR300 coming soon and I would like to pull it's RICK out and replace it with another III, if I can get it working correctly.
Will wrote:In the interim, Wire the RX Radio's audio directly thru a 2.2 K resistor and a 2.2uF capacitor in series to the TX radio's mic input, capacitor's + towards the TX radio mic input.
The ID-O-Matic pin 11 thru a 6.8 K resistor to the TX radio mic input.
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