Re: help with the COS on a Motorola M120 and a PiRLP Node

Butch Bussen

Node 3148
Wallace, ks.

Thanks much. I'll forward to Mike. On Fri, 4 May 2018, Teton Amateur Radio Repeater Association tarra@... [irlp] wrote:

Some more information would be helpful. Is it an 8 or 16 channel radio? If it is a 16 channel radio, how is pin 8 programmed? And are you using pin 8 for the COR? I sure wouldn't be trying to measure with an ohmmeter. What does the voltage do on that pin? It looks like it is active low, which of course means you want the IRLP board set for active low. If you need to help things along, you may want to put about a 10K resistor on pin 8 going to 5V or 12V.

If you still need more help with it, give some more information. It shouldn't be that hard to get working.

Mick - W7CAT
Node 3464

----- Original Message -----
From: "Butch Bussen butchb@... [irlp]"
To: "'Roger Day' r.day2012@... [irlp]"
Sent: Friday, May 04, 2018 05:22:44 PM
Subject: [irlp] help with the COS on a Motorola M120 and a PiRLP Node

All of the nodes I have built use older systems and the version three
board. I don't think Mike is on this list, so I'm forwarding his note.

Do you have any experience with the COS on a Motorola M120 and a PiRLP
Node? It
looks like I need to construct a 4.7K resister with a 2222 transistor to
make the
COS work correctly. The stock function on the radio for the COS to
pin is
3.5 M ohm with no receive signal and 0 ohms with receive signal present.
In reading
the PiRLP manual, it has a jumper for COS low, which I would think would
great for
this, but it doesnt. If I move that jumper to High, the radio receives
for a split
second, then the PiRLP node keys the radio.
Its been a long time and too many surgeries since I messed with the old
Mike KFJ
Thanks for any help. You can reply to me to

Node 3148
Wallace, ks.
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