Interfacing NOAA weather radio with SAME into ID O Matic Controller.

[WQMF945]

Hi all,
I was looking for some information on how to interface a NOAA weather radio into a repeater controller to transmit warnings and such automatically. I was going for a Reecom R-1630C weather radio which has a audio output jack, and a end of message detector so it stops receiving when the alert is finished broadcasting. I'm trying to create a active low COR circuit on this radio which when NOT receiving there is some positive voltage and when the receiver is receiving it swings to a ground potential. I want to interface this into a ID-O-Matic II controller which provides the PTT out and audio out to the transmitter. However the big design problem is that there is already one receiver being used which takes up the (1) cor input and (1) audio input. I need to combine both the receiver and the weather radio receiver into one COR and one audio input. Any thought's on this? Can it be done?

[gewecke]

This company manufactures a dual port controller which is very reasonable.
Contact them by phone and ask for brian, the owner. He can help.


Integrated Control Systems


73,
n9zas

[ramal121]

A two port controller would be ideal. But if you need to use what you have, lets walk through this.

As far as audio, you have only one input to the controller. You can try to parallel both receivers audio to the one input. They should be high impedance and line level. They should mix OK. If there is a volume level issue between the two you'll have to pad down the higher volume to even things out then maybe adjust the drive to the transmitter if need be. The down side is if a WX alert is going off and somebody keys up the repeater and talks, it will just be a mish-mash. You are also open to more hum or noise depending on ground loops, etc.

For the COR I see a problem with the WX receiver. It has an alarm output, but looks like you can select only eight seconds or five minutes for the output duration. Too short or way too long in my opinion. What I would do is set it for eight seconds and have it trip an external timer. The timer output would in turn pull the COR input to the controller to ground. Set the timer to about a minute should give enough time to relay the voice announcement without tripping the time out timer. I use a lot of these, they're cheap...
http://www.elkproducts.com/_webapp_2...y_Timer_Module

[WQMF945]

I see what you mean. I have several idea's of what you might be able to do with the COR but I probably need to buy the WX radio and take the guts out and see if I can find some type of signal in there that is active or inactive when it's receiving. I first thought I could take the audio signal and run it straight to the audio input, and try to find something inside the circuit board that could trip a digital logic circuit to swing a PNP transistor from high to low that times for a few minutes or so. As for the dual port controllers, they seem nice but I like the challenge of making something work from scratch. I just like the hobby part!

[Sifter]

Just curious if you ever successfully interfaced the reecom with your repeater. Looking to do the same.

[WQMF945]

I never got the chance to get around to it. I did conclude that I think the best bet was to use another transceiver and use the ID O Matic to key that receive to the repeater split.