Monday, August 29, 2011

Deviation Meter

I hadn't built anything in a while. And a friend mentioned the desire to have something to check for proper deviation on various Echolink and repeater setups.

In a prior blog, Are you narrow or wide?, I covered more of the background.


There is a lot out there on this sort of thing.

http://www.repeater-builder.com/projects/poor-mans-dev-meter/devmeter.html


http://www.repeater-builder.com/rbtip/deviationmeter.html

https://archive.org/stream/73-magazine-1993-08/08_August_1993#page/n23/mode/2up

So I suggested we build this and hook it to a an old dedicated scanner. And after construction we calibrated it against a club IFR-1200 service monitor.

If you are not found of breadboarding, the above 73 article has an etched board available:

http://www.farcircuits.net/test1.htm

Here is a video that my friend made:

You'll be disappointed to know that Radio Shack doesn't carry the 15 vdc panel mount meter anymore.

1 comment:

Steve said...

Well two years late comment...

That was a fun project. My friend K5JB (SK) challenged me to a design-off contest. He won the pizza though, with an even simpler design. We both calibrated our meters at a local commercial radio shop using an IFR. My friend N0ELS (recent SK) used this meter for 20 years even though it was just a breadboard. The article deadline was too near, so I sent the meter to Wayne Green who had his staff take the internal pictures. All I had was the first picture on my table top. The meter lasted longer than that Alinco :-)

There was just a couple typo's in there (resistor wattage, missing decimal point on freq) but I never got to proof read it. Most are obvious though.
73, Steve k5okc