Updating an SWR meter

[N4RMT]

I have a radio shack swr / power meter that I've used for years. I saw some large panel meters on flea bay and was thinking about putting the guts of my current meter in a new enclosure with a large meter. I'm not sure, but I believe it's a 100uA movement. (Confirm if you know). This should be simple, right? The meter has always proven very accurate and serves its purpose well. I just thought it would be cool to have a large, lighted face, and nice, metal enclosure.

Randy

[WB5WSV]

Well, if you want to do that, I'd leave the RS meter intact, put a larger metal box around it and extend the RF connectors out via short cables and SO-239's and hook the new larger meter in parallel with the old one. You could add an internal switch to switch between meters and thus be able to calibrate the new meter using the old one. And that way you would not ruin the RS meter.

But sounds like a lot of work to me. Instead I'd just buy an older Heathkit and try to restore it, maybe add a light. At least then you would likely be able to get the manual for it.

However what is really great is the kind of meter I have as part of my MFJ-969. That double needle SWR/Power indication really spoils you, fast!

Good Luck!

Robert
WB5WSV

[KO6WB]

You can gut the Radio Shack meter. Just remove it from the plastic case. You should have a PCB with two SO-239 connector on it. The board has the wires going from it to the front panel controls. It shouldn't be very many. One wire comes from the FORWARD detector another wire comes from the REVERSE detector and you may have a common wire possibly two. You can remove the controls from the plastic case if you want to use them. Then you would install all the bits and pieces from the old RS SWR meter and put them into your new case.
The most important thing you what to know is where the 2:1 point is on your new meter. Indications above that point=bad, indications below that point=good.
There's not a lot of anything that could be even remotely considered as complex in a RS SWR meter. Peak hold adds some more circuitry and you could add that if you want. It's more than just a capacitor that some meters have in them.
If you were so inclined you could even get a dual needle meter and have the FORWARD and REVERSE readings at the same time. Some of the folks like that.
Hope this helps
73
Gary

[N4RMT]

Yep. That's whatbim going to do. I have an old power supply case that I'm going to use. I'm going to order a 4 inch 100uA meter, and use some panel mount micro switches in place of the radio shack ones. I'm going to make the scale in photoshop, black background, white/orange markings. Going to ad an led back light as well.