I've been in Amateur Radio since 1974, and still find new and interesting things to do. I like to build, restore, and operate on the air. This blog has been running for many years, so be sure to check out "Jump to Posts on Specific Topics" in the RH column to drill down and find lots of stuff. Visit www.WB4IUY.net for the lowdown at WB4IUY. Email me at wb4iuy@gmail.com if you have any questions.
This started as a barn find. Over the years, I've had a few of these, and found them to be pretty accurate when calibrated against a known good meter. It's also easy to add a 2000 watt range, but I didn't do it to this one. I decided to modify this one to be a passive peak reading meter, and here's the scoop...
Remote sensor make for easy installation in the shack...
It started as this dirty beast from storage in a barn...
Pin diodes and 1uF cap added...
220k resistor added in place of 20k...
Blue 500k pot installed in 10w position, 100k resistors placed in series with the 100w and 1000w cal pots.
This is the unmodified schematic...
...and this is the schematic with the component changes.
Basic peak reading mods for meters with movements of 1ma or less (200uA or less is better for response).
