Recent e-mails and Facebook postings from Jim (W8NSA) and Michael (AA1TJ) got me thinking about my old W7ZOI/W7PUA power meter. The 15 inches (38 centimeters) of snow that fell last night gave me the day off -- and time to play with this very useful and interesting piece of gear.
The last time I used it I remember thinking that a digital readout would be nice. But I didn't feel like going back into the world of Arduinos and LCD screens. So I came up with a real Kludge solution: I had cheap little DVM that I wasn't using, so I just velcroed it to the side of the power meter. That little connector above the BNC is the output for a DVM. I might work on calibration later today.
Wes has some very interesting info follow-up info on the meter on his site: http://w7zoi.net/qststuff.html I really like the part about how the meter is so sensitive that you can see the thermal noise in the input circuit and can actually measure the strength of signals from your antenna.
I think I might need a low pass filter at the input of the meter. There are strong FM broadcast transmitters in this area (some of you may have listened to them in the background of early episode of the SolderSmoke podcast!). I notice that just bringing my fingers close to the input causes the meter and the DVM readout to swing up. That's not good.
In response to popular demand, "SolderSmoke -- Global Adventures in Wireless Electronics" is now available as an e-book for Amazon's Kindle.
Here's the site:
For the print version:
For shipping from a printer in the U.S. (probably better for N. American buyers) Click here: SolderSmoke USA Version
For shipping from a printer in the UK, Spain, or the USA (probably better for UK and other European buyers)
Click here: SolderSmoke EU Version
The two versions are identical, except for a minor difference in the paper used. That's why the prices are a bit different.
Bill's OTHER Book (Warning: Not About Radio)
Click on the image to learn more
W4HBK's QRSS Grabber: The Amazing Pensacola Snapper (Live!)