This is a short preview of Bill Hays’ very visual demonstration of Standing Waves, how they affect radio signals, and what we do about it. The entire seminar runs about 100 minutes, and is available on DVD from ARVN: www.ARVideoNews.com.
Video Rating: 4 / 5
In which Erin describes how to use a 50 ohm slotted line crystal detector and standing wave ratio meter to obtain the wavelength and voltage standing wave ration on a coaxial transmission line.
chill
I wonder how much RF energy was used in this demo and at what frequency.
Very Interesting video
Thank you 73
Colorado Springs, CO
40 watts on two meters. It’s hard to see here, but the “transmission line” is two parallel copper pipes (from the camera angle, it looks like just one). That makes it a balanced line, about 200 ohms. Bill says that all the principles he demonstrates apply to (unbalanced) coax as well.
THIS IS COOL…. Every ham should see this….
In that case i must misunderstand something, as i was guessing a little under 300 MHz, based upon the 1m or so spacing of the peaks.
The peaks happen at the half-wave points, so about 1 meter for the two-meter band. The complete DVD explains it pretty well.
Oh, including valleys. And the nulls are the zero crossings. Duh. (For some reason i was thinking the nulls were the valleys. Now i’m wondering where the hell my head was at.) Thanks. ☺
@KN4AQ Damn that clears a lot up!