One of the features in QST that I read every month is “75, 50, and 25 Years Ago in QST.” There really are some gems in old issues of QST, and now that all of these back issues are online, they are readily accessible—if you’re an ARRL member, anyway.
NOV 1939: More Thoughts on Effective Antennas by Arthur H. Lynch, W2DKJ. This is a real gem of an article. The first gem is how Lynch compares a beam antenna to a light bulb with a reflector. I’m going to use this analogy from now on when I’m teaching about beam antennas.
The second is his description of how to measure the SWR on the antenna feedline, which is an open-wire feedline. He writes:
Six-volt flashlight bulbs coupled to the line by a loop of wire will do the trick. The amount of wire in each of the loops will depend on the amount of power in the line. In our case, a couple of inches was all that was necessary, with 500 watts input to the transmitter. First, locate a point on the line where the bulb lights up brilliantly and clip one bulb there. Place a second bulb a quarter wavelength along the line from the first. This point is easy to locate by finding the spot where the bulb shows the least brilliancy.
Now it is only necessary to increase or decrease the distance between the points of the delta [match] where they join the radiator until the brilliancy of the two bulbs is equal.
NOV 1964: Flagpole Without a Flag by N. H. Davidson, K5JVF. K5JVF makes a nifty vertical antenna for 160, 80, and 40m from a push-up TV antenna mast. You should still be able to get these masts. What you won’t be able to get anymore is the glass “king-size pop bottle” he used in the base of the antenna.
NOV 1989: Some Power-Supply Design Hints by Doug DeMaw, W1FB. W1FB shows us how to prevent RF from getting into and affecting a regulated power supply.
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