For testing rx antennas you can build a simple test oscillator. I used an
1843 khz quartz clock oscillator. It costs $4 from Digi-Key, part X103ND,
page 250 of their Jan-Mar 99 catalog #Q991. Pin 7 ground, Pin 14 is + 5V,
pin 8 is the output for a wire for antenna. I run the circuit from a 9V
battery, with a 5.1V zener diode to pin 14, fed from +9V with a small
resistor. The catalog says 15 ma, but mine pulls 3 ma, so I use a 620 ohm
resistor, with 4 ma thru the zener. If the chip did pull 15 ma, then a 220
ohm resistor would be better. The zener can be a 1N5231 or IN4733, page 225.
You can request a catalog from www.digikey.com I put the test oscillator out
in the field to test EWE f/b. On the air tests are better, but we dont hear
JA every day! I built my circuit on a protoboard using #22 telephone wire
connections. My "student" N0CKD, Dennis, built one on a board, and put it in
a RS box with an on/off switch. Both gadgets work well and have helped on
topband rx antenna testing. There are still some circuits that we can build!
73 Bob W7LR
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