I built the noise blanker kit for my K2 s/no. 4905 (I think) a few weeks
back, and I am beginning to wonder if it is working. I can not tell any
difference between NB1, NB2, whether hi or lo threshold.
It is said that it works against the sort of pulse noise I get here from
power lines
The best way I have used to test the effectiveness of noise blanker is
try to use the radio in a house with a common incandescent lamp dimmer
nearby the antenna connection. Use a wire antenna placed near the lamp or
wiring of the dimmer circuit if necessary to increase the coupled noise.
The
Another good source of in-home switching hash is the ubiquitous external
low-voltage halogen lamp power supply. In my experience, some of them are
completely quiet, some of them are anything but. If you have one of the
latter, though, you probably already know that. :-)
Bill / W5WVO
[EMAIL
Stephen,
Turn the preamp on and scratch/tap the Q21 case with a metallic object
(screwdriver) while turning the NB on and off. If the NB is working,
you will hear the sharp impulse clicks substantially reduced.
Many types of power line noise are not handled by the KNB2, it is great
on
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