Fred, did you remember or remove jumper W5 when you installed your noise blanker? W5 is near Q22, the transistor with the heat sink on it. If you forgot, the noise blanker is permanently bypassed.
A great test is a cheap lamp dimmer: the kind that makes a wall of noise on 80 meters when it's used. It only requires an investment of a couple of bucks at the hardware store to pick one up, hook it to a lamp and turn it on. If your NB is working properly, it'll kill the noise beautifully. Sometimes it's necessary to turn on the preamp when using the NB. Otherwise the noise pulses may be loud enough to mask weak signals but not strong enough to make the NB spring into action, even when set to "low threshold". In those situations the NB sounds completely inoperative until I turn on the preamp and, presto, the noise disappears. That's on of the rare times I use the preamp on the lower frequencies. Another good noise source for testing should be an old-fashioned doorbell or buzzer. The point is that the NB works on repetitive noise pulses. It is not effective against random 'pops and sizzles' such as lightning QRN and normal band static. Ron AC7AC -----Original Message----- I didn't have good luck with Elecraft's K2 NOISE BLANKER. I know its advertised to do all sorts of noise reduction .... not my experience. I even bought a 2nd NB, it did'nt work any better. One day 3 cement trucks, and a large pickup truck sat outside of our home. NB did nothing to eliminate these electrical noises. I fact, I couldn't find any ham band noises - that the NB would remove. Maybe it was just some sort of K2 setup thing, that I hadn't done right - .............. Fred, FL _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
