G'day, 1. Both birdies in #1400 are at the LF band edge of 10M one is from the K2 MCU clock the other is from the KPA100 processor clock. The latter can be put where you wish depending upon your priorities, no birdie at the top end of 75M or no birdie at the bottom end of 10M, take your pick. See KPA100 receiver tests, last point.
2. No birdie at 28020 3. KNB2 on #1400 works very well in my environment. Pulse noises from electric fences vanish. Broadband pulse junk from a faulty sodium vapour street lamp that is S9 on 160M vanishes. Not quite so good with the same source on 30M. I've no complaints. With apologies I will copy the following post from October 2000: <quote> Thought I'd add my two (binary) bits worth to the NB discussion: I find that my NB is very effective on an annoying popping sound (mostly on 80M) that I suspect is caused by an electric fence in the area. NB1 reduces it considerably and NB2 removes it completely. I get similar results for certain types of static crashes: NB1 is somewhat effective and NB2 is very effective. However, neither seems to be too effective against electrical noise from drill motors, etc. Back in August a couple of folks posted notes that they had increased C12 on the NB board by a factor of 10 to 20 (thus increasing the blanking gate width to around 1-2 milliseconds) and got much better blanking of electrical noise. So I decided to give that a try. Increasing C12 to 0.1uF definitely resulted in better attenuation (with NB2 selected) of some types of electrical and atmospheric noise. However, it resulted in a rather raspy sounding CW signals. Backing off to 0.047uF worked just about as well on noise and did not produce any noticeable effects on signals. As a result, I have made the following mod to my NB board: 1. Changed C11 from 0.001uF to 0.0068uF (using the original C12 cap) to give an NB1 blanking pulse width of 65-70 us (instead of 10 us). 2. Changed C12 from 0.0068uF to 0.047uF to give an NB2 blanking pulse width of around 500 us (instead of 70 us). Seems to be a good overall compromise for the types of noise that I hear. Your results may vary. 72/73, Larry W1HUE/7 <unquote> Regards, Mike VP8NO _______________________________________________ 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
