I am always amazed how some have so much difficulty making dipole antennas.
With multi-band dipoles (or Fans as it is being called here), tuning of one dipole interacts with the tuning of other ones. It is not too bad with harmonically related bands as the non-resonant reactance isolates the others pretty well. I made a 4125 KHz/5167 KHz dual dipole (Fan) for work and the two are so close in frequency that serious interaction took place. The lower frequency dipole (4125 KHz, Marine HF chan-4A) tuned pretty easily but 5167 (AK Emergency Chan) was extremely narrow in bw (10 KHz). That made 5167 not usable in some kinds of wx. But I have had a 80/40/20m dipole (now it is 80/40m) up for years and they are not that hard to tune. You start with the lower freq dipoles slightly long and tune the highest freq. dipole first. Then the next, and so on. You should re-check tuning on the highest freq.after tuning the nest highest to see if it is affected and make adjustment. I said not hard, but it does take longer to get all resonant. Using one of the portable antenna analyzers it the ONLY way to go (much simpler and convenient). 73, Ed - KL7UW, WD2XSH/45 ====================================== BP40IQ 500 KHz - 10-GHz www.kl7uw.com EME: 144-1.4kw, 432-100w, 1296-testing*, 3400-winter? DUBUS Magazine USA Rep [email protected] ====================================== ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
