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> >end >Barry Kirkwood PhD ZL1DD >Signal Hill Homestay >66 Cory Road >Palm Beach >Waiheke Island 1240 >NEW ZEALAND >www.waiheke.co.nz/signal.htm >----- Original Message ----- >From: Barry Kirkwood <bjk@ihug.co.nz> >To: <force12talk@qth.net> >Sent: Wednesday, 07 March, 2001 5:16 PM >Subject: C-4SXL > > >> Well, she is complete, assembled from the tower and a slow learning curve. >> With the 40m hairpin spread vy wide swr at balun 1.4 at 7015. >> 20m lowest swr at 14.2. >> 15m lowest at 21.4 >> 10m lowest at 28.4 >> I had the 10m driver set at the lowest (longest setting). >> All measurements taken with Autek Analyser at the balun. >> Antenna center at 50ft, ant pointing at ground, ie boom in line with >tower. >> This unit about 4 yrs old, only just getting into operation. >> Any comments ?. >> I work mainly cw and would like it a bit lower on 15 and 10. As I recall, the hairpin on the driven element had to be spread quite far apart to achieve lowest SWR. you really should be able to do better than 1.4. How is the bandwidth between 2:1 SWR points? I would try for a center frequency closer to 7070 kHz, by moving the shorting bars out just an inch or two each. The C-3 part is specced with 100 ft of coax, which broadens the SWR bandwidth slightly. Your 15m curve seems to peak high, particularly, but I wouldn't worry unless the SWR is above 2:1 at the lower band edge. Oops, I just noticed something -- I don't think you can trust these measurements. The tower is too close. Can you get it up on the top-center bolt on the mount, and then pivot it to a horizontal position? Maybe keep a tether a little way out on the boom so you can tilt it back down to reach if needed? 73, Pete N4ZR Contesting is! The World Contest Station Database is waiting for your input at http://www.qsl.net/n4zr -------------------------------------------- Force12Talk mailing list provided as a service by Force 12 Antennas, Inc. Force 12 Web site: http://www.qth.com/force12 Submissions: send to Force12Talk@qth.com To unsubscribe: send a blank e-mail to Force12Talk-leave@qth.com Force12Talk Message Archive: http://www.qth.com/force12/list/force12talk For problems with the list, contact n4zr@qth.com |
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