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RE: Stacking 40 and C3E... Thanks for the reply.. I guess my main reasoning for putting the tribander on top was because my rotor plate is about 9 feet down in the tower (commercial type tower with no adjustment of rotor plate at this point in time). The mast was 20 feet which left approx. 11' above the tower. I wanted to get 12 feet separation but couldn't. I figured if the 40 were on top and with the "droop" in the 40 meter elements this would effectively shorten the distance between the 2 antennas..In my mind the interaction would be a bigger factor than the extra 11 feet for the 40 mtr beam..The 40 has been at this height (85') for several years and has played very well. It is located at 9,000' above sea level and the land slopes at about a 12% grade to the north/northeast. Also, I have had problems with loose hardware/connections etc. with the 40 mtr beam and have had to take it down in the past..(1 element at a time). My gamble was that the Force 12 will be more reliable and will require less maintenance.. If the C3E at 95' goes south I have a log periodic (T-8) at 50' and a C3E at 50'. If the 40 goes south there is no back up. Due to the location in the trees and in the mountains of Colorado, a crane isn't always accessible for repair. This played somewhat into my thinking too. In September W0DC and W0BV and myself will give it a real workout with CQWW RTTY. This location is not actually my home qth, but a rental cabin that I rent to hams..soon to have a website going with info on the rental etc. Those were the factors that played into my reasoning..right or wrong.. HI. 73 Ken W0LSD At 09:00 AM 7/12/01 -0400, you wrote: >I found your report on your stacking of a C3E and 40m beam very interesting. I >have a C19XR at 80 feet with a modified (W6QHS) Cushcraft 40-2CD 12 feet above >it. both antennas play extremely well and the SWR on each is as advertised. >Prior to installation I did a lot of research and found 12 feet to be the >minimum stacking distance in order to avoid interaction. Many people >recommended that if a 12 foot separation wasn't practical to turn one antenna >90 degrees. > >I'm a little curious why you decided to stack the 40m beam under the C3E rather >then above it. It would seem to me that you would want to elevate your lowest >frequency beam as high as possible. > >If you want to take a look at my array check it out on my webpage at >http://www.tiac.net/users/lpeters/www/antennas.htm . > >Les Peters, N1SV > >Ken Eigsti wrote: > >> Hi, >> >> Thought I would follow up with results with C3E stacked above a Ele KLM 40 >> meter beam as several of you were interested.. >> >> If you remember, I first posted wondering if C3E initial SWR measurements >> on the SAW HORSE were to be worrisome..I had nominal SWR on 10 and 20 but >> high on 15. (5:1) >> 50% of the responses said just make sure dimensions are correct and put it >> up, and 50% said point vertical or get it up in the air. I didn't have the >> ability to get it up in the air (trees all around tower) so just went up >> with the rechecked measurements. (which were correct) >> >> Here are the results: >> >> Plan was to put C3E on top of a KLM 2 ele 40 mtr beam, with spacing to be >> 10 feet. At 95' on top of the 40 @ 85', again the 10 and 20 were 1.2 to 1.5 >> as advertised but the 15 meter portion was still high, 3:1 at CW end and >> lowest was 2.2:1 on 21.300. ALSO the signal reports from DX on the C3E at >> 95' were 2-3 S units less than a C3E that was at 50' fixed on EU on the >> same tower, consistantly. >> >> Solution: >> >> I rotated the 40 meter beam 90 degrees and the SWR on 15 dropped from 3:1 >> on CW to 1.5 and 2.2:1 to 1.3 on SSB. Also, the gain appeared to come back >> with equal or better signal reports with DX Vs. the C3E at 50 feet. I have >> noticed the propagation plays a huge role in the signal reports, but the >> SWR improved greatly, and a majority of the time the top C3E is >> stronger..especailly at opening and clsoing of bands, which is the "way it >> is suppose to be". >> >> Moral of the story: >> >> Even though 10 feet would seem to be enough spacing (KLM 40 mtr beam and >> C3E) by rotating the antennas 90 deg. appears to have made all the >> difference in the world, with both SWR on 15 and gain.. All this time 40 >> appeared to not be affected with either gain or SWR..this from signal >> reports and measured SWR. Rotating did not affect 10 or 20. >> >> If you have a similar antenna system, you might want to plan on rotating >> the antennas 90 deg to each other.. >> >> 73, >> Ken W0LSD >> >> -------------------------------------------- >> 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 > >Attachment Converted: "c:\eudora\attach\les.peters.vcf" > -------------------------------------------- Force12Talk mailing list provided as a service by Force 12 Antennas, Inc. 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