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#1
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I should have been more precise in my estimating (I know ... doesn't
make sense). I actually have 59' to play with. Dohhht! Cecil, any chance you can take one more look-see for me with EZNEC? How well do you think it will radiate on all the bands? Bob, you make a good observation regarding proximity to theater and Turkish reaction. When I arrived, I filed with the Turkish Telekomuncations Office (their version of the FCC) and got a Turkish Call sign, TA2ZAD. I figured it was appropriate whether I was going to go on the air or not, especially given that I brought a couple of radios into the country. ;-) I have a separate post going regarding using my SGC-230 coupler ... I was thinking about loading up the hot water pipes as a counterpoise and dropping a 100' of wire out the window. I saw a few folks' replies so far ... and they got me thinking otherwise now. Thanks! Rich (Please don't reply via e-mail ... dead address) |
#2
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Rich wrote:
I should have been more precise in my estimating (I know ... doesn't make sense). I actually have 59' to play with. Dohhht! Cecil, any chance you can take one more look-see for me with EZNEC? How well do you think it will radiate on all the bands? Since an analysis of a 51 ft. G5RV-shorty would be interesting to the group, I will do that, hopefully today. -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
#3
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Rich wrote:
Cecil, any chance you can take one more look-see for me with EZNEC? How well do you think it will radiate on all the bands? Rich, the easiest way for me to present a G5RV shorty version is by listing the 50 ohm SWR at the ladder-line/coax junction. The antenna is a 51 ft. center-fed dipole at 40 feet. The series-section transmission line is Z0 = 400 ohms with a VF of 0.9. I use Z0 = 400 because "450" ohm ladder-line is usually closer to 400 ohms. Freq. 50 ohm SWR for n' Length of "450" ohm line 6' 9' 12' 15' 16' 19' 40' 7.2 31 16 5.8 *2.2* 2.7 8.3 100 10.125 16 23 29 33 34 34 *1.9* 14.2 70 53 32 13 8 *1.2* 55 18.14 51 18 *1.5* 13 23 57 19 21.3 22 *1.5* 19 61 74 98 61 24.95 *1.7* 30 76 94 88 48 6 28.4 26 30 17 3.3 *2.0* 12 31 The lowest SWRs are highlighted like *n.m*. It appears that a fixed length of about 17 ft. will be a good performer on the harmonically related bands, 40m, 20m, & 10m. Varying the series section length from 6' to 19' would allow covering all HF bands except 30m. A 51 ft. dipole is not a good length for 30m and requires 40' of "450" ohm line to resonate it close to 50 ohms. IMO, any 50 ohm coax SWR above about 10:1 is unacceptable for ordinary coax (depending on frequency). -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
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