Author: Hans Hammarquist via TowerTalk <towertalk@contesting.com>
Date: Tue, 21 Jun 2016 13:39:05 -0400
I changed the topic as I think this is what we reall y at discussin. qualifications and education of who's talking/writing. It makes perfectly sense to me, if the tuner is not connected to ground or
It's like putting lipstick on the pig -- don't even bother. Instead, install a balanced resonant antenna. 73, Jim K9YC _______________________________________________ ________________________________
Author: "Roger (K8RI) on TT" <K8RI-on-TowerTalk@tm.net>
Date: Wed, 22 Jun 2016 00:31:58 -0400
Didn't you once say "there is no such thing as a balanced antenna"? 73 Roger (K8RI) It's like putting lipstick on the pig -- don't even bother. Instead, install a balanced resonant antenna. 73, Jim K
Yep, but I was speaking more in terms of perfection -- i.e., that in the real world, most practical antennas are unbalanced by their surroundings, even if we attempt to make them a balanced antenna a
the The degree of "natural balance" that one might expect in a center-fed antenna will also depend on the frequency. Jim's description is very true at low frequencies, where antennas are a typically
Yep, but I was speaking more in terms of perfection -- i.e., that in the real world, most practical antennas are unbalanced by their surroundings, even if we attempt to make them a balanced antenna a
Author: "Roger (K8RI) on TT" <K8RI-on-TowerTalk@tm.net>
Date: Wed, 22 Jun 2016 16:12:49 -0400
That's what I truly like about an AIM. It gives you all the important figures about your antenna and at the frequencies you operate. Z, R, SWR, Return loss, loss, impedance bumps, mismatches and thei
Yep, but I was speaking more in terms of perfection -- i.e., that in the real world, most practical antennas are unbalanced by their surroundings, even if we attempt to make them a balanced antenna a
That is exactly what I try to do - see my website: "Clamp-on RF Current Meter - *the* most useful tool for RF interference troubleshooting." http://www.ifwtech.co.uk/g3sek/clamp-on/clamp-on.htm A per
Author: Edward McCann via TowerTalk <towertalk@contesting.com>
Date: Thu, 23 Jun 2016 19:10:57 -0700
Sent from my iPhone _______________________________________________ _______________________________________________ TowerTalk mailing list TowerTalk@contesting.com http://lists.contesting.com/mailman
Author: Edward McCann via TowerTalk <towertalk@contesting.com>
Date: Thu, 23 Jun 2016 19:15:22 -0700
Sent from my iPhone _______________________________________________ _______________________________________________ TowerTalk mailing list TowerTalk@contesting.com http://lists.contesting.com/mailman
(Apologies, Ed, I was tied up yesterday with Radio Club Secretary work.) The answer to your question is "With great difficulty!" All the things that can be done relatively easily with coax feedlines
Positively depressing, Ian. If we can achieve reasonable, albeit not perfect line balance, does it really matter? Consider a wire dipole strung between two tall trees and fed with open wire line str
Ed McCann AG6CX Measurement of common-mode and differential-mode currents on open-wire line are also very difficult because they require a complicated arrangement of current transformers and baluns.
Although difficult to manage, one could place ammeters or shunted pilot lamps at equal distances from the feed-point on the dipole itself, and observe current. Some of the first experiments using th
Or they use multiport VNAs and get to the result by algebra. If you look at the measured test data for a minicircuits RF transformer, you'll see full 4 or 5 port data. http://www.minicircuits.com/MCL
Author: Edw McCann via TowerTalk <towertalk@contesting.com>
Date: Thu, 23 Jun 2016 06:27:36 -0700
Any suggestions how to apply this concept to ladder line/open feed? Ed McCann AG6CX Sent from my iPhone _______________________________________________ _______________________________________________
Or they use multiport VNAs and get to the result by algebra. If you look at the measured test data for a minicircuits RF transformer, you'll see full 4 or 5 port data. http://www.minicircuits.com/MCL
*prove* almost perfect "Does it matter?" is a separate question from the ones about measurement technique that follow later. One answer is based on treating CM current as a potential interference pro
Balanced lines are probably of limited use these days: 1) amateur radio 2) fixed broadcast HF stations with high power (feeding a multi bay dipole array with open wire line is a natural, and low loss