I know of three ways to increase the bandwidth of an antenna: 1. Add resistance. This is usually not a good idea, but works for military and diplomatic sites where they can just crank up the power. 2. Lower the Q, usually with fatter conductors. Search for “cage dipole” for examples. Also used at VHF and UHF. Loading coils are high-Q, so reduce the bandwidth of an antenna. 3. Parallel elements resonant at close frequencies. These can be driven, like in a log periodic, or passive. From looking at pictures, the Gap Titan appears to use passive elements.
wunder K6WRU Walter Underwood CM87wj http://observer.wunderwood.org/ (my blog) > On Dec 9, 2015, at 6:00 PM, Charlie T, K3ICH <[email protected]> wrote: > > I forget the name of it, (MAX-something) but there was an "antenna" produced > back in the 70's that consisted of a sealed center box with a coax connector > on the bottom and two eyes to attach dipole wires. The ads claimed good > match from 80 thru 10 M. It was basically a 50 Ω non-inductive resistor > across the feed line which also connected to the two eyes. It was potted, so > you had to destroy it to see what was inside. If did in fact radiate a > little and of course provided a decent match to the coax. > > Another "slightly" more efficient antenna was produced by the venerable B & W > Company and sold as a wide band dipole. It's coax feed point had a 6:1 > balun which fed a fairly wide (12" ??) spaced 90 foot folded dipole which was > terminated with a 600 Ω *resistor in the center, physically right above the > center fed balun. We had one at Microlog and used it quite successfully on > the HAM bands as well as the Marine SITOR freqs, however, a random 100 foot > dipole fed directly with coax thru an MN-2700 generally worked better. > > My point here is that there is a wide range of antenna types & performance > and they all work to some degree. > > Hard to beat a simple resonant dipole though. > > I agree with Joe. Nothing wrong with traps either, especially since there's > no 'tuner' required. > > 73, Charlie k3ICH > > > > * (Might be wrong on the value....seems it should be 300 Ω. Then again, > maybe the balun was 12:1) > > > ______________________________________________________________ > 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 > Message delivered to [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 Message delivered to [email protected]
