Sure, you might get them to tune up on 12m or 17m, but they are more or less dead on those bands. May 04, , What does this do to the radiation pattern of the vertical? Unless you have some specific indication that you need a choke, I wouldn't bother with it at all! Wed, 20 Jan It has been enough to bite me while in my tent and transmitting. I have never had that much luck with air choke.
A voltage balun almost certainly guarantees some feedline radiation or reception , because there are very few "perfectly balanced" loads or perfect voltage baluns. This article is an attempt to define in simple terms how to get the most performance from your system, both on receiving and transmitting. I declined to re-tune the system so I removed it. If you have excess ladder line, it can be zigzagged while suspended in air, but it can't be closer than a few conductor widths to metallic objects and cannot be coiled on itself or laid on the ground. Use as short a coaxial cable as in a multi-band dipole system. Systems Requiring Antenna Tuners Antenna systems requiring antenna tuners or matching networks often have very high voltages or currents on transmission lines and baluns, even at modest power. Operation is safe for balun and coaxial feedline over the entire band.
Stealthish vertical HF antenna - Hustler 6BTV? : amateurradio
They are a good compromise between impedance extremes and feedline losses. This can produce very high currents at the same place where voltages are very high, the worse of both conditions appearing at one point in the system. The ground ideally would be a modest system of radials. RFI problems, either with the amateur equipment or consumer devices Noise picked up by the feedline being conducted to the antenna Signals picked up by the feedline decreasing the directivity of the antenna system, especially front-to-back ratio. Commercial examples of this are Gap, MFJ, HyGain, and Cushcraft "no radial" verticals, as well as Force 12 vertical dipoles.
DX Engineering 4-BTV Assembly And Installation Instructions Manual: The Dxe-vfcc-h05-a Vertical Feedline Current Choke
Description: Most antenna tuners work best into moderate to high impedances, rather than low impedances. This system is generally good on 80, 40, 20, 15 and 12 meters. I would have saved myself two weeks of headaches if I had gone this route in the first place. The balun should be located near the tuner, keeping the coaxial cable between it and the tuner as short as possible.