Once again, I will be doing the writeup of the ARRL 160M Contest for QST and ARRL.org. I am interested in hearing your interesting, inspirational - or offbeat - stories, mainly for the expanded ARRL
Tom, Most tuners do not have sufficient capacitance or inductance range to provide an optimum match on 160M. You can get a match, but it's probably a much higher Q network that we'd like. As a resul
-- -- I also recomend Stay-Brite solder (4% silver) and the Stay Clean acid flux (hydrochloric acid -- use caution and wear old clothes!). Acid flux is fine for radials -- copper and dirt don't care
________________ Barry and all, Your post reminded me of several past accounts of similar behavior with horizontal loops and dipoles. My personal theory is that efficiency and ground reflection are
_________ RG-6 construction varies widely from one brand to another. Try to find one that has a solid copper center conductor, since copperweld designed for VHF/UHF may have copper thickness less th
Pete, If you are using each antenna on one radio at a time, then you are correct. Special attention would be needed for... 1. Sharing the same antenna on two or more radios for diversity reception,
_____ KD9SV's advice is worth following if you suspect any problems at all with common mode RF pickup. But if you have been careful to make a "clean" installation with isolated or decoupled feedline
Antennas are reciprocal, so an external signal source might provide the solution. A small battery-powered signal source could easily be raised by a baloon. Its antenna could be a short vertical that
from DM4iM: ...2. 2 wires , each a 1/4 wave, one left , the other one right to the tower , with the horizontal sections going in opposite directions. -- Martin, This arrangement can work well. There
I went through a modeling exercise like this a while back: * A Tee-top vertical of #12 wire, 70 ft. vertical and +/-44 ft. horizontal has a non-reactive feedpoint (resonant) in the 160M band. * Lengt
I'll add to Tom's recommendations. I have used multiple ceramic discs in parallel for many years. Amplifier makers have been doing this for quite a while, as well (although the factory originals fail
To clarify... 1. Increasing the radiation resistance DOES lower the ground loss, since that loss resistance is a smaller portion of the total feedpoint resistance. 2. A folded unipole transforms the
While this book has good coverage of array fundamentals, its emphasis is primarily the higher frequencies (VHF into microwaves). And it's quite theoretical, with lots of math, since it was likely wri
Dave, K9AY Loop users in desert areas have had more difficulty making them work well than most other users. Those that have done OK often use radials -- typically 4 radials somewhat longer than the a
Mike, Interaction starts to be noticeable when the coupled tower or antenna is roughly 2/3 the size needed for resonance, and increases rapidly as the size approaches resonance. For example, I have a
These look like Miller 4629-RC. (Mouser stock no. 542-4629-RC) I've used other values in the same Miller product line, and Fastron brand in the same style, with good results. Gary K9AY ______________
Bill... As N6RK noted, your antenna needs to be shorter than resonant (capacitive) to make this work. Perhaps the biggest benefit is that once you are set up, you can do fine-tuning at ground level i
Yes, there is an East Coast advantage in the 160M contests. That's the way it is ... the location of global population centers is hard to change. Greater emphasis on regional results is one way to de
K2AV As one of those QRP ops, I've wondered how much I'm hurting myself by not having any RX antennas yet. N4RP -- Every little improvement in RX capability (antennas, radio, gray matter) will help
The objective is to avoid overlapping radials, as would be the case in most arrays with 1/4-wave radials. Interactions between individual radials can create spots where there is current cancellation