Forwarding this link (below) to a 20-minute video because NVIS, and because the presenter, Dr. Ben Witvliet, is probably the best researcher on NVIS that I know of. - Jef ---------- Forwarded message

Okay, I suppose you mean Sierra Hotel India Tango, but whatever... Congrats on the General. Now you can build some seriously big antennas. :-) - Jef

#antennas

10 tight winds around the boom, non-overlapping, should make a good choke for this band. - Jef

#antennas

Joshua - Very nice to see someone putting this kind of effort into antenna building (and experimenting.) You could probably make a neater, and somewhat more effective choke if you coiled the coax tigh

#antennas

Oh, and it's a good idea to form a choke at the feedpoint with several turns of coax tightly wrapped together around the boom, to reduce the inevitable common-mode current you'll get due to feeding a

#antennas

Greg - At work so gotta keep this brief. The hairpin, or beta match, has some advantages in this application—mainly that it is symmetrical so it doesn't distort the pattern as a gamma match would at t

#antennas

Here's a closeup of the hairpin match on the one I built:

#antennas

Joshua - Back in January 2015 we held an antenna-building party at my place and six of us built "tape measure" 3-element Yagis for 2 meters. Quick and easy to make, and the flexible elements fold up f

#antennas

Joshua - Nice work. Keep in mind that the length of the driven elements (plural) should each be a quarter wave at the geometric mean of the frequency range of interest. It's not the tip to tip length

#antennas

Doug - Nice work, and makes sense too! Thanks for sharing this. - Jef N5JEF

#antennas #elmer #howto

On Tue, Oct 20, 2020 at 6:05 AM Jef - N5JEF via groups.io <jef@...> wrote: Here's a picture of my 10-ft diameter loop for 40-60-80 meters, a work in progress. Here's the flanges

#antennas #elmer #howto

Here's a picture of my 10-ft diameter loop for 40-60-80 meters, a work in progress.

#antennas #elmer #howto

The small transmitting loop, often described misleadingly as the "magnetic loop" antenna, with a circumference under ⅓ wavelength (in some applications, under ⅒ wavelength) is a practical example of a

#antennas #elmer #howto

Joshua - The three foot firestick will perform as a receiving antenna almost exactly the same as any three foot length of wire. A three foot length of wire without a ground plan will be most sensitive

#antennas #elmer #howto

Joshua - What kind of CB antenna did you get? Probably a mobile? Full quarter-wave whip, or loaded? What do you want to receive? I'm guessing not CB? For receive-only, you can use almost any piece of

#antennas #elmer #howto

Carl - It's not going to be a very good antenna, but as Greg indicated, all wires can radiate, and all antennas "work" as we see from all the anecdotal "evidence" posted by hams. Fundamentally, there

Ken - I like your thinking on this, but wondering what happens if these blankets get wet? - Jef

"The wheels of government turn slowly", they say. Except, of course, when they turn too quickly… http://www.arrl.org/news/fcc-grants-arrl-rules-waiver-request-for-fire-emergencies-hurricanes FCC Grant

More evidence of the value of NVIS to emergency preparedness and disaster management. - Jef http://www.arrl.org/news/view/5-mhz-interoperability-channels-designated-for-wildfires-and-hurricane-sally-r

Alan - Thank you very much for sharing this. In many ways, "the system" is broken or needing improvement, and it's important that we consider the challenges facing us in the bigger (and bigger…) pictu