I haven't done "pedestrian mobile" like the "Packers" but I have used a vertical with single "counterpoise" with a total length of 1/2 wave like that "reference vertical" they show on the web page would be on 20 meters.
First, we ARE talking verticals now, and a vertical has about a 6 dB disadvantage over a horizontal, provided the horizontal is about 1/2 wave high! That's not likely to happen below 10 meters on a portable or pedestrian mobile setup, so it's a moot point here. That aside, what is interesting about a vertical with one horizontal counterpoise wire is that the counterpoise radiates as much as the antenna. Typical "ground-plane" arrangements provide a lot of cancellation of radiation from the "radials" since then are generally opposite each other and fed "in phase" (all connect to the same electrical point, not to out-of-phase currents like a dipole fed at the center). With only one counterpoise, there is no cancellation. That produces a lobe straight up for NVIS propagation from the counterpoise that is virtually as strong as the lower angle lobe. Also the antenna becomes fairly directional (in the direction of the counterpoise) which helps provide some gain to overcome the near-ground losses when hanging from a pedestrian <G>. That combination can be dynamite for what a H-F Pack operator wants - a great mix of radiation angles supporting ground wave and sky wave contacts. The only consideration seems to be that it will probably help to have the counterpoise sort of generally pointing in the direction of the other station for ground wave communications, although the "directivity" is going to be very broad. Also, with the counterpoise literally "on the ground" that high angle radiation will be greatly affected by the condition of the earth under it. Ron AC7AC -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Brian Mury Sent: Sunday, July 04, 2004 10:20 AM To: [email protected] Subject: Re: [Elecraft] Antenna? On Sun, 2004-07-04 at 06:47, Mike Morrow wrote: > It confirms the very dismal performance of *all* those "popular" HF > short loading-coil verticals in comparison to the most simple, basic, > inexpensive quarter-wave vertical. TANSTAAFL! It's no surprise that a full size quarter wave beats any loaded vertical, but I disagree that they all have dismal performance. The best 5 are less than a 1 dB difference (with the best being a mere 0.3 dB difference). The best 13 are under 6 dB, which is less than 1 S unit. Only 4 have a greater than 1 S unit difference. >... -- 73, Brian VE7NGR _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
