[Elecraft] Miniature self-supporting HF antennas

[k3ndm at comcast.net]

Wayne, 
>From time to time, my radio club collars me to do a program at one of our meetings. I usually lecture on antennas targeting the new ham. There are two points I try to leave the crowd with: 

1. There is no such thing as the perfect antenna. Each is a compromise of some sort. 
2. No ham has too many antennas. 

Efficiency, size, effectiveness, cost, and bandwidth are all inter-connected. I wish you great success in your quest. I'll be watching as I too would like to discover the perfect antenna. Having said this, have you tried a vertical dipole fed with open wire or ladder line? You gain by having a low angle antenna with low transmission line loss, and it requires only one support. 


73, 
Barry 
K3NDM 

----- Original Message -----

From: "Wayne Burdick" <n6kr at elecraft.com> 
To: "elecraft" <elecraft at mailman.qth.net> 
Cc: "KX3" <KX3 at yahoogroups.com> 
Sent: Sunday, July 19, 2015 12:45:47 PM 
Subject: [Elecraft] Miniature self-supporting HF antennas 

Hi all, 

Have you found the "perfect" above-the-treeline backpacking antenna for use with your KX3 or other small rig? I've used everything from a 10-meter coat hanger whip, to a yagi that breaks down into two dozen pieces, to a dipole held up at the center by a willing (and tall) campmate. The variety (and price range) of such antennas is staggering. 

I've had pretty amazing results using short, base-loaded antennas on the higher bands--especially when conditions were good. My personal best is JA from W6 on 15-meter SSB, running 3 watts to a Maldol 48" whip. These antennas collapse and break down into just two pieces, taking very little space in my lightweight go-bag. This leaves room for a couple of 25' wires, adapters, and weights for times when there are trees available. 

But the search for the ideal miniature HF antenna continues: something both very compact *and* highly efficient. Ideally it would break down to a length of 8" or less, do an excellent job on 20 meters and up, and earn a passing grade on 30 and/or 40 meters. 

One other key factor, at least with the KX3/KX1/K1 genre, is to take maximal advantage of the rig's internal ATU. A wide-range ATU (such as the KXAT3) can turn a narrow-banded antenna into one that covers a full band or even multiple bands, within limits. One general approach is to coarse-tune the antenna's own inductance, then let the ATU do cleanup. 

Is the best antenna for backpacking a very small magnetic loop? A cleverly designed, center-loaded telescoping whip? A length of #30 wire lofted by a small helium balloon? (Or, more intriguingly, some combination of these?) 

I'd be interested in hearing about your antenna theories and field experiences, backed up by entertaining fish stories, if they aren't embellished to an embarrassing degree. If your supporting documentation is too voluminous for the forum (attached photos, etc.), feel free to email me directly. 

If anything substantive or surprising emerges, I'll do a followup posting. 

73, 
Wayne 
N6KR 

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