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Portable multi-band HF vertical

VE1COR and KB1RSE put together what they call a Wave-Missile Antenna Project. It makes me think of my old 742 Swan mobile antenna. The base serves as a counterpoise and is three 6 foot legs to stabilize the antenna. The vertical part is a simple 20 meter quarter wave with a loading coil in the middle that can be used for lower frequency bands.

The Swan mobile has something like a 3 foot base, a coil box, and then a whip to top it off. The coil box uses traps for 75, 40, and 20 meter band matching with trim capacitors to help tune it. The VE1COR is a bit bigger antenna and uses a tapped coil on it like the Outbacker for band switching. Using a CB whip for the top section and playing around a bit with coil placement and overall length should get around VE1COR’s 15 meter band matching problem and allow usage on the top bands.

The September 2012 QST has an article about what they call an NVIS antenna. That looks to me like just a dipole mounted low to the ground as a convenience to figuring out how to get some height on it – been there, done that. NVIS is an acronym for Near Vertical Incident Skywave. It is a low frequency antenna designed to emit mostly straight up. The frequency needs to be below the current F2 ionospheric reflection measure. It is useful for emergency communications because it allows relatively reliable semi-local links of up to 300 to 500 miles. (see w0ipi on this).

K6SOJ made a portable NVIS type antenna by running a 33′ wire from his Land Cruiser roof strung out to some convenient post, rock, or whatever. This is like a mobile whip tuned for 40 meters using the vehicle as a counterpoise and laid sideways rather than straight up. This sort of portable antenna is about as simple as it gets. Add another 30 feet or so to tune it up on 75 meters to make it a dual bander with a simple jumper.

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