Home

Events

Projects

Logsearch

Links

G4AXX

30m Vertical L



Back to Equipment



A vertical with a single elevated radial is simple, and provides a modest amount of directivity.

A description can be found in ON4UN's Low-Band DXing (4th Edition pg. 9-21).


Click on a thumbnail below to see a larger picture

The coax to wire connections.

The vertical section is simulated as 7.3m, but cut to 95% of that (6.935m), to compensate for the dielectric constant of the fishing pole.

The 6m fishing pole and mast. The vertical wire is spiral-wound on the fishing pole to fit 6.935m onto the 6m pole.

The top of this particular antenna is 15.25m (50ft) above ground.

The single radial slopes down to the south, and is tied off to the garden shed with kite string.



Simulations

The antenna was simulated using EZNEC by W7EL.

The supporting pole could be insulated, but at this frequency only a very small current flows in the supporting pole.

The 3D plot.

The 2D plot.

The simulated SWR.



The following measurements were made with a N2PK VNA using VNA4Win software.

The first SWR measurement showing resonance at 10.53MHz.

The SWR shifted into the band by adding 44cm to the radial.




unique visits since Nov 2005