160m Vertical / 18m fg Spiderpole
[ Model 160-18-4WTH ]
CAUTION: VERTICALS USING TOP-HAT WIRES
CAN HAVE LETHAL HIGH VOLTAGE NEAR THE ENDS OF THE WIRES.
KEEP OUT OF REACH OF HUMANS AND ANIMALS !!!
* * * THE ANTENNA ON THIS PAGE HAS LONG TOP-HAT WIRES * * *
SPECIAL ATTENTION IS NEEDED HERE !!!
Although this antenna is short for the 160m band, with its top-hat loading it is still very efficient.
Of course ultimately its performance will depend on the quality of the radial network below it.
SERIOUS CONCERN: HIGH VOLTAGE ON THE ENDS OF THE TOP-HAT WIRES.
Make sure the top-hat wires are at least 2.5m (9 ft.) above the ground.
As always, feeding through a Common Mode Choke is a good idea.
If you install a good ground radial network, your feedpoint impedance will drop.
In that case you will want to us a HAIRPIN MATCH to improve the match.
This is the same drawing as above, but with this document, you will be able to print it or blow it up larger.
JPG-Datei [145.9 KB]
CONSTRUCTION TIP: If you like, make the vertical wire about 2m longer and then wrap the extra wire into a wide-spaced coil near the bottom. This will easily eat up the extra 2m of wire. Then shorten the top-hat wires about 50cm each. Finally, tune the antenna to resonance by unwinding a bit of the coil and shortening the vertical wire from the bottom. This avoids having to run around adjusting 4 different top-hat wires!
RSGB Review of this Antenna:
The Radio Society of Great Britain built, tested, and reviewed this antenna.
Their results were published in the September issue of RadCom.
A PDF copy of this file is available as a download, below.
THIS DOCUMENT IS COPYRIGHT OF THE RADIO SOCIETY OF GREAT BRITAIN.
Reproduced here with their kind permission.
This document is copyright of the Radio Society of Great Britain, reproduced here with their kind permission.
RSGB REVIEW OF THE SPIDERBEAM 160-18-4WT[...]
PDF-Dokument [610.4 KB]
This is a 34 page (!) document with Step-by-Step instructions for building the Spiderbeam 160-18-4WTH on a Spiderbeam 18m long telescoping fiberglass Spidepole.
PDF-Dokument [1.5 MB]