ARI Sanremo Home Page Home Page Nominativo di Sezione ARI Sanremo
Home Main Menu Sezione ARI-RE Award Liguria EME Diploma Sanremo Search Members Downloads Forums Guestbook Login

Toggle Content Trova nel sito

Toggle Content .:Translate Language
Please select to change language

Klicken Sie auf Sprache ändern

Sélectionner pour changer la langue

Haga clic para cambiar el idioma
Autori › Vertical antenna for HF using a magnetic base
Vertical antenna for HF using a magnetic base

Vertical antenna for HF using a magnetic base

Last year, during an Castle operation for DCI award, I had problem with my usual antenna: it worked than suddenly stop running etc. I have finished my activation with many difficulties. Went home I found the problem: a screw not well screwed.
This event pushed me to make a "spare" antenna to be used in case of breaking of the main antenna.
This antenna being a "spare" one, has to have the following characteristics:
short, light, efficient, working on different bands.
I have used a magnetic base, born for V/UHF, as support.
The antenna is about 2,5 m. long, the coil is placed high (at 2 m.) to get a better efficiency.
The antenna is made: one aluminium bar diameter 8 mm., long one meter threaded to screw into the base while on the opposite end is bored to accept a second aluminium bar 6 mm. diam., one meter long.
The coil is supported by a plastic retain that accept also the rod.
The coil: I have tried to get it as light as possible; the wire is enamel copper 0.7 mm., wrapped on a plastic tube diam. 33 mm.; it has 64 turns and it is long 48 mm.
The coil is located at two meters from the base; it can be joint to the mast and to the rod with crocodile pliers.
To work different bands I have changed the size of the rod to maintain the same coil, infact:
for 40 m. the rod has an effective size of 60 cm.;
for 12 m. and 17 m. it is 20 cm. long; for 10 m. I take out the coil and use a rod 52 cm. long put directly on the mast to get ¼ wave (2 m. + 0,52 m.); all rods have the diameter of 2 mm.
In 40 m. the antenna has a loss of 1 S-meter point in comparison with a vertical 10 m. high, radiation resistance is 4,70 Ohms.
I believe that the photos of details and mounted antenna let understand how to build it.
If you have any doubt please contact me.

73 de Gianni I1UWF

Antenna View Antenna

Italian version

(11088 reads) Printer Friendly Page

[ Return to I1UWF ]

Nominativo di Sezione
Sezione A.R.I. Sanremo - 18.02 codice ASC che per la Sezione è G08

La Sede si trova in corso Mazzini n° 1, a fianco del Campo Sportivo, in Sanremo. La Sezione è aperta tutti i martedì, non festivi, dalle ore 21 alle ore 23 circa.

Indirizzo Postale:


Scrivi al Segretario
Indirizzo di posta elettronica certificata

Webmaster IZ1OQB PINO

Contatto per il Webmaster
Regolamento del Sito | Note Legali/Disclaimer | Come trovarci

Best viewed 1024x768 +

Questo sito appartiene alla Sezione ARI di Sanremo (IM) e non rappresenta una testata giornalistica in quanto viene aggiornato senza alcuna periodicità.
Non può pertanto considerarsi prodotto editoriale ai sensi della legge n. 62 del 07.03.2001.
I loghi, i marchi e gli script usati in questo sito appartengono ai rispettivi proprietari e a CPG-Nuke Team.
Questo sito utilizza la versione 9.2.1 di Dragonfly CPG-Nuke.
Theme by i1yst
Tutti i testi, le foto e i disegni tecnici sono esclusiva proprietà di © 2002-2013
Vietata la riproduzione e la copia, anche parziale, senza la previa autorizzazione di

All content are protected by the copyright law and may not be copied without the express permission and the active reference to a source!
Web stats

Interactive software released under GNU GPL, Code Credits, Privacy Policy

placeholder Support   Dragonfly   XHTML valid!   CSS valid!   Level Double-A Conformance icon, W3C-WAI Web Content Accessibility Guidelines 1.0   RSS valid!   Robots valid!   PHP   PhpMyAdmin   MySql   Get Adobe Reader   Unicode   Add to Google placeholder