Maandelijkse archieven: maart 2013

40m 1/2wave vertical (Endfed)

Today i setup my new vertical for 40m. It is a 18m glassfiber pole from Spiderbeam extended with an aluminium tube from 4m long. Now i have the right length for an 1/2 wave for 40m (or 1/4wave for 80m)

I build the match with a LC network using vacuĆ¼m capacitor 5-100pF (5Kv) and a roller inductor 22uH. It was very easy to find the impedance. I add some radials, this give me an even better SWR. No tuning required between 7.000-7.200. The 50m coax length to the TRX influence the SWR a little bit, but no worries. Just need a better way to isolate the antenne, because a little rain and my little wooden shelf will be soaked…

For photo’s from this excellent antenna click here