[SixClub] vertical antenna(directanswer)

[Steve Katz]

Actually, a 5 WL long wire for 50.125 MHz is 93.37 feet.  1WL is 18.673 ft
at the same frequency.

However, you won't achieve much useful gain doing this.  Here's why:

1.  Such a long wire has bidirectional gain along the axis of the wire, with
large nulls perpendicular to the wire.  A terminated long wire has
unidirectional gain along the wire axis, favoring the terminated end.  In
either case, any useful gain is found in a few very narrow lobes with large
dips between; if you can't rotate such an antenna, it's not very useful
because you never know what direction you want to work.

2.  A long wire that's any integer of 1/2 wavelength long, e.g., .5WL,
1.0WL, 1.5WL, 2.0WL etc, has such a high feedpoint impedance that it's very
difficult to match.  You can build an end-fed Zepp using a 1/4-wave balanced
line feed to help match it, but high-Z balanced line feeds have radiation
loss at 50 MHz and the feeder length becomes very critical.  Other networks
can be derived to accomplish a match, and any of them will be frequency
critical and not allow much band coverage; that might be okay if you only
want to work 50.1 to 50.3 MHz or something, but you'll never achieve a band
match.

3.  The skin (surface) resistance of the wire itself becomes a major factor
in long wire antennas, prohibiting too much resulting gain.  The old saw,
"If that worked well, everybody would be doing it" is pretty applicable.
Long wires and their attributes have been well known for about 85 years.

-WB2WIK/6






-----Original Message-----
From: Ben Ramler [mailto:ben_ramler2002 at yahoo.com]
Sent: Tuesday, June 20, 2006 12:36 PM
To: World Wide Six Meter Club
Subject: Re: [SixClub] vertical antenna(directanswer)


So according to this email then, Longwire dipoles can
work on 6 meters yes or no. someone answer this for me
please?

--- K2UBG at att.net wrote:

> Mike,
> 
>     The wire length for his 5 wavelength longwire
> computes to 98.425 feet. The Google calculator shows
> 6 meters equals 19.685 feet. Not sure why it was so
> hard to get an answer to your question on a list
> that is supposed to be devoted to helping
> others...give a man a fish/give me a break.
> --
> 73, 
> John/K2UBG
> 
> 
> -------------- Original message from KG4ROF at aol.com:
> -------------- 
> 
> 
> > 
> > 
> > WHAT LONG WIRE DID YOU USE? 
> > KG4ROF EM90 
> > 
> > 
> >
>
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