[Antennas] 468/Freq in Mhz

Mon Aug 24 04:18:16 EDT 2009

NO!
The ratio of conductor diameter to the element length is important: it
influences the bandwidth of the antenna. Also, for fat elements, the antenna
is shorter.
In the older antenna handbooks there were tables indication the percent
shortening required, relative to the length/diameter ratio.
Alex	4Z5KS
-----Original Message-----
From: antennas-bounces at mailman.qth.net
[mailto:antennas-bounces at mailman.qth.net] On Behalf Of Chris Boone
Sent: Sunday, August 23, 2009 9:14 PM
To: 'rbethman'; antennas at mailman.qth.net
Cc: 'Jerry'
Subject: Re: [Antennas] 468/Freq in Mhz
Incorrect......size (width) has nothing to do with performance!!!! (NO
joke!)....#14 wire will radiate as well as tubing...only the Q will be lower
and BANDWIDTH will be lower...but a wire antenna has a B/W of 10% of so of
freq..so the higher you go, the wide the bandwidth of the antenna (say a
normal 1/4wave gnd plane) BUT there is NO performance improvement....
Skin Effect is how RF travels on ANY conductor.....this tubing is no
different than wire..its just the solid wire vs tubing of the same size is
wasted material in the center..that MATTERS on DC or low freq AC like
60HZ..but RF is does not care about the inside of the conductor.
Chris
WB5ITT
PG-9-5322 FCC Commercial RadioTelephone (originally issued 1974)
-----Original Message-----
From: antennas-bounces at mailman.qth.net
[mailto:antennas-bounces at mailman.qth.net] On Behalf Of rbethman
Sent: Sunday, August 23, 2009 1:04 PM
To: antennas at mailman.qth.net
Cc: Jerry
Subject: Re: [Antennas] 468/Freq in Mhz
Jerry,
Generally, yes. In specific applications that are also frequency 
dependent, the higher the frequency the better the aluminum tubing will 
perform because of skin effect.
In the instance of 160 through 10mtrs, you will probably do okay with 
the #14. I always cut a bit longer to begin with and trim to where I 
want resonance by test.
Above 10mtrs, the tubing will out perform the #14.
Bob - N0DGN
Jerry wrote:
> Hi out there,
> Is the subject formula good for both #14 wire and 1 inch
> diameter aluminum tubing? If not, please elaborate.
> Thank you. Jerry N6VG
>
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