[Elecraft] A Good Antenna Length?

[WILLIS COOKE via Elecraft]

Willis 'Cookie' Cooke, TDXS DX Chairman
K5EWJ & Trustee N5BPS, USS Cavalla, USS Stewart


On , WILLIS COOKE <wrcooke at yahoo.com> wrote:
 


Off center fed dipoles, Windoms and end fed half waves are primarily low power if not QRP antennas where you can do poorly with any antenna.  They are prone to arcing, heating and RF where you don't want it.  You are better off with conventional low radiation resistance antennas if you plan to use 100 watts or higher.  The search for an antenna that will make QRP sound like a kilowatt is futile.  The only way to do that is to have excellent conditions and infinite patience which will make anything sort of work.
 
Willis 'Cookie' Cooke, TDXS DX Chairman
K5EWJ & Trustee N5BPS, USS Cavalla, USS Stewart


On Saturday, July 5, 2014 11:55 AM, Dave <dave at g0dja.co.uk> wrote:
 


I tried a 40M OCFD for a while. I gave up on it and went back to a centre 
fed dipole instead.

Even on 40M it didn't seem very good and I was plagued with RF getting into 
PCs and them shutting down or
 periferals stopping working.  Plus, despite 
the hype, it didn't really seem to work well on other bands.  The Antenna 
analyser was very dismissive, showing resonances outside of the Amateur 
bands and, on some that it was supposed to work on, no sign of any resonance 
at all.

Dave (G0DJA)

----- Original Message ----- 
From: "Jim Brown" <jim at audiosystemsgroup.com>
To: <elecraft at mailman.qth.net>
Sent: Saturday, July 05, 2014 2:24 PM
Subject: Re: [Elecraft] A Good Antenna Length?


> On 7/5/2014 2:05 AM, David Cutter wrote:
>> You might consider an off-centre-fed dipole with appropriate balun and 
>> choke.
>
> Not if you're going to run power. An off center fed antenna generates
 high 
> common mode voltage, which will fry even the best choke when running 
> power. I wouldn't consider such an antenna at greater than 100W.
>
> 73, Jim K9YC
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