[Elecraft] Small QRP antenna

K9MA k9ma at sdellington.us
Thu Dec 29 11:09:54 EST 2016


I think Fred meant an end fed 1/2 wave, NOT 1/4 wave. 

73, 

Scott K9MA

----------

Scott Ellington

 --- via iPad

> On Dec 29, 2016, at 9:30 AM, Fred Moore <fred at fmeco.com> wrote:
> 
> With an end fed 1/4 wave you only need a counterpoise that is about .05
> wave length.  it can be the coax or another counterpoise.  Although a
> counterpoise has some effect on radiation pattern of a quarter wave
> radiator, it is minimal.   You won't see much improvement in performance
> by going above .05 wave length..  it's not worth the trouble to increase
> the counterpoise length..   Fred
> 
> 
>> On 12/29/16 9:01 AM, mjisted wrote:
>> Looking at your text message on the elecraft board. About a half wave
>> length ...here is a question for you. I'm going to put up a half
>> wavelength of wire for the 5 mhz band. ..hyendfed can I use a quarter
>> wave length of counter point as a radiator ground plane. .. 
>> The. ..G0MVP. 
>> 
>> mjisted at btinternet.com
>> 
>> 
>> Sent from Samsung Mobile
>> 
>> 
>> -------- Original message --------
>> From: Fred Moore
>> Date:29/12/2016 13:04 (GMT+00:00)
>> To: elecraft at mailman.qth.net
>> Subject: Re: [Elecraft] Small QRP antenna
>> 
>> Don,
>> 
>> Thank you very much, for pointing out a very common issue that gets
>> mixed up into discussions.  Your point is so valid the random wire
>> always seems to get mixed into the 1/2 wave discussion for some
>> reason..  and should never be mixed together.  you are absolutely
>> correct..   thanks again regards..  Fred
>> 
>> 
>>> On 12/29/16 12:33 AM, Don Wilhelm wrote:
>>> Scott,
>>> 
>>> If the radiator is not a half wave long, it is not a "half wave".
>>> Yes, a random length wire may work, but please do not call a random
>>> length a half wave - the length of a half wave is quite specific.
>>> Similarly, a quarter wavelength is a specific length at a particular
>>> frequency.
>>> 
>>> 73,
>>> Don W3FPR
>>> 
>>>> On 12/28/2016 11:20 PM, K9MA wrote:
>>>> The counterpoise for an end fed half wave (or multiple) really doesn't
>>>> have to be anywhere near a quarter wave long.
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>> 
>> -- 
>> Fred Moore
>> email: fred at fmeco.com
>>       fred at safes.com
>> phone:  321-217-8699
>> 
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> 
> -- 
> Fred Moore
> email: fred at fmeco.com
>       fred at safes.com
> phone:  321-217-8699
> 
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