[Elecraft] PAR/LNR EFHW antenna

[K9MA]

I would be cautious about using a transformer above 40 meters, as the 
stray capacitance may be too large.  I haven't tried it, though, so it 
might work with some transformers.

73,
Scott K9MA

On 1/8/2018 20:22, VE3GAM wrote:
> the End Fed Half Wave Antennas group on Facebook,
> started by N4LQ, Steve Ellington,
> promotes the use of a 49:1 transformer
>
> Steve does have a couple of videos on Youtube where
> he shows you him making one of these transformers
>
> check out how to build one,
> image is on Elgin Amateur Radio Society's website
> <https://elginradio.files.wordpress.com/2017/10/49-1-unun.jpg">
>
> List of vendors of these if you do not want to build your own
>
>
>  49:1 Transformer Vendors
>  -------------------------------------
>
>  myantennas
>  http://myantennas.com/wp/
>
>  hyendcompany
>  https://www.hyendcompany.nl/
>
>  balundesigns
>  http://www.balundesigns.com/
>
>  MFJ
>  MFJ-1982LP/MP/HP, MFJ-1984LP/MP/HP
>  http://www.mfjenterprises.com/
>
>  packtenna (QRP only)
>  http://packtenna.com/
>
>  communicationworld
>  https://www.communicationworld.nl/antennes_end_fed_zelfbouw
>
>
>  2017.10.12 Al VE3GAM
>
> al ve3gam
>
>
>
> --------------------------------------------------
> From: "K9MA" <k9ma at sdellington.us>
> Sent: Monday, January 08, 2018 8:39 PM
> To: <elecraft at mailman.qth.net>
> Subject: Re: [Elecraft] PAR/LNR EFHW antenna
>
>> On 1/8/2018 16:59, Rich Arland wrote:
>>> Failing that path, has anyone hooked an EFHW to the internal ATU 
>>> with good results? I would also include a cut to frequency ground 
>>> radial that I would lay out below the antenna. That would be the 
>>> easiest thing and simple to employ.
>>
>> That definitely will not work:  The impedance of the EFHW is much to 
>> high for any internal ATU to match.  The 64:1 balun may work, though 
>> I haven't tried one.  QRPKITS has a QRP tuner, but it works only on a 
>> single band. Most any of the external antenna tuners will work, 
>> though they may be lossy.
>>
>> The best solution, I think, is to build your own L-network tuner.  
>> One coil, a 3-position switch, and one variable capacitor.  You don't 
>> have to get a perfect match, just within the range of the internal 
>> ATU, like 3:1. Once you find the right coil tap positions, the 
>> internal ATU should be able to handle the small mismatch with 
>> different antenna installations, etc.
>>
>> It may seem like a lot of trouble, but if you can match the EFHW, 
>> it's just about the most effective simple wire antenna you can use.
>>
>> 73,
>>
>> Scott K9MA
>>
>> -- 
>> Scott  K9MA
>>
>> k9ma at sdellington.us
>>
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>

-- 
Scott  K9MA

k9ma at sdellington.us