f6aoj.ao-journal.com and then « tuning short vertical » , menu left side.
It could help you to match your antenna.
73 to all.
F6FYA / Jean-Paul
Envoyé de mon iPad
> Le 19 sept. 2018 à 20:41, Tim Shoppa <tshoppa@gmail.com> a écrit :
>
> Your suggestion of a hairpin is a high-pass. Herb's suggestion for a
> series-L shunt-C L-network is a low-pass. Sometimes you might prefer one
> over the other.
>
> Or choice might be entirely driven by parts on hand.
>
> I happen to have some big old variable capacitors so all my tuners use them.
>
> But a younger ham probably wouldn't and might rediscover the variometer or
> other solution.
>
> Tim N3QE
>
>> On Wed, Sep 19, 2018 at 1:46 PM Clive GM3POI <clive@gm3poi.com> wrote:
>>
>> What I don't understand is why would you use more components than needed.
>> Why a capacitor (possibly vacuum). What is wrong in using a hairpin which
>> also DC shorts the vertical to ground. A combination of hairpin size and
>> top loading will give you 1:1 at your favourite 1.825 or anywhere else.
>> Perhaps WX0B's article needs a reprint in the NCJ. It really is simple just
>> a few microhenries of inductance and you are done.
>> 73 Clive GM3POI
>>
>> -----Original Message-----
>> From: Topband [mailto:topband-bounces@contesting.com] On Behalf Of Don
>> Kirk
>> Sent: 19 September 2018 17:29
>> To: Herbert Schoenbohm
>> Cc: topband; ash.kf5eyy@gmail.com
>> Subject: Re: Topband: Toploaded vertical - SWR
>>
>>>
>>> Herb (KV4FZ) mentioned an L network, and that is what I always use. Very
>>> simple, and you just plug you're measured complex impedance values (at
>> the
>>> frequency you want to be resonant) into one of the many online L network
>>> calculators to determine the amount of inductance and capacitance
>> required
>>> for the L network. I normally just wind my own coil for the inductance,
>>> and use high voltage silver mica caps for the capacitor.
>>>
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