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 <[email protected]> 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 <[email protected]> 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:[email protected]] On Behalf Of Don >> Kirk >> Sent: 19 September 2018 17:29 >> To: Herbert Schoenbohm >> Cc: topband; [email protected] >> 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. >>> >> _________________ >> Topband Reflector Archives - http://www.contesting.com/_topband >> >> >> --- >> This email has been checked for viruses by Avast antivirus software. >> https://www.avast.com/antivirus >> >> _________________ >> Topband Reflector Archives - http://www.contesting.com/_topband >> > _________________ > Topband Reflector Archives - http://www.contesting.com/_topband _________________ Topband Reflector Archives - http://www.contesting.com/_topband
