Topband: parasitic element

David J. Sourdis - HK1A hk1kxa at
Tue Aug 3 07:56:54 PDT 2010

One important detail,  if I am not wrong:You need more than a quarter wave parasitic elements. Otherwise, you'll be doing a parasitic element for around 3,6 MHz.It must be half wavelength minus 4% - 5% lenght for a director element.
Or: You install a near quarter wave element with radials or just one radial in the direction you want to enhance your antenna system.Resonate it at a higher frequency (4 - 5 %), while having your existing vertical open to detune it so it does not affect the parasitic tuning.Then retune your vertical if needed, with the parasitic installed and closed (radial(s) and vertical or sloping element connected).



> Date: Mon, 2 Aug 2010 22:16:07 -0700
> From: tree at
> To: ljdoyle at
> CC: Topband at
> Subject: Re: Topband: parasitic element
> On Mon, Aug 02, 2010 at 12:11:17PM -0400, John wrote:
> > tq all the antenna guru's, been thinking of adding a parasitic element  to my existing 135 quarter wave vertical  to give me a little more gain to the NW my question would it work?the the quarter wave wire would be insulated from the top of the tower and sloping toward the NW and another insulator at the far sloping end and anchored to a tree...appreciate anyone's opinion..John K1GUN
> Well - yes - it can help.  You can probably get a bit of gain - but maybe 
> more importantly - get some front/back.  
> One limitation is that you will only get it over a pretty narrow frequency 
> range (30 kHz or so).
> Tree N6TR
> _______________________________________________
> UR RST IS ... ... ..9 QSB QSB - hw? BK

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