Re: Anyone used a spiral wound coil as an antenna?

Guy Atkins

I too used a spiral loop for a while, but it was a broadband design based on the Wellbrook ALA100 (mounted on an antenna rotor). I eventually went back to a single turn loop for the ALA100, as the nulls seemed better.

Photos and info on the spiral loop approach can be seen here:


Guy Atkins
Puyallup, WA


--- In ultralightdx@..., Russ Edmunds wrote:
> These were directional with the peak/null being the opposite of a multi-turn air-core loop. My 2', 18-turn air core loop peaks off the 'ends' or the coil, nulls at the broad side. The spiral loop peaks on the flat side, nulls on the narrow edge. The spiral loop has both less gain and less directionality ( which also means less sharp peaks and nulls ) than the larger loop. I no longer have a spiral because it didn't do the job for me.
> Russ Edmunds
> Blue Bell, PA ( 360' ASL )
> [15 mi NNW of Philadelphia]
> 40:08:45N; 75:16:04W, Grid FN20id
> wb2bjh@...
> FM: Yamaha T-80 & Onkyo T-450RDS w/ APS9B @15'
> AM: Modified Sony ICF 2010 barefoot

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