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Introducing the DIY "Propeller Cap" Antenna

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Rich
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Rich Posted: Thu, Feb 23 2012 12:18 AM

Inspired by equal measures of boredom, the desire to start a project that can be worked on for half an hour at a time, and the new wiki for antennas ("Aerial FAQ"), I have begun building a DIY "propeller cap" antenna.

First off, everyone knows what a propeller cap is, right?

 



Rich
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The illustration below is taken from the Aerial FAQ.  What I have in mind for the "propeller cap" is essentially this folded dipole mounted to a piece of wood which is in turn mounted to the top of my BM4000 tower.  Mounting will be such that the antenna can be rotated/twisted/moved to take advantage of some of the directional qualities of the dipole.

 



Rich
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My NAD 7175PE receiver has a 300 ohm FM antenna input which accepts bare wire.  I used this receiver to test a quick & dirty prototype of the "propeller cap."

I bought a 1" x 2" x 72" length of oak trim from Lowes and drilled holes 145 cm apart.  I then took some 16 gauge wire I had sitting around and completed the prototype by threading the wire through the holes and essentially duplicating the illustration above.

I first used the automatic tuning of the NAD with my current antenna and noted reception of 22 stations.  I then used the propeller cap and noted reception of 32 stations.

 



Rich
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The rotation/twisting of the propeller cap will be accomplished using a repurposed loudspeaker mount and a few pieces of hardware from Lowes.  With the results from the NAD, I decided to continue finishing this project and testing with the BM4000. 

I've stained the oak to match the BM4000 tower, and I've painted the hardware black.  I'll probably finish and mount the propeller cap to the tower this weekend.

 



chartz
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chartz replied on Thu, Feb 23 2012 4:31 PM

Hi,

I have built this aerial, which works great (it's in my attic). But it is very directional.

Jacques

Peter
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Peter replied on Thu, Feb 23 2012 4:51 PM

Who is the very pretty girl, and how did you make her wear the silly hat!! Big Smile

Peter

Rich
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Rich replied on Thu, Feb 23 2012 5:08 PM

chartz:

Hi,

I have built this aerial, which works great (it's in my attic). But it is very directional.

Mon dieu, mon lycée anglais me manque!


Rich
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Rich replied on Thu, Feb 23 2012 5:08 PM

Peter:

Who is the very pretty girl, and how did you make her wear the silly hat!! Big Smile

Alas, just a random picture taken from the internet.


chartz
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chartz replied on Fri, Feb 24 2012 4:35 PM

Rich:

Mon dieu, mon lycée anglais me manque!

Euh... Français tu veux dire !Stick out tongue

Jacques

Rich
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Rich replied on Fri, Feb 24 2012 6:29 PM

chartz:

Rich:

Mon dieu, mon lycée anglais me manque!

Euh... Français tu veux dire !Stick out tongue

Je suis bete!  Francais, francais!


chartz
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chartz replied on Fri, Feb 24 2012 6:39 PM

Cool

 

Jacques

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