[ARDF] TRO-2 ARDF transmitters...

[Jay Hennigan]

Kenneth E. Harker wrote:
> On Fri, Feb 24, 2006 at 11:58:14AM -0800, Marvin Johnston wrote:
>> Take a look at:
>>
>> http://www.west.net/~jay/turnstile.html
> 
> Jen and I have built eight of these antennas and they work fine.
> 
> Our variation of this design is to use:
> 
> 4 ea. 8-32 x 1" round-head machine screws (in place of 3/4" long)
> 4 ea. aluminum arrow shafts cut to length with Dremel tool (in place of 
>   1/8" diameter uncoated bronze welding rod and 8-32 1" long hex spacers)
> 
> We figured the arrow shafts would look cool and would be easier to deal with
> than figuring out how to (a) find the hex spacers and rods and (b) bond them 
> together.  We discovered, however, that:
> 
> * Not all aluminum arrows use aluminum threading for the arrow heads - some
>   have plastic inserts.

If the aluminum of the shaft itself is in good contact with the nut on
the pipe this shouldn't be an issue.  Maybe use KEPS nuts but turn them
around so that the secured lockwasher is on the outside.  Add a star
lockwasher to secure the KEPS nut to the pipe.

> * The threading starts quite a ways inside from the end of the arrow - this 
>   means that the machine screw sticking out of PVC needs to be longer.  With a 
>   1.25" PVC cap, the longest screw you can possibly work through is 1", and
>   that was just marginally long enough for the arrows to have enough threading
>   to catch.  If I were doing it over, I'd use a 1.5" PVC cap and 1.25" long
>   screws.

Is it possible to use a Dremel tool or similar to cut off the excess
arrow material so that the threaded portion is closer to the end?  This
would allow the original screw lengths to work.  How well secured to
the shaft is the threaded portion?  Especially with plastic I would
think this could work loose.

Also, where does one buy arrow shafts?  A sporting goods store?  What
is the approximate cost?

-- 
Jay Hennigan - CCIE #7880 - Network Administration - jay at west.net
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