[Antennas] pipe for an antenna

Sun, 21 Apr 2002 19:57:52 -0700

The antenna handbook states tha when scaling an antenna for a diferent 
frequency, the diameter has to be scaled in a correct manner.  The cage 
antenna is used to giver greater bandwidth but it is also a little shorter.

I have been trying to find out about Aluminum irrigation tubing, electrical 
service stack conduit, copper waste pipe and exhaust pipe for making a 
vertical.  But have not found anyone who knows the strengths etc of these 
materials.  Perferably, the mast mounted on a 10 ft (above ground) 4by4, 
elevated radials, the vertical element self supporting.  If have to used 
the supporting guys as capacitance loading. Could put some of the loading 
wire inside the tube also.  Now how to figure all that out.

Does anyone know the rule for how much under the ground a mast (poer pole) 
should be in relation to that above ground?

Chris opr VE7HCB

At 01:08 AM 2002-04-22 -0400, Ronald KA4INM Youvan wrote:
> > Don't forget to factor in the difference in diameter of the pipe.  Not much
> > effect at say 160 or 80M, but noticeable to the antenna length calc at 10M
> > and above....
>
> > I doubt you'd consider pipe for 40 or 80M use....
>
>   One of my local my HAM clubs [AReU] did an antenna shoot out on
>7.125 MHz a few years ago, the reference antenna was made of 3"
>diameter aluminum down spout material. Three sections were screwed
>with overlapping sheeting.
>A 2 liter pop bottle was the base insulator.
>   The normally 32 foot length (for wire) turned out to be only 30 feet
>tall, three full sections, by calculation and in practice.
>(4 & 8 & 16 radials, each produced a 3 dB improvement in far field
>signal strength, over the previous)
>
>   I think top rail will make a good antenna elements.
>
>       73 (= Best Regards) de: Ron [email protected]
>    100% LINUX, 100% of the time.   SENT Time and Date are UTC
>        Visit my HAM Web SITE at: http://www.qsl.net/ka4inm
>
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