[Antennas] 1/4 wave vert,

Thu Aug 21 23:44:28 EDT 2008

Hello Joe,
I'd feed that antenna like a folded monopole. Drop a wire from the
top inside the tower, bond the wire to the tower at the top. Drive a
short stake (or small 2 foot water pipe) at the bottom inside the
tower. If it is wide enough and you have no rocks, go for an eight
foot ground rod. But in New England we grow rocks every place a
ground rod wants to be.
Connect some heavy braid to the ground rod then tie and solder the
other end to a good long insulator (maybe 2 inches between ground rod
and insulator), then connect the dropped wire from the top of the
windmill tower to the other end of the insulator.
Feed with coax. See where it is resonant. Insert a variable
capacitor or tapped air-dux inductor (about 3 inches in diameter and
use the whole unit as you'll be able to use on 160 meters. You can
also use one of those remote antenna tuners available from DX
Engineering - either Swiss or German made. If you're running 200
watts or less MFJ and others make remote antenna tuner boxes that will
tune at the feedline. THAT is the way to tune - at the feed line.
73
DR
On Thu, Aug 21, 2008 at 11:28 PM, Joe <nss at mwt.net> wrote:
> Hi Chris and all,,
>> Ok heres a question then, for the "Tower" section of this project, How
> about the style of a old farm windmill tower,, Like 10 foot spacing on the
> legs at the base. I wonder how much this would shorten the antenna on 80,,
> Plus how would feed such a beast? would feeding (connecting) to just one
> leg work or it be like lopsided.
>> Now that really would make it ever weirder. How about the same on 10
> meters? the crazy thing is a HUGE percentage of a wavelength wide!
>> Joe WB9SBD
>> Chris Boone wrote:
>>> Just make sure you have a GOOD radial system underneath it...any vertical
>> on
>> 80 will not radiate worth a flip without the radials...and broadcast
>> stations use 120 1/4wl radials...
>> Any antenna, wider is broader bandwidth...a caged vertical wider made of
>> wires around the vertical support will have a wider bandwidth as they
>> emulate a WIDE pipe :)
>> Chris
>> WB5ITT
>> Society of Broadcast Engineers member
>>>>>> -----Original Message-----
>> From: antennas-bounces at mailman.qth.net
>> [mailto:antennas-bounces at mailman.qth.net] On Behalf Of Jim Miller
>> Sent: Thursday, August 21, 2008 11:53 AM
>> To: nss at mwt.net
>> Cc: antennas at mailman.qth.net
>> Subject: Re: [Antennas] 1/4 wave vert,
>>>> Joe;
>>>> Our 80 meter Hy-Tower customers remove the stubs for 10-40
>> and add aluminum to the "stinger" on top for a full size 1/4w vertical.
>> They remove the wire in the center, bond the aluminum to the tower at the
>> top,
>> and feed the base section. The 24' of tower adds to the bandwidth
>> with the aluminum. Centered at 3.650, they use them on the entire
>> band without any physical stub changes from CW to the DX window.
>>>> Regards,
>>>> Jim, K4SQR
>> www.comteksystems.com
>> Our 19th year of Hybrid Couplers
>> Comtek, the 4-Square Experts\
>>>>>>>>>> ______________________________________________________________
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