Antennaware
[Top] [All Lists]

Re: [Antennaware] center loading versus ground loading

To: aa4nn <aa4nn@earthlink.net>
Subject: Re: [Antennaware] center loading versus ground loading
From: DAVID CUTHBERT <telegrapher9@gmail.com>
Date: Sun, 31 Jan 2010 18:57:13 -0700
List-post: <antennaware@contesting.com">mailto:antennaware@contesting.com>
Or I should say Art we can write an article or we can all participate. I
wrote an article on a 38' 160 meter vertical some years back for AntenneX.
Since then I've written 25 or 30 articles for AntenneX. A magazine with a
wider circulation would be nice.

On Sun, Jan 31, 2010 at 6:55 PM, DAVID CUTHBERT <telegrapher9@gmail.com>wrote:

> Gary,
>
> The Battlecreek is a good antenna. However, It looks like a lot of work
> though to get the tubing lengths correct before and after the 40 meter trap
> as well as to tune the 160 meter wire.
>
> Here is two band vertical that is easier to tune up. It is for 80 and 160
> meters and it tuned from the base. Put up the antenna one time and tune at
> the base. No relays. Direct feed with coax.
>
> We can write an article on the antenna for QST, CQ, or AntenneX if you'd
> like. Here is the antenna:
>
> *160 meters:*
> A 67' mast. This can be the long vertical kit from DX Engineering (about
> $200).  On top is a top hat consisting of six 0.5" aluminum tubes 6' long.
> Right below the top hat is a 70 uH inductor. It is made of 2 inch PVC pipe
> with close wound #14 THHN wire (from the hardware store). To adjust it to
> resonance on 160 meters a 10 uH base coil is adjusted.
>
> The top hat mass can be reduced by using the DX Engineering top hat with
> the long spokes. The inductor will need to be sized for this. I can do this
> in EZNEC.
>
> *80 meters:*
> A 64' wire spaced 2' from the mast. It is base tuned with a loading coil.
> About 2 uH. The bottom of this coil connects to the bottom of the 160 meter
> tuning coil. The coax attaches there.
>
> Put up the vertical. Tune 160 meters. Tune 80 meters. Done.
>
>     Dave WX7G
>
>
>
>
> On Sun, Jan 31, 2010 at 1:23 PM, aa4nn <aa4nn@earthlink.net> wrote:
>
>> HI Gary,
>> All you need do is emulate the Battle Creek Special.
>> You can google to get specifics.  The BCS uses only
>> one wire to top load for 160m and only one wire to top
>> load for 80m.  Excellent antenna...no switches, no tuning,
>> just change bands and go.  If you are unable to find
>> specs, let me know.
>> 73 & all the best.
>> de Joe, aa4nn
>> Lake Wylie, SC
>>
>> ----- Original Message -----
>> From: "Gary K9GS" <garyk9gs@wi.rr.com>
>> To: <antennaware@contesting.com>
>>  Sent: Sunday, January 31, 2010 2:41 PM
>> Subject: Re: [Antennaware] center loading versus ground loading
>>
>>
>> I have been contemplating an antenna design to cover 40, 80, 160M.
>> Basically ~32 ft of aluminum tubing/mast, a trap, then more tubing/mast to
>> ~60 ft (possibly using a capacity hat to tune on 80M) and then a second
>> trap
>> above the capacity hat with a T-top loading wire to tune on 160M.  My goal
>> would be no switching/control lines at the antenna.  I work almost
>> exclusively CW so I don't need to cover the entire 80/160M band.
>>
>> Thoughts??
>>
>> 73,
>>
>> Gary K9GS
>> ++++++++++++++++++++++++++++++++++++++++++++++++
>> K9GS
>> Gary Schwartz           email: k9gs (at) arrl.net
>> Check out K9NS on the web: http://www.k9ns.com
>> Society of Midwest Contesters (SMC)     http://www.w9smc.com/
>> GMDXA http://www.GMDXA.org <http://www.gmdxa.org/>
>> ++++++++++++++++++++++++++++++++++++++++++++++++
>>
>> ----- Original Message -----
>> From: "Art Trampler" <atrampler@att.net>
>> To: <antennaware@contesting.com>
>> Sent: Friday, January 29, 2010 10:48 PM
>> Subject: [Antennaware] center loading versus ground loading
>>
>>
>> I live on a fairly small lot and use a Hy-Gain AV640 for 40 through 10 and
>> currently have no antenna for 80 or 160.
>>
>>
>>
>> My backyard is about 90 x 70 but has some ill-placed and ill-shaped trees
>> for either wire antennas or a tower.
>>
>>
>>
>> So I am thinking of another vertical, but this one ¼ wave with a radial
>> field.  I would like to get 80 and 160 out of it.  I don't mind having to
>> guy it, or even having to pour a concrete base for it.
>>
>>
>>
>> My first thought is to use aluminum irrigation pipe as others have, and
>> have
>> about 60 to 65 feet of it, an insulator and inductor and high voltage
>> relay,
>> and then perhaps 15 to 20 of much smaller aluminum tubing, with a sloping
>> capacity hat of four wires going partially down the four top guys.  I
>> don't
>> know if I could get away from the relay, and put up a trap instead but am
>> wary of using a true trap (coil & capacitor) rather than just a large,
>> high
>> Q coil.
>>
>>
>>
>> As you can see this idea is full of possibilities and mechanical
>> drawbacks,
>> so the question is, is there that much to gain from the center-loaded
>> design
>> with capacity hat, versus a switchable tuning network at the base of the
>> antenna?
>>
>>
>>
>> Your input is appreciated.  I am hoping to make this a summer project and
>> reward myself with 80 and 160 in the winter.
>>
>>
>>
>> 73,
>>
>> Art
>>
>>
>>
>> Art Trampler, KØRO
>>
>>
>>
>> _______________________________________________
>> Antennaware mailing list
>> Antennaware@contesting.com
>> http://lists.contesting.com/mailman/listinfo/antennaware
>>
>> _______________________________________________
>> Antennaware mailing list
>> Antennaware@contesting.com
>> http://lists.contesting.com/mailman/listinfo/antennaware
>>
>> _______________________________________________
>> Antennaware mailing list
>> Antennaware@contesting.com
>> http://lists.contesting.com/mailman/listinfo/antennaware
>>
>
>
_______________________________________________
Antennaware mailing list
Antennaware@contesting.com
http://lists.contesting.com/mailman/listinfo/antennaware

<Prev in Thread] Current Thread [Next in Thread>