The antenna I saw at dayton looks like ladder line loops for each
element with relays along each element to close the loops for each
band selected. This is done with a relay control box. Seems to be a
good idea but there is always compromise. Relay failures and parts
with each board, control box and power output limitations.
On 5/20/09, Arthur Trampler <[email protected]> wrote:
> duh me...
>
> --- On Wed, 5/20/09, Dubovsky, George <[email protected]> wrote:
>
> From: Dubovsky, George <[email protected]>
> Subject: RE: [TowerTalk] MACAntenna
> To: "Arthur Trampler" <[email protected]>, "Pete Smith"
> <[email protected]>, [email protected], "Brian Gieryk"
> <[email protected]>
> Date: Wednesday, May 20, 2009, 8:47 AM
>
> Probably a typo in your email, Art, but I presume you meant feet, not inches
> ;-)
>
> 73,
>
> geo - n4ua
>
> -----Original Message-----
> From: [email protected]
> [mailto:[email protected]] On Behalf Of Arthur Trampler
> Sent: Wednesday, May 20, 2009 9:43 AM
> To: Pete Smith; [email protected]; Brian Gieryk
> Subject: Re: [TowerTalk] MACAntenna
>
> That's easy Brian.
>
> If the boom to mast is at the center of the boom, then one has 10.25" on
> that side of the right triangle; 17.333 inches on the other side of the
> right
> triange; and 20.13" turning radius.
>
> Art
>
> --- On Wed, 5/20/09, Brian Gieryk <[email protected]> wrote:
>
> From: Brian Gieryk <[email protected]>
> Subject: Re: [TowerTalk] MACAntenna
> To: "Pete Smith" <[email protected]>,
> [email protected]
> Date: Wednesday, May 20, 2009, 8:11 AM
>
> Perhaps a typo on their site, or an oversight, but how cane one have a
> turning radius (20 ft, 1 in.) LESS than the boom length (20 ft, 6 in.)?
>
> Brian
> KE6IYC
>
> On May 20, 2009, at 4:41 AM, Pete Smith wrote:
>
>> This year at Dayton, there was a vendor (www.mactenna.net)
>> demonstrating something called the SB20-10 Simple Beam. The basic
>> principle was described in a QST article in September 2008, applied
>> to a wire dipole, and I remember at the time thinking "You've
> gotta
>> be kidding." Now, however, the inventor has incorporated the idea
> in
>> a 3-element yagi, and unless he has cooked the books, the EZNEC
>> models look pretty good. On all 5 bands between 20 and 10 meters,
>> the models show very similar pattern and gain numbers and excellent
>> SWR bandwidth, all without motors, moving parts (other than relay
>> contacts), and at a decently low price.
>>
>> The manufacturer's web site is very forthcoming with information,
>> which tends to inspire confidence. Still, I'd appreciate hearing
>> what the gurus among us think.
>>
>> 73, Pete N4ZR
>> New Articles Daily - the Contesting Compendium at
> http://wiki.contesting.com
>> The World Contest Station Database, updated daily at
> www.conteststations.com
>> The Reverse Beacon Network at http://reversebeacon.net
>>
>>
>> _______________________________________________
>>
>>
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