Mark,
I have to disagree with you. Below is the direct quote from the Mosley web site
FAQ page:
http://www.mosley-electronics.com/faq.htm
Besides my using a Mosley at home they were used at most of the Coast Guard
LORAN stations at Kure, Wake, Johnston, Yap, Marcus, Palau, etc, etc. where I
would operate from.
FEED SYSTEMS - THE SIMPLER, THE BETTER!
Despite popular belief, linear radiators, normally employed in 2 and 3
element
parasitic arrays, have a driving point impedance of close to 52 ohms
when open at
the center. To feed such a radiator it is only necessary to connect a 52
ohm line at
this point to achieve the best possible match of line to antenna.
However, because of certain design characteristics, some beam antennas
require
elaborate and, sometime, unstable matching devices such as Gamma or
T-Match
systems or variations of these systems. Such devices are usually
difficult to adjust
and to maintain in adjustment when used in multi-band beams.
MOSLEY TRAP MASTER beams, however, are so designed as to not require
any unwieldy matching arrangements. This beam is fed by connecting the
line
directly to the open center of the radiator. Thus, an excellent match is
achieved
over the entire width of each Ham band resulting in extremely low SWR
near
resonant frequencies of each band and the ability to range from one end
of the
band to the other without excessive SWR.
By eliminating such matching devices, MOSLEY TRAP MASTER beams provide
their users with stable and dependable operation without the necessity
of frequent
trips to the roof or up the tower to make readjustment.
As I stated previously my Mosley was designed to connect a split lead coax
directly to the driven element but I decided to use a 1:1 balun.
AA6DX wrote:
> The Mosely yagis often are(?)/were capacitive fed ... their "Classic"
> series. No hard wired connection to the driven element. That created an
> "unusual" situation, where the driven element is longer than the reflector!
> Defeating a Classic system by connecting the coaxial cable directly to the
> driven would be a no-no, as would any other means of feeding, without proper
> engineering. Note .. no all Mosely's are/were "Classic" .. I have had
> several that were, including my 2ØM monobander, w/46' boom ... worky
> worky... and, at one time, a Classic 36 .. Mark---- AA6DX
>
> Original Message -----
> From: "Alan C. Zack" <k7acz@cox.net>
> To: "Randy" <rlake@webryders.net>
> Cc: "J.Hector Garcia M" <Hector@telecom1.net>; <towertalk@contesting.com>;
> "Scott R." <w4pa@yahoo.com>
> Sent: Thursday, April 29, 2004 1:22 PM
> Subject: Re: [TowerTalk] Mystery Hy-Gain tribander
>
> > Scott said there was no matching devices on the yagi. You say the SYS-36
> has a
> > hairpin matching device. I have a Mosley TA-33 that sounds very much like
> what
> > Scott is describing. I'd suggest checking out:
> > http://www.mosley-electronics.com/amateur.htm
> > and seeing if what he has matches any of the Mosley yagis.
> >
> > Randy wrote:
> >
> > > My guess would be a Wilson SYS-33....try to find some pics on the net..
> > > I have a SYS36 - 1 trap on the driven ele.but I have a hairpin on the
> boom
> > > attached to the DE.
> > > Good luck
> > > Randy N1KWF
> > >
> > > ----- Original Message -----
> > > From: "Alan C. Zack" <k7acz@cox.net>
> > > To: "J.Hector Garcia M" <Hector@telecom1.net>
> > > Cc: <towertalk@contesting.com>; "Scott R." <w4pa@yahoo.com>
> > > Sent: Thursday, April 29, 2004 2:21 AM
> > > Subject: Re: [TowerTalk] Mystery Hy-Gain tribander
> > >
> > > > I agree with J. Hector. A Mosley usually has one trap per element
> leg,
> > > where Cushcraft and Hy-Gain have two. And Mosley has a direct
> connection to
> > > the driven element, no matching devices,
> > > > but I usually use a balun.
> > > > 73
> > > >
> > > > "J.Hector Garcia M" wrote:
--
__________________________________________________________________________
Alan Zack
Amateur Radio Station K7ACZ
Las Vegas, Nevada, USA
Quality Engineer, The Boeing Company, Retired
Aviation Chief Warrant Officer, U.S. Coast Guard, Retired
U.S. Coast Guard, Always Ready, Always There
Every hour, Every day, Around the Clock and Around the World
SEMPER PARATUS
http://www.gocoastguard.com/
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|