[TowerTalk] 2 el monobanders

[T A RUSSELL]

N4KG  comments  below.

On Tue, 19 Jan 1999 11:16:31 -0700 "Ed Jensen" <k5ed@dzn.com> writes:
>
>Hi,
>
>I too had a TH3, but based on models and Steve's talk at Dayton went 
>to a 2
>el, but in a somewhat different manner.  I considered the C3S but cost 
>drove me to a semi homebrew solution.
>
>I reasoned that the problem with trap beams was the narrow bandwidth 
>of the parasitic els (Steve's figures showed about similiar max gains 
>available from trapped beams but over a narrower BW), so I used 
>monoband reflectors (used Hygain's dimensions from their 
>monoband beams) with the TH3 driven el.

>I used a TH2 matching section.  I spaced all the reflectors .15 WL
>from the DE (appeared to be about max for a 2 el using MNjr and 
>YagiMax).
>
>Results for DX and contests are better than the TH3 so I guess gain 
>is as would be expected.  SWR readings (measured through 90 feet 
>of RG8 foam and MFJ259B) are:
>
>14.00 1.8
>14.12 1.1
>14.29 2.0
>
>21.00 1.9
>21.19 1.0
>21.42 2.0
>
>28.0 1.4
>28.3 1.0
>28.9 2.0
>
>Nice thing is low wgt (I calculate abt 25 lbs), no tuner required 
>for 99% of my operating, and cost was about $25 (I buy any 
>used Hygain beams I come across).
>
>73, Ed
>
>Ed Jensen, K5ED, El Paso, TX, k5ed@dzn.com
>

	Sounds like the old  TELREX   TB-2?  antenna,
	with a trapped driven element and separate
	reflectors for each band.  

	Great way to home brew a second antenna	
	for side mounting below a higher beam.  ANY
	trapped driven element should work, such as
	the driven element from any MOSLEY tribander
	(TA33, TA32, TA31) or CUSHCRAFT  A3, A4, or
	their D3 dipole.   

	Put one of these at 35 to 40 ft and you will be 
	amazed at how it performs, sometimes beating
	your BIGGER and HIGHER antennas!

	de  Tom  N4KG


	

___________________________________________________________________
You don't need to buy Internet access to use free Internet e-mail.
Get completely free e-mail from Juno at http://www.juno.com/getjuno.html
or call Juno at (800) 654-JUNO [654-5866]

--
FAQ on WWW:               http://www.contesting.com/towertalkfaq.html
Submissions:              towertalk@contesting.com
Administrative requests:  towertalk-REQUEST@contesting.com
Problems:                 owner-towertalk@contesting.com
Search:                   http://www.contesting.com/km9p/search.htm