[TowerTalk] Telrex TB5EM antenna manual

[Monty Taylor]

To all that responded to my question concerning the identity of my antenna
and a manual.  It IS a Telrex TB5EM.  Two of the members responded with
measurements; Diameter 2" boom w/2 1/2 OD sleeves, 18' boom length,  element
spacing and length were as stated by N4KG in the Original message to me.
What a relief!  I am awaiting copies of the manual from two different
sources.  I will scan them and send them to anyone else who might want that
information.
-----Original Message-----
From: owner-towertalk@contesting.com
[mailto:owner-towertalk@contesting.com]On Behalf Of n4kg@juno.com
Sent: Tuesday, April 24, 2001 5:57 AM
To: TOWERTALK@contesting.com; mtaylor@sandstream.com
Subject: Re: [TowerTalk] Telrex TB5EM antenna manual


Here are some measurements I made on the TB5EM
we had at W8UM (Univ of Mich) back in the 60's.

The TB5EM has a trapped director,
trapped DE, and separate monoband reflectors
for 10, 15, and 20, in that order, from the DE.

The boom will tell you where the elements need to go.
DE-Dir = 8' 3"
DE-R10 = 5'
DE-R15 = 6'9"
DE-R20 = 9' 6.5"

The elements were held together with long SS screws
so you shouldn't need to measure anything.

Element lengths were:
(I'm not sure where the 10 / 15M trapped lengths
were measured, but suspect the inside of the traps)

R20 = 35' 6"
R15 = 23' 5"
R10 = 17' 3"

DE20 = 26' 11.75"
DE15 = 19' 9"
DE10 = 15' 7.5"

D20 = 27' 4"
D15 = 18' 9.5"
D10 = 14' 2.25"

Toss the Telrex Balun and use a coaxial choke or
good modern balun.

One note, our TB5EM sucked on 10M, almost NO pattern.
I suspect it was tuned very high in the band.  You might
want to model it as a 10M monobander and adjust the
element lengths to suit your desired frequency range.

Our 10M DE trap seemed to be resonate on the high
side.  We tuned it by placing a "gimmic" across the
trap (two insulated wires, one attached at each end
of the trap and taped together to for a small capacitor).
No, I don't remember the lengths.  I believe we grid
dipped the trap which was constructed of wire wrapped
on a Micarta insulator and a fixed capacitor epoxied to
the insulator.

73 / GL,  Tom  N4KG


On Mon, 23 Apr 2001  "Monty Taylor" <mtaylor@sandstream.com> writes:
> I purchased a Telrex TB5EM (I think) that was from an estate.  It is
> dis-assembled and in a bundle with the Telrex Balun.  Not as
> substantial as
> a TB6EM (I used to have one), and has about a 17 foot boom and 5
> elements,
> thinner walls that the TB6EM.  I really need an assembly manual BAD!
>  If
> someone can help me I would really appreciate it.  I will pay for
> all costs,
> even better attach it to an email and let me know how much I owe you
> for the
> trouble.
>
> Best regards,
> Monty/WB5GLB since 1967
> montytaylor@texoma.net
> 972 542-5414 Home
> 972 538-3295 Office
> 'towertalk@contesting.com

________________________________________________________________
GET INTERNET ACCESS FROM JUNO!
Juno offers FREE or PREMIUM Internet access for less!
Join Juno today!  For your FREE software, visit:
http://dl.www.juno.com/get/tagj.

List Sponsor:  ChampionRadio.com - Trylon self-supporting towers,
safety equipment, rigging gear, LOOS tension guages & more!
http://www.championradio.com

-----
FAQ on WWW:               http://www.contesting.com/FAQ/towertalk
Submissions:              towertalk@contesting.com
Administrative requests:  towertalk-REQUEST@contesting.com
Problems:                 owner-towertalk@contesting.com



List Sponsor:  ChampionRadio.com - Trylon self-supporting towers,
safety equipment, rigging gear, LOOS tension guages & more!
http://www.championradio.com

-----
FAQ on WWW:               http://www.contesting.com/FAQ/towertalk
Submissions:              towertalk@contesting.com
Administrative requests:  towertalk-REQUEST@contesting.com
Problems:                 owner-towertalk@contesting.com