Thread: Gamma tube?
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Old June 3rd 05, 02:58 AM
John Smith
 
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Dale:

Yes, someone injected a T-Match in here, but no real interest in a
T-Match...

Warmest regards,
John

"Dale Parfitt" wrote in message
news:ODOne.7695$vK5.2782@trnddc03...

"Dave Platt" wrote in message
...
In article tJLne.13595$Vm4.9195@trnddc01,
Dale Parfitt wrote:

How can a T match have show a bias- it is balanced. Virtually all
the
serious EME arrays use this matching technique and show the major
lobe

dead
off the front.


Are they feeding directly off of the coax, or do they use a halfwave
(or other) balun between the coax and the T?

Check out any of the antenna handbooks for a Tee match. The driven
element
is insulated from the boom and split in the middle. Each side of the
Tee
taps out on the D.E. at a point yielding a 200 Ohm balanced feed. A
4:1
coaxial balun is used to transform the 200 Ohms balanced down to 50
Ohms
unbalanced.

Dale W4OP