Homebrew tuner
 

All,
I am planning on building a "T" antenna tuner. ---Series Cap--Shunt
Inductor--Series Cap--
I scrounged up an old 5KW RF deck (FREE!!!)
It has 2 large caps (1 is much larger and has 2 ganged section) and a 10
turn tapped inductor (air core).

My question is:
Would I use the larger cap at the antenna side of the inductor or the
receiver side?
Does it make a difference?
I plan on using an alligator clip on the inductor until I can establish some
useful positions, then I will install a multi-position switch.

Thanks for any assistance,

Pat Hoban - N2ZVT

I plan on using an alligator clip on the inductor until I can establish
some
useful positions, then I will install a multi-position switch.

============================

I have always found crocodile clips to be effective provided they are brass
and not magnetic steel.
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Reg, G4FGQ.

I am planning on building a "T" antenna tuner

I scrounged up an old 5KW RF deck (FREE!!!)
It has 2 large caps (1 is much larger and has 2 ganged section) and a 10
turn tapped inductor (air core).

Would I use the larger cap at the antenna side of the inductor or the
receiver side?

Hi Pat, With all the T type tuners I have played with, one cap is always set
to maximum. Which one depends on whether the complex impedance you are
attempting to match is inductive or capacitive. I would think the larger cap
would be preferred on the one set to maximum, since that cap needs to be a low
impedance to rf.
To make your tuner more versitle, use jumpers or switches or whatever to
exchange the positions of the two caps. That way you have the best cap in the
right position for the impedance you are attempting to match.
W9CF has a neat T tuner simulator on his web page. I found it to be very
educational on how these tuners work, and helpful determining the value of the
components I needed to match various loads.
73 Gary N4AST

To calculate L and C settings of T-match and L-match networks to tune
vertical or inverted-L antennas, download program ENDFEED from website
below.

To calculate L and C values and efficiency of C-L-C T-networks download
program T_MATCH
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Regards from Reg, G4FGQ
For Free Radio Design Software
go to http://www.g4fgq.com
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