Hi Roger, 50 ohm to 50 ohm matching can be done with two components by
using them as a parallel tuned circuit.
I have had good results on 6m using a parallel tuned circuit and taping the
inductor for both the input and load connections to achieve step up, step
down, or no step transformations. Minimum Q is determined by tube input C
and strays, maximum Q can be set as desired by the L/C ratio of the circuit.
This is not a great solution for multiband amplifiers but sure works well
for singlebanders.
73,
Gerald K5GW
In a message dated 10/8/2010 11:43:44 A.M. Central Daylight Time,
n1rj@roadrunner.com writes:
Here is a good site for calculating impedance matching networks:
http://bwrc.eecs.berkeley.edu/research/rf/projects/60ghz/matching/impmatch.h
tml
In the old days when exciters had tubes and tuned outputs, most linear
amps had
input Qs of from 1 to 2 or thereabouts. With the advent of solid state
exciters
without tunes outputs, the requirement seems to be for a higher Q to
provide the
flywheel effect. Measures recommends a Q of 5based upon Eimac
recommendations:
http://www.somis.org/D-amplifiers4.html
An L network matching 50 Ohms to 60 Ohms (3x3-500Z) has a Q of .44! I
addition,
an L network will not match 50 Ohms to 50 Ohms. This requires a 3
element network.
73, Roger
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