But the Caveat to that is you have no control over the loaded Q in an L
network. It is a function of load impedances.
73 Hardy N7RT
----- Original Message -----
From: "Roger D Johnson" <n1rj@roadrunner.com>
To: "Amplifier Reflector" <amps@contesting.com>
Sent: Thursday, January 15, 2015 10:53 AM
Subject: Re: [Amps] Amps with high swr question
Impedance matching is only one of the functions a tuned input circuit on
the input of a GG
linear amplifier performs. The other is the "flywheel effect" that smooths
out impedance
variations that occur during the RF drive cycle. Most autotuners are L
networks and do not
provide the Q necessary for this function.
73, Roger
On 1/15/2015 6:46 AM, Paul Christensen wrote:
"If someone has an amp that has high input vswr, why not break the path
between the amp relay and the input to the tube and insert a 200 watt
auto tuner? Between the relay and tube ... not in the receive path.
On the surface, this sounds like a relatively inexpensive way to
retain an otherwise good performing amp. What did I miss ?"
Several homebrew amp builders have done just that. One that comes to
mind is
the 3CX1500D7 amp made by K8RA (SK). He installed an LDG auto tuner
after
the RF input relay. You can see the tuner board mounted inside the
bottom
corner of his amp. Scroll down to page 7.
http://www.ldgelectronics.com/assets/discontinued_manuals/AT-100AMP%20Manual.pdf
Paul, W9AC
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