Just for the record: the ONLY amplifier configuration that inverts phase is
the common cathode!
Soooo, when using the GG setup, you actually place a shielding grid between
input and output, but you have to take GREAT CARE to keep stray coupling
around the tube as low as possible, otherwise you open yourself to the
possibility of getting struck with positive feedback and get yourself a
power oscillator!
Most VHF and up oscillators are based on a common base circuit with a
capacitor between collector and emitter!
Alex 4Z5KS
-----Original Message-----
From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com] On
Behalf Of Alek Petkovic
Sent: Tuesday, March 30, 2010 1:22 AM
To: Zeitler, Lane LT, FST-1; Jim Thomson; amps@contesting.com
Subject: Re: [Amps] 'Radio Transmitters" by Stoke
Do a search on a book locator site for ISBN 0442080093
73, Alek
VK6APK
At 11:35 PM 28/03/2010, Zeitler, Lane LT, FST-1 wrote:
>Jim,
>Was this a book made in the 60's? I have never heard of this. I have a
>half dozen or so of SAI's handbooks and another half dozed by ARRL over
>about 4 decades. This book by Stokes is new to me.
>
>Lane
>Ku7i
>
>-----Original Message-----
>From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com]
>On Behalf Of Jim Thomson
>Sent: Sunday, March 28, 2010 5:05 AM
>To: amps@contesting.com
>Subject: [Amps] (no subject)
>
>Date: Sat, 27 Mar 2010 19:49:30 -0700
>From: "Bill, W6WRT" <dezrat1242@yahoo.com>
>Subject: Re: [Amps] 'good engineering'
>:
>
>On Sat, 27 Mar 2010 21:35:13 -0400, "Gary Schafer"
><garyschafer@comcast.net> wrote:
>
> >Jim,
> >I think that Bill needs to do a lot of reading. Orr's book is an
>excellent
> >start.
> >
> >In his chapter on amplifiers he specifically spells out what happens
> >to
>the
> >cathode current of a GG amp when no tuned input circuit is employed.
> >He describes how the cathode current follows the coax cable out to
> >the
>exciter
> >and back. If Orr is not believable have a look at some of the Collins
> >material.
> >
> >As to RF passing thru the chassis, again turning to Orr will explain
> >it
>in
> >detail of how RF does not pass thru the chassis metal but thru holes
> >in
>the
> >chassis
>
>REPLY:
>
>So THAT is where all this voodoo comes from!
>
>I wonder what Orr would have thought of the disk experiment we just
>did. Twice.
>
>You are right though, I will have to GET ONE OF HIS BOOKS. Like I said,
>several people have quoted him saying a GG amp is a phase inverting
>amp. I don't doubt the quoters but I would like to read that myself.
>
>I'll be back. :-)
>
>73, Bill W6WRT
>
>## Bill, are u saying you don't have an ORR book ?????? I think you
>can still buy
>the latest edition that came out.... before he passed away. It's
>superb.
>Hardcover.. and it's blue. 23rd edition 1987. 5th printing was
>1992 I bought mine in 1994.
>ISBN # 0-672-22424-0
>
>## What other books don't you have ??? We are going to get the
>infamous VO Stokes book
>onto the files section of the ham_amps yahoo reflector, but it will be
>in 2 x PDF's. Now, if we could take the stokes book.. and do a spread
>sheet of his tubing coil data, you would
>have the ultimate, bar none, tubing coil winding info. Normal coil
>formulae won't work on tubing
>coils. [that was a hint to Ian] Stokes covers tubing from 1/32" up to
>2" It has cool stuff... like exact uh vs tubing diam... for a
>straight piece of tubing [ no coil].. which comes in handy for
>designing hair pins for hf yagi's.
>
>## and yes, the output of a GG amp is 180 deg out of phase with the
>input. The 2 x are in series.
>
>## The stokes book is called.... 'radio transmitter's.... RF power
>amplification' 190 pages
>## Orr's book is 400-600 pages.
>## between those 2 x books alone.. is a huge wealth of info. There is
>stuff in the stokes
>book, that you won't see any where else.
>
>later...... Jim VE7RF
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