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[AMPS] Re: Parasitics

To: <amps@contesting.com>
Subject: [AMPS] Re: Parasitics
From: jono@webspun.com (Jon Ogden)
Date: Tue, 19 May 98 11:32:50 -0500
>You replied: 
>> Source impedance does not concern us???  Tom, I think you need to go back 
>> and re-read your initial RF transmission line theory textbooks.
>
>
>Hold on  there Jon. There is enough of this personal attack BS on this 
>reflector. My general policy is when I see such insulting dribble, I 
>delete the post at that point. I'll continue this one time, because 
>you do have a technical point. 
>
Ok...I wasn't really trying to impune you.  Just to make a point that I 
didn't feel your comment initially correct.  It wasn't meant to be an 
insult.

>> source vs. load impedance doesn't concern us then why don't we just run 
>> PAs and transmitters into any SWR?
>
>We present the correct impedance to the anode, and that impedance 
>matches the time-integrated impedance of the anode. The anode simply 
>gives the tank a "tug" at the correct time (the tube is a resistance 
>that varies with time).

OK, that makes sense. 
>
>Matching the tube's source impedance in an non-linear (through the 
>duration of a cycle, I don't mean non-linear so far as power drive 
>vs power output) less than 360 degree conduction angle system 
>requires the tank have a smoothing effect on that impedance, mush 
>like a mechanical pendulum.

Yes.
>

>The goal is NOT to transfer power (unless we are building a 
>frequency multiplier stage), but to de-Q the system or reduce gain. 

Agreed.

>> Although I must say that the explanation given by Ian White does make the 
>> most sense.  By applying series to parallel conversions and doing good 
>> old fashioned network analysis, we can actually make a 100 Ohm resistor 
>> look like a couple of K-Ohms at a given frequency.  So in a sense it does 
>> absorb the energy. 
>
>What "energy"? If the system is stable, there is no energy except 
>normal harmonic and IMD related products of non-linear 
>amplification of excitation.
>prevent the amp from taking off.

Yes, you are right.  There is no energy to absorb.  I think I correct 
myself on that later on.
> 
>> Now, I don't mean to start a war, but you and Rich Measures (AG6K) say 
>> about the same thing regarding the function of suppressors.  So where is 
>> your beef with him?  You can answer that one personally to me if you wish.
>
>Do you really think all this personal insults belong in a 
>technical forum? I don't.
>
I fail to see how this question is an insult, Tom.  It was a simple 
question.  I know you and Rich don't like each other and yes, the name 
calling is not a good thing.  I'll admit, I get into sometimes and it 
doesn't help my credibility a bit.

>I've said all along the nichrome suppressor can do the same thing 
>as any other system, if you don't care about HF losses. Where 
>people are being misled is in the "my way or no way" view, and 
>especially by claims everyone else in the world, from Dick 
>Erhorn to Buzz Miklos is not only dishonest but technically 
>incompetent.

I wasn't around for the debate and I don't know what names you called 
Rich or he you.  All I know is what I hear people say.  I will pass 
judgement on you based on what I see you say technically not on hearsay.  
If my conclusions back up other people, so be it.  But I appreciate your 
frank discussion.  Personally, I don't have a problem with you unless you 
start spouting junk science.

>Bad theory and abused physics hurts our ability to understand 
>problems, and harmful suggestions hurt our wallets. Name calling, 
>slander, and personal insults  do not belong in an educational 
>forum. That is my "beef".

But just calling a theory bad doesn't do the job.  One needs to 
scientifically refute it and answer all questions.  I see evasiveness by 
both sides in this thing and lots of red herrings as well.  Theories can 
be proved or disproved by scientific methods.  Just saying something is 
junk science without a logical, scientific defense is just as bad as 
someone professing a theory without any proof.

So, no one has really proven to me that Rich Measures' theories are 
completely wrong.  The hard questions I raise aren't answered.  And I 
question both you and he to answer scientifically in order to get some 
kind of truth.  Not opinion, but truth.  If you think something is 
harmful, why?  If you think a theory is wrong, then why and explain your 
theory scientifically as an alternative.

That's what I'd like to see.

73,

Jon
KE9NA



--------------------------------------------------------------------------
Jon Ogden

jono@webspun.com
www.qsl.net/ke9na

"A life lived in fear is a life half lived."


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