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Old 28th September 2012, 10:11 PM   #931
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Well, what do you think the answer is? What are the P & K to ground impedances?
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Old 28th September 2012, 10:20 PM   #932
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It's not about who's right and wrong - it's about what's right and wrong.
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Old 29th September 2012, 02:05 AM   #933
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Quote:
Originally Posted by zigzagflux View Post
Good grief, get over it. How arrogantly annoying will you continue to be? "I'm right, I'm right, I'm right !!"
Not even a thousand posts yet. Dude, they are just getting warmed up...

Besides, I've already offered a Cathodyne of actual equal impedance.
Merely giving what they say they want is of no relevance in resolving
the actual contest of whose brain stem is better hung. And let me tell
you, I'm like a walking Einstein, God's gift to librarians.

Its these OTHER ego mongers can't stand to believe this universe
the same infinite size it always ever was, not expanding. Their
junk is whats shrinking: Cathodes, plates, common sense, our
entire local galaxy, others like it. Fighting over the wrong model
to simulate it, splitting hairs instead of 377ohms.

This conversation seems less relevant than beer right now.
I'm gonna go correct that error.

Last edited by kenpeter; 29th September 2012 at 02:14 AM.
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Old 29th September 2012, 04:59 PM   #934
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If it pleases some of you to think that this discussion is about egos, arrogance or whatever, I won’t stand in your way. I thought it was about Cathodynes! Silly me…

KenPeter analyzed the Cdyne, recognized that its output impedances were different, and like the accomplished audiophile he is, modified it so that its impedances were equal and it had gain to boot. He then tested it and showed that the modified circuit in no way solved the major problem facing the Cdyne, the LTP and other cap-coupled drivers: DC pumping due to grid current.

So what now? Are we to abandon the Cdyne and the others? If so, then this discussion should indeeed stop (On second thought, let’s not go to Camelot. It is a silly place!) But I suspect some will still want to use it. So shouldn’t we properly understand it?

I don’t think that anything SY or I or others post here crowds out any discussions anyone else wants to have. Post away if you have other things to discuss! For those of you who would rather not hear more on the topic, why not just tune us out? For the rest, why not keep reading?

I believe we left off when I pointed out that Burkhart Vogel’s floating source model of the Cdyne also gives the accurate prediction of equal and opposite voltages when the loads are identical. But if he had been foolish enough to analyze that model for predictions of P and K impedances, he would have arrived at not the 1/gm of SY’s model, but at something closer to R/2, where R = Rk = Rp. (In fact, later on in his Letter to the Editor in Linear Audio, he showed that the P and K impedances are different.) Since Vogel’s model contradicts SY’s on impedances, isn’t at least one of them wrong? Shouldn’t this matter be given a closer look?
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Last edited by CPaul; 29th September 2012 at 05:01 PM. Reason: add "at"
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Old 30th September 2012, 01:40 PM   #935
SY is offline SY  United States
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I know it's absolutely CRAZY to actually get out a soldering iron, signal generator, and scope, but why don't you try that and try varying the loads simultaneously to see what the effect is (using the voltage divider equations to determine source impedance)? I've done this already with resistors and capacitors to confirm that my model gives accurate predictions (and that Rp or Rk/2 doesn't), but that seems to be lost in the noise. Nothing like seeing it for yourself.
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Old 30th September 2012, 04:46 PM   #936
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It is odd that in nearly one thousand posts there has been little or no comment on the experimental results.

John
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Old 30th September 2012, 07:51 PM   #937
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I for one agree with his experimental results! It’s the design of the experiment and his interpretation of the results that are problems.
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Old 30th September 2012, 08:07 PM   #938
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Then SY, I guess you believe BV's model (to say nothing of his derivation of P and K to ground impedances) is wrong.

We've been over your experiment before. Put a switch between ground and the junction of your varying, matched P & K loads. Throw the switch to any position at any time during your testing. It has absolutely no effect, does it?

When the switch is open, what are you testing? The impedance between the P and K, obviously. And with the switch closed? Why the same thing – the switch has no effect - no current flows through it! And since no current flows through it, no current can be flowing through any ground-based impedances, and therefore, they cannot possibly be being tested.

You don't even come close to testing the P or K to ground impedances - you're just testing the P to K impedance, which is 2/gm.

I encourage everyone to try this at home with their simulators, on the bench, or with algebra.
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Old 30th September 2012, 08:22 PM   #939
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See Figure 3 in my article which gives excellent prediction of experimental results for equal loads connected to ground. Your objection is a feature, not a bug.
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Old 30th September 2012, 09:03 PM   #940
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And Ptolemaic theory gave a pretty good prediction of planetary orbits. You are deliberately ignoring the the point.

Let's try again.

You connect large caps to the P and K. Between their other sides, you connect a series of different, center tapped resistances. All of the voltages you measure confirm that the impedance between the P and K is about 2/gm. This, in fact, is the impedance you are measuring.

Now you repeat your tests, this time with the center taps grounded. There is no change in any of the voltages or currents in the circuit. I trust you won’t deny this.

You are therefore measuring the same thing both ways: the impedance between the P and K. Nothing more. Nothing less.
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