SV: SV: [AMPS] Final..

[sm5ki]

No it has been a frustating quarrel because whatever good argument was given
against your info, you just for the principle never gave in.  No fun at all
Rich.

Rich I understand you should take another glance into your old ARRL SINGLE
SIDEBAND handbooks and learn a little more on the 3/2 law by Child and
Langmuir . One good article is W6SAIs "Intermodulation distorsion in Vacuum
Tubes".

You say: "The good news is now you probably know that grid-current in
grid-driven
config. produces distortion". My good news are: it is  true unless you swamp
your input with a low impedance load. Up to the point the grid starts to
draw grid current in an AB1 stage very little power is drawn from your
driver. But as soon as there is grid current your driver has to deliver
power, of course. If your drivers regulation is poor to this varying load,
you get flat topping unless you use a swamping resistor across the varying
grid load. According to Warren Bruene W0TTK, in  another article in this
ARRL SSB handbook, your swamping resistor should absorb 10 times the power
the grid consumes. He talks about some other ways to solve the problem but
personally I consider the ACOM solution to use a 50 ohm dummy load at the
input a better one. This old EIMAC idea from 1957 and another one from an
old application note on the 4CX600, is an excellent way to get good
linearity and stability. The 4CX600 used undecoupled cathode resistors to
develope negative feedback and better linearity. As a side effect ACOM got a
much simpler input circuitry as well.

So, Rich show your teeth and take another dive into the physics of the
electron flow of in vacuum tubes and return for a moment to the childhood of
Ham SSB in these old ARRL SSB handbooks.

Hej daa de Hans





----------
>Fr¬n: measures <measures@vcnet.com>
>Till: "sm5ki" <sm5ki@algonet.se>, "Lamb" <k7fm@teleport.com>, "Lars Harlin"
<harlins@swipnet.se>, "AMPS" <amps@contesting.com>
>ümne: Re: SV: [AMPS] Final..
>Datum: sñn 2 jan 2000 23.49
>

>>
>>Thanks Colin! I am really sorry that I started this crazy discussion on the
>>DAF. If I only had known........
>>
>The good news is now you probably know that grid-current in grid-driven
>config. produces distortion.
>Presumably, you are now aware of the 3/2 power law.
>In my opinion, this has been a useful discussion.
>
>cheers
>
>-  Rich..., 805.386.3734, www.vcnet.com/measures.
>
>

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