What remains in this endless discussion is, that someone opens those broken
tubes and inspects them to see what happened? Who has the will and the
knowledge?
de Hans
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>Från: measures <2@vc.net>
>Till: "Tom Rauch" <W8JI@contesting.com>, "AMPS" <amps@contesting.com>
>Ämne: Re: [AMPS] Re: Poor Science
>Datum: mån 6 mar 2000 14.55
>
>
>>
>>> You asked for an example ... I gave you one that repeated itself.
>>> I am curious as to why I had to replace two 3-500z"s. The way the
>>> amplifier made a huge grunt and tripped the breaker ... with the 3-500Z's
>>> shorting and pieces of either filament or grid being loose in the tube
>>> tells me something violent happened. And since it occurred while moving
>>> the top cover in relation to the tubes and tank circuit, leads me to
>>> believe it was an oscillation. What is your expert explanation please ?
>>
>>Don't know. There could be several causes.
>>
>>Isn't the Henry interlocked? Did you accidentally short the HV to
>>ground?
>
>? Zzzzzzz -- shorting the HV to gnd could not cause this. .
>>
>>......
>>> >>2.) What type of tubes.
>>>
>>> HELLO !!! Already stated.
>>
>>DUHHH!!! What manufacturer. Do you understand that better?
>>
>? Tube type means something rather different than Manufacturer, Mr.
>Rauch. As one of our ''recognized amplifier experts'', I should think
>that you would be aware of this.
>
>>> >>3.) Why don't the photons generated in normal operation cause the
>>> >>same problem?
>>>
>>> You asking me ?
>>
>>Yes. I generally like to know if a theory is even remotely
>>reasonable before believing it. The "photon theory" is rubbish,
>>unless photons in California are different than photons in the rest of
>>the Universe.
>>
>>> >>4.) Why don't photons in gas-filled tubes specifically designed to
>>> >>detect photons have even modest amounts of current?
>>>
>>> >>5.) Why do hundreds of other amplifiers without covers not fail?
>>>
>>> ??? Has nothing to do with what I stated.
>>
>>It has everything to do with what you stated, because you offered
>>your "story" in support of Measure's claim that a photon can cause
>>a tube to suddenly draw so much current it with cause the relay to
>>arc and put the PA in an operate position.
>>
>>If that was true, why are radiation detectors optimized for this
>>purpose filled with gas, and why do they have peak currents
>>millions of times less than the current in a power grid vacuum tube?
>>
>Because a nearly ionized gas makes a more sensitive radiation detector.
>With the typical geiger tube, one gets a hit every second or so. With
>transmitting tubes, one may have a big bang every 8 years or so.
>
>>If that made sense, why do many or all amplifiers with tube arc
>>when exposed to room light? Why can't we use 3-500Z's as
>>photocells?
>
>smoke
>>
>>> >>6.) Since the saturated current of a 3-500Z is about 10 amperes or so
>>> >>(that's all the filament can "give up", even if you hold the anode and
>>> >>grid at 3000 volts positive), how does the oscillation cause enough
>>> >>current to shatter the filament or grid?
>>>
>>> I would really like to know what shattered mine.
>>
>>Well one thing we do know, it can't be anode current through any
>>kind of emission.
>
>You talk about about recurrent peak emission. A one-shot event might be
>a whole nuther ballgame.
>>
>>Maybe you simply moved the PA, and the filaments were ready to
>>break.
>
>Grasping at straws. Playing for time. // As I understand it, the bits
>of metal were from the grid cage. The filament per se was intact,
>although it was bent laterally.
>>
>>> >>7.) If the tube could supply that much current, how does it get that
>>> >>current so fast through the high surge impedance of the path from the
>>> >>energy storage area (power supply) into the tube?
>>>
>>> Good question ... but in this case as I recall there is no current
>>> limiting in the B+ or B- of the HV supply.
>>
>>Use logic. These alleged "gremlins" are all VHF parasitics.
>>
>>The reactance of the anode choke and even the leads inside the
>>PA would severely limit the current.
>
>There is very little ESR in a Henry 2K-4. The anode supply is one of the
>stiffest known. There is no glitch R. The filter caps are paralleled
>oil filled type.
>
>>The only major current that
>>could flow, assuming Henry didn't design-in enough ESR to limit
>>surge would be at dc and through an arc that actually sustained
>>high levels of conduction for a long period.
>>
>The big bang suggests a short period.
>
>>I think someone has a parasitic fetish.
>>
>Mr. Rauch's attempt to introduce a sexual angle into this entangle is
>quite interesting.
>
>>> >>If you have no explanation other than blind faith, then I can accept
>>> >>that and respect it. I never argue religion.
>>>
>>> I have no explanation, only suspect.
>>
>>OK, then I can accept the fact you have no idea what caused the
>>problem. Only a guess.
>>
>Perhaps disassembly of the parasitic suppressors and measuring the
>R-supps might help to make a better guess?
>
>W7MOI, the Old Timer who told me to ''Always Measure R-supp'', and to not
>go by appearances, happened to own a 2K-4 that did the big-bang thing and
>grid-fil. shorted a tube.
>
>cheers, Tom
>
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>
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