On Wed, 10 Dec 97 15:52:09 -0800 Rich Measures <measures@vc.net> writes:
c
>>
>>The actual ratings of RG58A/U is 650W at 10 MHz not 10M. At 50 MHz
>it is
>>250W. But that has nothing to do with the discussion.
>>You must have been taking dancing lessons from another.....
>>
>I did the math.
Congrats
>>
>>>As I recall, the center conductor of RG58/u is quite a bit smaller
>than
>>>#16 -- like maybe #19. If 1A will "seriously heat up #16 gauge Cu",
>why
>>>doesn't 2.3A seriously heat up #19 (or so) gauge copper?
>>>- At 25A/60Hz, #16 gauge Cu gets seriously warm in free air. Does
>it =
>make sense that
>>> 1A at 28MHz could do essentially the same thing?
>>
>>
>>Why dont you just try it and find out.
>> Replace all the plate wiring and
>>strap in your SB-220 and key down for several minutes.
>>
>I don't need to try Cold Fusion to know that it's a delusion.
That is a pure 100% cop -out Rich. Do the test before you whine about it
please.
>- 1A at 28Mhz in #16 gauge Cu,, generating serious heat? Give us a =
>break. And besides that, if Ls was cookin' Rs, it would leave =
>barbeque grill marks on Rs, which it does not.
I suspect that you really do not understand RF
>,,, ,,,
>... ...
>>>One SB-220 owner told me that he took the 220 to work and put a
>probe
>>>from a spectrum analyzer through the perforated cover of the output
>>>compartment. The signal was 50wpm CW dits. He said he could see
>the
>>>damped-wave ringing at c. 110MHz at the beginning and ending of each
>
>>>dit, and whenever the amp. was keyed or unkeyed with zero signal
>drive.
>>
>>And replacing the possibly overheated and overvalue 47 Ohm 2W carbon
>>cured it ??
>>There should have also been grid current flickering when it was zero
>>drive keyed if the parasitic was that pronounced as to always be
>there.
>
>>It would not suprise me that a slight change in the L spacing on the
>>resistor would have altered the analyzer picture. Did your owner take
>his
>>tests thru to a cure or conclusion?
>>
>No. Damped ringing is not regenerative. Damped ringing will always
>=
>be there whenever the anode current changes, no matter how low the =
>VHF-Rp of the suppressor happens to be.
Damped Ringing....is this a new phrase for you....haven't heard that one
before except maybe in a pre 1940 QST.
>
>>Too bad; but that is still just a minor parasite....
>
>=80 no parasite, just damped ringing of an L-C resonant circuit.
Like maybe ding a ling?
>
>>I asked about a Big
>>Bang analyzer picture. Or do you find those dancing shoes moving
>again?
>
>One would need a memory-type spectrum analyzer to lay in wait for the
>=
>Big Bang.
Anyone that expects to offer an opinion that they wish to claim as fact
should have the proof. IMO you have offered none.
I should expect that any responsible amp manufacturer would at least own
a Spectrum Analyzer. It is only the fringe area that dreams up theories
without proof.....such as TWA # 800.
> Most stock amplifiers never ever have a big bang.
In plain English....Bull Shit
>... ...
>>The Big Bang will generate tremendous amounts of RF, at that instant,
>of
>>unknown frequencies. Zeners and the like do not handle that very
>well.
>
>- The current path from the alleged anode/grid vanishing-gas arc is
>=
>not through the bias zener. However, with a parasitic oscillation, =
>the fault current path would be through the bias zener.
Hey danceman....Parasitic or RF Bang...same path amigo...comprende??
>>It
>>does not have to be in the direct path if the wiring is saturated
>with it
>>and in the SB-220 at least the Zener protrudes into the RF cavity.
>
>It might be interesting to measure the C between the chassis and the =
>zener diode stud that protrudes in the RF cavity.
So do it
>
>>> The voltage drop across this amount of R would be 2.4v peak --
>which
>>>equals 0.06w peak in a 100 ohm Rs.
>>
>>That assumes a DC path only. If the L in the suppressor is acting as
>a
>>RFC then the R takes all the gaff or in actuality the load is
>somewhat
>>shared assuming an imperfect RFC.
>
>This L is only 0.09uH. With a DC pulse?, hardly. With a 110MHz =
>regeneration, possibly.
Yep....at DC no way
At 110MHz possible
Glad that you may finally be understanding RF Rich. Now take the complete
plate circuit RF components in your next lesson. By that I mean from the
plate cap to the input of the HF tank circuit.
Kudos to the few that have commented and understand where I am leading
this.
73 Carl KM1H
>
>cheers
>Rich...
>
>R. L. Measures, 805-386-3734, AG6K
>
>
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