I can't stand it anymore. I have pretty much kept my keyboard quiet. I have
gone back and read all the archives including Will's and still kept quiet.
But I just can't stand it anymore, so here goes:
The following observations are just my opinions and as such are NOT open
for "debate". You can agree. You can disagree. I just ain't gonna let you
"debate" 'em.
1) Witchcraft and superstition ALWAYS win out over science and technology.
2) Debates thru email are pointless. I propose the all the list members
cough up plane fare for the major debate participants. We put them all in a
locked room, naked, armed with baseball bats. When only one is left
standing, we declare him the debate winner, cast his theories in concrete,
and get on with our HOBBY!
3) It is obvious, to me at least, that most of those individuals debating
network responses have never been in the same room with a real network
analyzer, let alone used one to make accurate, repeatable measurements.
4) I have noted only one individual allude to the difficulty of properly
characterizing a device/network which doesn't come from the factory with
SMA connectors on it. This stuff is an art form guys, it ain't at all like
plugging your voltmeter probes into a wall outlet to see if the power is
on! The really sad part is that some people who call themselves "engineers"
are going to disagree.
5) Given the above observations, I don't believe that any of the
"commercial interests" represented on this reflector have the resources to
even rent the equipment, software, and experienced personel required to
make a proper one-time measurement, let alone do it on a regular basis and
still show a profit. If my boss asked me to turn in a budget to do a
characterization of the pi-net in my amp, I would ask for more than $100k
of capitol equipment and software and at least $50k labor. This would get a
first order characterization, complete documentation and a final report
explaining it all. You guys think this might be outa the HOBBY class?
6) I don't want a "parasitic suppressor" in my amp, I want a parasitic
ELIMINATOR! Better yet, how about an amp that doesn't need either? Maybe an
"unconditionally stable" amp? Sure, and after that "engineer" designs that
one, I'll have him turn this lump of lead into gold for me to finance the
perpetual motion machine he will build next.
7) This one outa really start the pot to boiling! Any of you guys out there
that work on solid state amplifier design ever seriously consider using a
device which has a hfe of ten or more times what is required? Sounds to me
like a disaster looking for a place to materialize. Why then, are most
(all?) current amplifier designs using tubes with guaranteed gain out to
blue light? No friggin wonder they will take off on their own at the least
provacation.
8)As I see it, even though there is no such animal as an "unconditionally
stable" amplifier, it is possible, with care, to design one that is NOT
susceptible to unwanted VHF oscillations. I can and will do this for any of
you just as soon as you can procure the component parts I need that are
made from "unobtainium", a rare element which only academics and staff
scientists are normally allowed to use.
9) Another pot boiler. I know personally of one amp which defied all
conventional approaches to "parasitic suppression" that, with the
incorporation of one of Rich's kits, instantly and completely became
stable. Doesn't a proven concept deserve at the very least a resonable
consideration? Maybe not if you have a financial or ego interest in
discrediting it. Give it a rest guys, everybody comes off looking like a
dipstick bozo in this never-ending battle.
10) This is gonna be the corker. I expect the pot to completely boil over
on this one. In some text I read many years ago, (I wish I could find it
now on my wall full of books and quote it exactly) it was stated that the
purpose of the "suppressor" was to lower the frequency of the parasitic
resonance of the tank circuit to a point below the "self-neutralizing"
frequency of the tube. Which is just a way of saying that the predominate
feedback was altered in amplitude and phase to the point where oscillation
cannot be sustained. So.... if one were to alter the amplitude and phase of
the feedback at some other node in the circuit, the inductance in the anode
would not be needed at all. Or.... if one were to pay close attention to
ALL the components including the "invisible parasitic" components in the
feedback path, and especially the reactances internal to the tube, one
could select a nice HI-Q inductor for the anode and be done with it.(Until
a tube had to be changed out or the bozo using it did something he wasn't
spoda.) About the resistor: When one is tasked with cleaning up the mess
left by kids with degrees who were told they were "engineers" by their
college profs, one learns how to "band-aid" poorly done microwave designs
by de-Qing everything in sight including the enclosure the circuit is in.
My personal favorites are "Echo-sorb" and a neat witches-brew of silicon
rubber loaded with iron powder. So.... it's not R-sub-S, it's not R-sub-P,
it's B-sub-S! The resistance, be it a huge resistor, lossy inductor, or
both, is there simply because it is not economically feasible to undertake
the effort required to achieve a near perfect design. Even if the
near-perfect design was achieved, it ain't a bad idea to crank in a little
insurance to cover the perfect idiot that's gonna use it!
11) And maybe the last point. The BIG_BANG. I've had at least my share,
probably more. Never had a tube get damaged (that I could prove). Never had
a big bang caused by a parasitic oscillation (that I could prove). Never
say never; see point 1 above. I can almost get one of my 4CX1000's to arc
internal on demand(Rocky-Point I believe). Never used 3-500's either. Maybe
only 3-500's have that problem. I personally find Rich's theory a bit of a
stretch, but I absolutly refuse to discount it out of hand just because it
has not yet happened to me. (See point 1 above).
I apologize for spelling and grammer errors. It's my wife's birthday, had
to take her out to dinner, it's late, I'm tired, ain't gonna go back and
proof this spleen vent. I will not apologize to anyone offended by this
long-winded tirad. You all brought it on yourself's by not really reading
each others post's, by not responding properly to direct questions, and by
general chest pounding. Screw you, use the delete key like I do!
73 & hope you all have fun in this HOBBY,
Larry - W7IUV
w7iuv@axtek.com
www.axtek.com/w7iuv/
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