Phil,
4CX15000 is a tetrode whose single tone power output is theorically 36 Kw,
as per Eimac data sheet., but the obtainable power by such kind of tubes is
generally much less when talking about continuous carrier level.
>>>The output power doesn't matter as to whether the maximum output is
>>>carrier level or PEP. 1Kw is one Kw, and when you are doing 1Kw CW, you
>>>are also doing 1Kw PEP.
Often, the real curves of the tubes differ consitently from those deductable
by the graphic of constant current ones on data sheets, and a single tone
power is a different story than a carrier level.
>>>Technobabble. Let's get on with the story.
Saying it in other words, in a conventional class C final stage AM
transmitter useing with a single 4CX15000 the carrier should be one fourth
of max peak power to reach the claimed 36 Kw on the AM peaks.
>>>And where in my original statement was a saying that we tuned the
>>>amplifier up for true, linear, Class AB AM amplification?
You are VERY good at reading things that aren't their. When the Popular
Communications article came out last month on Bigradios.com (September,
1999, front page article, "CB Superpower Badboys, or organized chaos)
"aired", I had to field the same arguments from people who knew not what
they where talking about.
You would fall into that category on this subject. You may know GREAT
design for RF, and you may be able to build a large amplifier, but you know
NOTHING about the "Controlled Destruction" that the average 11 meter US
operator subjects his equipment to.
In other modes like FM, a wattmeter wouldn't read ever 36Kw of carrier power
because that level is well over the tube capability and (reasonable) gain
already went away at much lower carrier output.
>>>Your saying that a 4CX15,000 wouldn't produce 36Kw of carrier power on an
>>>FM signal when being hit with 14 Kilovolts on the anode, and far
>>>exceeding the grid current rating grid driven?
I think you better go back to electronics 101 if that is the case.
Let's suppose reasonable a 10 dB gain to have 15 kW for each tube, the
required drive power would be 1.5 Kw and the claimed 3 x 8877 could largely
meet requirements for 30Kw (two tubes).
Never, (even overdriving a lot) is possible to get twice that output (60Kw)
in term of carrier power with that configuration and those tubes.
>>>BS. It is done all the time in the Ghostrider and Bluegill amplifiers.
Last but not least, a 10Kv tube operated @ 14Kv has yes a bigger gain and
output (30-40%) but a much bigger probability of internal flashes.
Statistically, in a parallel of 3 tubes the flash is nearly sure each time
the full driving power is applied.
>>>With the grid being biased as deep as it is, we have not run into that
>>>problem very often.
And, we don't use three tubes, we use two. The 3 tube amplifier is an 8877
box. Personally, I don't like the 8877, but that was the particular tube
that was used in this amp... I am partial to the 3CX1200 myself.
Another point, a tetrode operated in GG doesn't differ substantially from a
triode in term of efficiency
>>>And what is your point here?
and 3 x 8877 would be a total nonsense in a grid driven amplifier.
>>>You really think so?
All the story looks as the fishermans' story (the real fish is much smaller)
or as something developed by someone with electronic bases but following
conventional behaves
>>>I don't deal in the conventional... I deal in the real and experienced.
and the readings of data sheets rather than a mere report of real facts.
>>>Well, next time you are stateside, I would like to take you to a
>>>"keydown" event.
And that goes for anyone on this reflector.... Interested or not, it is
fun, and for the stuffed shirt types, it can be eye-opening.
Concerning the reported corona effects, they may happen at nearly any power
depending by used antennas and enviromental conditions.
>>>Yes, and the world is flat, right?
Mauri,
I suggest that you do some research in the Peter Dahl catalog for CB use,
and you will find the 3 phase transformers that we use, as well as other
parts. Peter himself was one of the first to wind the transformers for a
gentleman named Bobby in Chicago that specializes, and is currently the
biggest mobile station that I know of.
You can peruse the catalog and look at the figures of the transformers he /
we use....
Then, come back and tell us the same uneducated nonsense that you continue
to pass as fact.
Have a nice evening.
Toll Free
Houston, Texas.
73,
Mauri I4JMY
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