[ARC5] Can yoiu say...
David Stinson
arc5 at ix.netcom.com
Tue Jun 13 14:49:44 EDT 2017
>... You have to read the book on modifying
>Command Sets to understand the reasons
>for modifying them. AND THEY WERE
>GREAT TVI GENERATORS! Bob Macklin
Respectfully:
Those ideas were/are repeated endlessly,
friend to friend and magazine to magazine.
And they are myths. Myths.
Examples of exactly what I've been saying.
The only "understandings" in the Surplus
Conversion Manuls were mis-understandings.
They addressed "problems" that were of their
own making and created "solutions" that produced
even more problems. The "copper shielding for TVI"
is one such thing. Utterly needless destruction and
trouble for something cured by a single capacitor
and few moment's reflection. But "common knowledge"
becomes "fact" and then it's almost immovable.
For instance: The only reason TVI was a problem
with Command Set transmitters is because they
were loaded and fed improperly to common "ham"
antennas- which defeated their excellent harmonic
isolation. I'm not just talking through my hat; I put
them on modern spectrum display equipment years ago
and investigated several feeding options, including the
typical ham "just stick the coax/twinlead on it and go."
When properly matched to a 50 Ohm coaxial line
and a 50-Ohm load through a simple series capacitor,
the rigs were as clean as any modern transceiver.
There were NO spurious products anywhere near VHF.
The equipment I used had a noise floor of, IIRC,
better than -95 dBm and with the rig fed directly to its
internal dummy load, nothing in the TV ranges. Zip.
And the 2nd, 3rd and 5th harmonics were well
within legal limits. When fed the "ham way" of
the 50s and 60s, all that "nice" was gone and
there was plenty of ugliness.
Thus the rep for TVI and pink tickets which became
"beer talk" at ham club meeting, then fodder for
magazine articles, then became legend and finally
matters of near-religious dogma; unshakeable.
If one abuses technology, bad things result.
It isn't the fault of the technology; the problem
is the lack of understanding and plain, old stubborn
"Joe and Jim said it's this way so by God it's this way."
There was/is nothing wrong with the design.
There was/is plenty wrong with the lack of
understanding and of effort to understand
the transmitters before operatiing them.
As far as doing what one wants with one's own
property: I can't argue that it's legal to do so,
but why would one want to "do what one wants"
in a way that not only results in a poor outcome,
but causes needless destruction to one's property?
I mean, you can sledge-hammer your new Chevy
if you want; it's "yours." But don't then complain
because you can't rid to the ham club meeting in it.
73 Dave S.
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