In a message dated 5/16/06 8:09:51 PM Central Daylight Time,
amps-request@contesting.com writes:
<< eff,
I'm glad the book work was dug up. Was the Harris manuals the originals that
were supposed to be missing, or copies that Harris had when it was originally
built? What I had heard was the manuals and maybe the schematics were missing
at the transmitter site. When the place changed hands, things gets moved and
lost. Heh, I would like to see it brought to life one more time. That was one
station that the Queen used to request songs from. The only problem they said
was it drowned out everything in Canada, LOL! If I recall, they did fire it up
for the year 2000 at midnight for a short while. What power they ran, I don't
know. That transmitter reminds me of the old EF Hutton commercials, "When EF
Hutton talks, everybody listens". I'll try to dig the book out tonight I spoke
about. I'm not sure on the K factor your using. Where did you get the factor
you used from?
Best,
Will
*** >>
Will,
Harris had no involvement with the WLW 500; RCA acted as the general
contractor, General Electric designed all RF and Westinghouse designed the
control
circuit, motor-generator sets, audio and modulator and all "iron" for the
project. RCA did assign a model number to the transmitter; the 500A. The person
doing
the preservation happens to work at Harris and has an intense interest in
this transmitter as I do.
The 500 kW was not fired up on the year 2000 but the Western Electric 7A
50 kW "exciter" for the 500 kW was. The 500 kW rig has not seen power in
decades. Too much of it has been scrapped out to ever allow the rig to work
again.
The k factor for the coefficient of coupling I'm using I got from an
iterative process using the standard formulas out of Terman for coupled coils.
for the
given circulating current in the RF PA primary k=0.143 gives me the proper
reflected resistance from the secondary back to the primary and it also gives
me
a Mutual that gives me a believable Es at the secondary that results in a
reasonable RF output voltage. The question is, is a k of 0.143 a practical
figure
for two coupled flat spirals, or is this much coupling too tight to be
practical?
Jeff Glass
Northern Illinois University
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