"David Eduardo" wrote in message
.. .
"David" wrote in message
...
On Sat, 30 Sep 2006 06:12:31 GMT, "David Eduardo"
wrote:
"David" wrote in message
...
It's still really old, which was my point. Bauer did not sell many
transmitters in that era. The 701B was a derivative of a "quick and
dirty"
model they built to fill the need of about 1,000 class IV stations for
new
transmitters when the FCC authorized 1 kw for them. I think they sold
something like 300 at the time, which was quite amazing. The 701B was
simply
an old-technology high-level plate modulated transmitter using, if I
recall,
glass envelope tubes... maybe the 4-500A.
KXIV and KRIZ both used the 707, in the '60s. KUPD got a couple in
the early '70s I recall. 4-400As.
I understood the B model at some point used 4-500's due to the relatively
short life of the US built 4-400 from EIMAC, and the transmitter's
inability
to use the European QB4-1100 (without major work), which lasted as much
as
5,000 hours more than the 4-400A.
KUPD was 500 watts all through the 60's. I do not recall the 701B having
a
power cutback in the stock model... must have been a modified 701 which
was
sold as a 1 kw only rig for upgrading Class IV station.
I said 707. A transmitter with stock outputs of 1 KW and 0.25 KW can
easily be restrapped for 0.5 KW.
I saw a bunch of 707's, and they were designed for Class IV stations
running 1 kw always, meaning they had no cutback switch. It was brought to
the market when the FCC approved 1 kw day an night for the roughly 1000
class IV stations in the US, and originally had no cutback. Was there a
model with such?
My mistake. I called a guy who actually built a 707 (and maintained several
other Bauers as well) and he said the 707 came as a both a fixed power kit
for staitons with one level and an adjustable second power selection for
those with multiple output levels.
Here is one without the cutback... a 1 kw daytimer on 1290 that had no need
for two power levels.
http://www.oldradio.com/archives/hardware/707.htm
The issue with using a higher power transmitter for lower licensed
fulltime power is that the FCC did not approve usage of such in the 60's
and a modified right was likely not type accepted (doable with paperwork,
though). A believe the rules did not allow more than 20% or 25% greater
transmitter power than the licensed power or higher power if licensed at
more than one power level.
The 701 superseded the 707, which was built for about 10 years, and used
4-500's. The B model was solid state in the exciter and audio driver, only
having 4 final and modulator tubes.