[Boatanchors] BC-639/640

[revcom at wbsnet.org]

Morning...

Reading the posts on the BC-639 and subsequent BC-640 I could not help
but chuckle remembering my experiences and had to dig out my old CQ
publication -Surplus Schematics Handbook-, pub 1960.  I had a friend that
had one of these and his experience is exactly what the author states:

"The BC-640 is ground type, rack-mounted transmitter for the 100-156Mc
band for general communications with aircraft.  It is amplitude modulated,
providing 50 watts output over the band.  Provision is made for the use of
tone modulation when MCW operation is necessary.  Operation is crystal
controlled, with frequency changing being accomplished by changing the
crystal and the circuits.  Crystals used are in the 5555.5 to 8666.6 mc
range, for a total multiplication of 18 times.  Various sections make up
the complete transmitter and each is individually removable for repairs.Input power is 110-220 volts 60 cycles single phase.  Minor differences
exist between various models such as the addition of dial locks, and the
reduction in the number of meters employed in the BC-640(B).

This is the biggest, most powerful TVI generator ever built, and with
slight modification will be able to completely blank out all vhf and uhf
channels for miles around.  This gives TVI even when turned off."

My friend had one of these in Salina, Kansas, back in late 60's.  ALL TV
was off the air then, and weak at best in that area. We put up dual 10
element beams at 60 ft.  Fred fired that sucker up and tried to contact
stations in Wichita, 80 miles to the south, and as it says, he "creamed"TV all over Salina and even Lindsborg, 20 miles south.

We tore it up for parts.

Rod
K0EQH