[Milsurplus] BC 639 and Bc 640

[C. Whitaker]

de WB2CPN
I thought you'd have some replies by now, but here goes:
The BC-639 uses the RA-42.  Their interconnecting cable
has  Jones Plugs on each end.  The BC-639 was used
in so many applications that a standard rack was whatever
was available.  The BC-640 rack included the cabling
between the slide-in units.  Starting at the bottom, here's
what you need:  First an AC mains control panel which
contained a 110/220 Autotransformer and a large "Variac"
to facilitate using various line voltages.  Then comes two
identical DC power supplies. Above them comes the
modulator panel, and above that there is the main control
panel with the power switches and the local mic input and
"key" lever.  The next item is the oscillator with two tripler
stages and one doubler stage, and above that is the PA and
antenna tuning stage.  Note that the doubler is coupled to
the PA by open space, (inductive coupling).  The rack has
air vents all up and down the sides and back.  Someone on
here a couple of weeks ago said they found a bunch of
639/640's which were still in their racks.  Good Hunting.
73  Clete