[Milsurplus] Old CPUs

[C.Whitaker]

de WB2CPN
Some Trivia:  You know why GCA sets, MPN-1's I know, precision tracking
at about 9 Gigs, used a loooong section of wave guide between the magnetron
and the antenna waveguide switches?  Very high level engineering, those 
Gillfillian
guys.   The magnetron was highly susceptible to frequency pulling if it 
encountered
a reflected wave from the load.  The waveguide switch generated a lot of 
those,
so, they just made the waveguide long enough that the magnetron finished 
firing
before the reflected wave, (VSWR), arrived back from the antenna.  When they
improved magnetrons the extra waveguide was bypassed, but not removed.  In
case you're wondering, that extra section fitted behind the precision 
horizontal
antenna compartment. 
73  Clete