[Milsurplus] Old CPUs

[D C *Mac* Macdonald]

When I was a student at USAF's Basic Navigator Training School
at Harlingen AFB, TX (Jun 61-Mar62) I was also a USAF MARS
member.  Somehow, the base had an AN/MPN-1 GCA that the
MARS members disassembled.  I salvaged a bunch of RG-9B/U
coax from the task.
 
Somebody said that unit had been used during Berlin Airlift,
but that is probably just an urban legend sort of thing.
 
73 - Mac, K2GKK/5
(Since 30 Nov 53)
Oklahoma City, OK


 
> From: raydio862 at verizon.net
> To: whitaker at ieee.org; milsurplus at mailman.qth.net
> Date: Sun, 31 Jan 2010 08:55:29 -0500
> Subject: Re: [Milsurplus] Old CPUs
> 
> Interesting, I've heard of that before, are there any MPN-1's in existance 
> anywhere?
> Ray
>
>
>
> ----- Original Message ----- 
> From: "C.Whitaker" <whitaker at pa.net>
> To: <milsurplus at mailman.qth.net>
> Sent: Saturday, January 30, 2010 8:30 PM
> Subject: Re: [Milsurplus] Old CPUs
> 
> 
>> 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