ENGINEERING MEMO RE: MODIFIED SYSTEM 1 INFORMATION AMPLIFIER (MP 70641)

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP81B00878R000200050025-3
• Release Decision: RIPPUB
• Original Classification: S
• Document Page Count: 2
• Document Creation Date: December 9, 2016
• Document Release Date: February 16, 2000
• Sequence Number: 25
• Publication Date: August 21, 1958
• Content Type: MEMO

Approved For Release 200
To:
W P-2 )
AU:
WRSP-3 )
info; Headquart
Subject: Engineering Memo re: Modified System I Information
Amplifier (MP 70641)
P81 B00878R000200
25X1 A
/
500254j /
CMCC 151X5.1219
Copy ,3 o14
21 August 1958
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Bah detachments have noted that the amplifier gain could be
aced 'by changing the physical location of wires and parts. The
variations were erroneously attributed to changes in degenerative
lng between input and output.
The true cause of the gain variations was found to be caused
by the changes in stray capacitance to ground. A favorable lead and
parts layout would reduce the stray capacitance, increase video band
width and, therefore, increase the amplifier gain for pulse input signal
An additional modification to the amplifier should be made,
and a permanent note should be added to the amplifier schematic.
ATIOlki; Remove capacitor C926 and discard.
This capacitor is paralleled across the plate resistor of the
t stage in the amplifier. This capacitor is not required and it
uces the video band width. With this capacitor removed, the
frequency response should conform to the curve shown in the
m 1 Field Service Bulletin No. 2.
SP-
I. The tole ranc
third local oscilla
millisecond* t
urn interval of the System 3
1.5 milliseconds) is
corxds.
The bias adjustments
described in the instruction
ta reduction equipment as
uals are correct.
WRSP-3 has noticed that Occasionally the voice readout tape
does not make a voice announcement on the first count on the
second or third loading during a complete duplicating process.
Stated in another manner, for a normal mission it requires
three reels of I-mil tape to duplicate or copy the information
contained on one reel of 112-mit tape. The VRO tape always
makes the first-minute voice announcement for the first of
the three duplicate reels, but occasionally there is no
first...minute announcement on the second and/or third reel.
Approved For Release 200ggRA7RDP81600878R000200050025-3
This document contains information affecting the national defense of the United States within the meaning of the Espionage Lows, Title
18, U.S.C., Section 793 and 704, the transmission or revelation of which in any manner to an unauthorized person is prohibited by law,
Approved For Release 2000SECRETDP81600878R000200050025-3
CIACC ISIX5.1 Zt 9
Copy 3 of 4
4.
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21 August 958
To be certainthe cause, the equipment would have to be
cbek while It was malfunctioning. The factory has one
suggestion. as follows:
ports are switched to automatic
, there is a one-minute time-delay
y wired in series with the automatic transport
ol functions. After the first reel Is
cempleted, the voice readout transport reverses.
The lay relay will not permit a voice annou c
orded for the first 60 seconds after
The time delay has no correlation with the
Perhaps the time delay relay prevents the first-minute
voice announcement On the second and third reel. Try
tilewing more time before starting the second and third
dupe.
the factory does not have the distribution schedule
eduction equipment, it is our understanding that
nt C will aot receive II and IC racks.
25X1 A
Approved For Release 2001 PPWCDP81600878R000200050025-3 A
This document contains information affecting the national defense of the United States within the meaning of the Espionage Laws, Title
18, U.S.C., Section 793 and 794, the transmission or revelation of which in any manner to an unauthorized person is prohibited by low.