INTERIM REPORT NO. 4 RESEARCH AND DEVELOPMENT OF CACHE MARKER SYSTEM PHASE II: DEVELOPMENT OF ENGINEERING PROTOTYPE

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78-03153A001300030008-9
• Release Decision: RIPPUB
• Original Classification: C
• Document Page Count: 28
• Document Creation Date: December 23, 2016
• Document Release Date: April 30, 2014
• Sequence Number: 8
• Publication Date: September 23, 1953
• Content Type: REPORT

Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
CONFIDENTIAL -
SECURITY INFORMATION
INTERIM REPORT NO. 4
RESEARCH AND DEVELOPMENT
OF
CACHE MARKER SYSTEM
PHASE II: DEVELOPMENT OF ENGINEERING
PROTOTYPE
Covering the Period
15 June 1953 to 1$ August 1953
Contract No.
23 September 1953
This datiment contains information affecting the nationlIF
defense of the United States within the meaning of the
Espionage Laws, Title Sections 793 mid 74.
The transmission or the revelation of its contenta in anz
aper to e4g,.unAirthori;ed person is prohibited by ;al*
50X1
50X1
CONFIDENTIAL
4-sEcarry INFORMATION
Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
9
Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
. CONFIDENTIAL
SECURITY INFORMATION
ABSTRACT
? A portable Q-Meter detection system has been designed and is being
constructed. It will use an aural indicator instead of the meter used in the
original design. A rotating capacitor has been constructed using a clock motor
in order to eliminate one small electrical motor and associated batteries.
Some improvements have been made in the amplifier which give much higher gain.
The driver oscillator has been changed from a, Colpitts to a Hartley type with
resultant simplification of band switching and better stability. The packag-
? ing of the detector system has been given consideration and the prototype will
reflect some of our ideas on the eventual design. A s tudy has been made of
the batteries which should be used to power this equipment.
A crossed-coil system was built and tested with disappointing re-
sults. Work on this system was discontinued.
The design of coils and coil forms for transponders was finished.
The proper type of wire has been determined. An intensive investigation of
? packaging for the transponders has continued. At present a glass fibre re-
inforced plastic shell seems the most promising. Experiments leading to a suit-
able shell are being conducted in cooperation with a local plastics firm. In ,
addition, the consulting services of a polymer chemist are being arranged in
order to study methods of potting the coils.
-1-
CONFIDENTIAL
SECURITY INFORMATIAN
Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
-.CONFIDENTIAL
SECURITY INFORMATION
I. Q-Meter Detection System
The work on the 44-Meter detection system was continued with the
objective of building a prototype model which would be self-contained and port-
able. Several changes have been made since the first model was tested in the
field, and these will be described:
1. The Rotating Capacitor
The first model Which was tested in the field contained a motor..
driven rotating capacitor which WAS used to assure that the two tuned
circuits in the detector tracked together while searching for the trans-
ponder.'
? A clock motor has been built to drive the capacitor. This elimi-
nates the need for extra battery power to drive an electric motor and also
eliminates the electrical noise inherent in such a motor.
The two plates of the capacitor consist of two thin aluminum plates
cut to form internal teeth in a ring. Variations in capacity are accom,. .
plished by rotating a thin circular aluminum plate between them which has.
a diameter of 1.5 inches and has 20 teeth. It is staked to a small shaft
which is mounted in jewel bearings, as shown in the exploded views Figure 10
A Semca eight-day traveler's clock was modified to drive the rotat-
ing plate by mounting it so that it is driven by the last gear in the clock
train. The rotor shaft was mounted in balance jewels with adjustable cap
jewels. The entire mechahisawas mounted in a case made of methyl methacry.
late. In future designs the case Will be made or material more dimension-
ally stable. Also the hub of the rotor will be made of an insulating
material.
Interim Report No.
50X1
CONFIDENTIAL
SECURITY INFORMATION
Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
CONFIDENTIAL
SECURITY INFORMATION
GM' JEWEL SCREWS
GAP JEWEL
JEWEL BEARING
BEARING ,HOLDER
COVER _SCREWS 7
COVER
ROTOR HUB
ROTOR
ql`2'2)
FIG. I
SHAFT
JEWEL BEARING
BEARING HOLCEti.
CASE
EXPLODED /IEW - ROTATING CAPACITOR
CONFIDENTIAL
Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
CONFIDENTIAL
SECURITY INFORMATION
The clock work will drive the rotor for about one hour at approx-
imately 300 RPM.
In a production program it would be feasible to make the capacitor
plates by using printed circuit techniques. This would be economically
and mechanically desirable.
2. Aural Indication
The Q-Meter detection system described in Interim Report No. 3 is
being modified to provide an aural indication of the presence of the trans=
ponder. This is accomplished by utilizing the audio modulation of the RF
produced by the rotating capacitor. A pair of high impedance telephones
are connected across the crystal diode ahead of the RC filter. An audio
signal of approximately 430 cycles is produced by the rotation of the
capacitor. This frequency decreases slightly as the clock work runt& down.
In operation the input bias level of the amplifier is kept constant
and the oscillator drive is adjustable to produce an audible signal when no
transponder is present. The maximum sensitivity is obtained when a signal
is just barely heard in the phones. When a transponder is within the range
of the detector a marked decrease will occur in the signal and a null will
be produced. The effects of detector tuning and of the presence of a
transponder are easily obaerved by the aural indication.
3. Receiver Amplifier
The original Q-Meter incorporated a "window" amplifier in which the
major amplification occurred at the frequency of the oscillator. An R-C
coupling system was used in order to make the amplifier untuned. However
at these frequencies such an amplifier is not very efficient. Measurements
showed that the gain was only about. 150. It was decided to convert to an
50X1
CONFIDENTIAL
SECURITY INFORMATION .
Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
,CONFIDENTIAL
SECURITY INFORMATION
audio frequency in the first stage and amplify only the audio signals.
This has been accomplished by the circuit shown in Figure 2.
L. Oscillator
The investigation of oscillators which was reported in Interim
Report No. 3 did not take into account two important factors:
a. The voltage which must be supplied to the loads and
b. The band switching problems which are encountered
when providing for operation over a frequency band
from 50 to 150 ICC.
iiIikIt
The oscillator supplies energy to a low resistance Olen is parallel-
ed by the fluctuating lead of the series resonant circuit. In order to
achieve frequency and amplitude stability it is necessary to make this
load appear constant to the oscillator. In the Q.-Meter this is accomplish-
ed by making the value of low resistance element so small that variations
in the series resonant circuit impedance have little effect on the total
load on the oscillator. A value of 0.27 ohm has been found effective for
this purpose.
The complexity of the band switching circuits is affected by the
type of oscillator circuit used, the range of the tuning capacitors and
the width of the individual bands. A Colpitts oscillator requires a chinge
In the series capacity divider (coupling) for each band in order to main-
tain stable oscillations and necessary output. The Clapp oscillator also
uses a series capacity voltage divider. These changes in capacity add
materially to the difficulty of tracking the tuned circuits in the detector,
However the Hartley oscillator can :be switdhed from one band to another
with the least amount of difficulty. The detector now under construction
CONFIDENTIAL
SECURITY INFORMATION
Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
50X1
1..
Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9 SECURITY INFORMATIaN
c4
C29
?
U4
' C6
R7
'\AAAAA/
3V4
???.?????????..
R8
- AAAAAA0
C30
LI
RIO
MAAAA,-1/
C3
3
R9
RI I
/VvvVv\,
7
JI
612
L 2
C15
B2
?
C17
0
0
de
I U 4 2
53c
C18
ci9
fr -4r 41"
Sib
N.
20
S22
t2 I
C23
C.5
C26
S3d
ct
4
S20
I HI 11111 j
84
52b
R3 1R4
C28
R5
NO. . DATE BY
REVISIONS
PART NO.
SYMBOL
ITEM NO.
NO. MATERIAL
REQ.
PER
ASSEM
DESCRIPTION
BILL OF MATERIAL
MANUFACTURER
OR
EQU I VALENT
TOLERANCES
UNLESS OTHERWISE
NOTED
ANGULAR ?
FRACTIONAL ?
DECIMAL ?
ALSO USED ON PROJ.
?
NEXT ASSEM.
50X1
DO NOT SCALE THIS PRINT
0 METER
DETECTION SYSTEM
PROJECT NO.
DRAWING NO.
DATE
4 9/015 3
3034-101
2
Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
-6
? Vlo, ????."
'
Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
CONFIDENTIAL
tr,1L?
SECURITY INFORMATION
C)
PARTS LIST
Ci 1 Clo, 14i C23 - Arco #463 Trimmer Capacitor
-Arco #466 Trimmer Capacitor
C15, C22
C3, C, cs, c6, cll C8 $.C16, C171 C181 919, C200 -Arco #469 Trimmer Capacitor
C211 -Arco #469 Trimmer Capacitor
C11 - 100 uuf Silver Mica
C122 c13 1?0 uf @400\4 Paper
C25 4fluf to 11 uuf Var. Air Trimmer
C26 Special Motor Driven Capacitor
0271 Cap C30, 032, c33 - 0.02 uf
C29, 031 0.05 uf
Cto, 08c. Tuning
Cti Rec.. Tuning
a1- 150 K
42 - 200000 ohm var._
Rj, R4p, 115-. los000
R6, Ras R9, R11 - 1 Meg.
R7; Rio - 47o K
R1,2 0.27 ohm
? Bls B2s B3 - 1.5 1/ Battery
B4 - 135 17 Battery
J1 open circuit jack
Note: Band Switch is Shown in Position 2
CONFIDENTIAL
Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
I Declassified in Part- Sanitized Copy Approved forRelease2014/05/01 : CIA-RDP78-03153A001300030008-9
,C6TiiDiNTIAL
SECURITY INFORMATION'
will use a Hartley Oscillator and the? range of each band is being made as
large as the tuning capacitors will permit. It may be necessary to reduce
the tend width of each range in order to accomplish the required accuracy
of tracking.
S. Configuration of the Detector System
The two principal components of the detector are the detection coil
and the box which contains the electronic circuitry including the batteries.
When in use the box will be fastened to the waist of the operator. The
detector coil may then either be suspended at about waist height and
parallel to the ground or worn around the waist with the body of the operator
inside the coil. The latter arrangement would be more desirable Since the
coil could be worn under a garment..
It has been found that the Q of the detector coil does not change
appreciably when worn around the waist. However the changes in distributed
capacity are serious. An investigation will be made to see whether some
kind of shielding can be devised which will eliminate these capacity effects.
6. Packaging of Detection System
The design of the detection system should have the following ob-
jectives:
a. Location of the controls for ease of operation,
b. Arrangement of the components consistent with
objective a in order to occupy the least space,
and
c. Arrangement consistent with objectives a and b
which will make fabrication and servicing as
simple as possible.
CONFIDENTIAL 50X1
-.SECURITY INFORMATION
Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
Declassified in Part- Sanitized Copy Approved forRelease2014/05/01 : CIA-RDP78-03153A001300030008-9
,CONFIDENTIAL
SECURITY INFORMATION
By fastening the box containing the electronic components to the waist of
the operator both hands are freed to operate the controls. The main tuning
control and band switch will be mounted on top of the box. The amplitude
and fine tracking controls will come out through the sides. Since the
latter two are adjusted by ear, it is unnecessary to see them. The present
model is being built with these objectives in mind. Details will be given.
in the next Interim Report.
Fbwer Supply
There are a number of different *Inds of batteries that can be used
to supply the power.needed to operate the detection system. In choosing the
kind of battery that is to be used, consideration must be given to weight,
size, dependability, operaticin at low temperatures and cost.
The model of the detection system which is presently being built
will use dry batteries which are readily available. It would not be diffi-
cult to change to another kind of battery if the same voltages and currents
are available for the same Space.
There are batteries available, manufactured by the Burgess Battery
Company, of the silver chloride-magnesium or cuprous chloride-magnesium
construction which are water activated batteries. In the dry state, they
have a very long shelf life. They become activated by putting them in
water for one or two minutes. The: water need not be distilled. Tap water,
lake or sea water will serve equally well. -These batteries must be
activated above the freezing point of water, but they will operate at
ambient temperatures from -60?F to /1500F. Compared with dry batteries
of equivalent electrical characteristics, the water activated batteries
are lighter and occupy. less volume.
9-
CONFIDENTIAL
-SECURITY INFORMATION
,! Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
50X1
Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
, CONFIDENTIAL
SECURITY INFORMATION
? ma no nanihriall?Elnine -,
ma
9 Isiiitil"hirOr Hilb+-
Liihihrliiii4
mu_ __ .
in
IN d mi al d1111:45444qmilui
I
III 1111111FRIIVE111P711::481.11:111.
USW
? II II MI P.4 "Mini
01111ff thilindidebilin""1"1"81.481128railliarNEillha
1 OH 111111111111101 Ills 1111F;
I
o Hpoinostut,rePF;PINEN
MI 11001111111111NONI
11111 RMINIVEM
MI Pg
r si ?
%IL/ IPH"qq litre Id .11,G;;;;;enr.
. . ... , wail
400. 20 40 60 60 100
tEmPERATucrE IW?REES FAI4REN4EIT
ffects of Temperature on iDry Battery r
Perf,,rnthiwc..
Figure 3.
50X1
CONFIDENTIAL
-16- SECURITY INFORMATION -
Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
Declassified in Part- Sanitized Copy Approved for Release 2014/05/01: CIA-RDP78-03153A001300030008-9
CONFIDENTIAL
SECURITY INFORMATION
'
The effects of temperature on dry batteries are given in a U. S.
Department of Commerce publications LC965, 11/15/49, entitled "Electrical
Characteristics of Dry Cells and Batteries (Leclanchil Type)". The important
factors are storage and operation under adverse temperatures. Storage at
above normal temperatures its detrimental to the operation of dry batteries.
Low temperature storage preserves the life of the battery. The effects of
temperature on the performance of 'dry batteries is shown in Figure 3. The
internal resistance of the battery as a function of temperature considered
in conjunction with the load requirements determines how low in ambient
temperature satisfactory operation will still occur. The open circuit
voltage remains substantially the same firnm -40?F to / 110?F. The capacity
of a dry cell varies with temperature being 27 per cent at 0?F as compared
to that obtained at 70?F.
It can be concluded that dry batteries which are fresh or hate been
properly stored will work satisfactorily at ambient temperatures of 0?F or
with a shorter life (about 10 per cent as compared to 70?F) at -10?F. If
it is anticipated that operation of the detection system will be needed
below this temperature or that obtpining fresh batteries is a problems
then either water activated or meicury batteries should be used.
CONFIDENTIAL
11- ';SEGURITY INFORMATION
Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
50X1
Declassified in Part-Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
CONFIDENTIAL
'SECURITY INFORMATION
Crossed-Coils System
? A Detectron Model 711 Meta3. Detector was purchased to determine
whether the conventional metal detector could be used to detect a transponder.
? This metal detector is similar to the crossed-coil system except that it operates
? at only one frequency. It consists of two coils, mutually perpendiculars One
is the oscillator coil and the other is the receiver pick up coil. The oscilla-
tor is of the Hartley types operating at 100 KC. The receiver consists of a
tuned RF amplifier followed by a detector and three stages of audio. The de-
tector consists of a mixer stage with a local oscillator to give a difference
frequency which is audible. The two coils are each shielded by a rectangular
box whose sides are metal except for one side which is wood. The top and
bottom are made of masonite. The control is adjusted for a null by Ff balancing
? out stray capacitive coupling between oscillator and receiver through the
ground and surrounding objects. The control changes the orientation of the
receiver coil, which is pivoted about two points. The position of this adjust-
ment for a null changes with the position of the detector with respect to its
surroundings.
? A transponder was tuned to the same frequency as the detection;i
system in order to determine the ability of the metal detector as a transponder
detector. It was found that the transponder could be detected at a maximum
distance of ten feet.
Efforts were made to build a variable frequency crossed-coils
detection system. The only possible advantage this system would have over the
Q-Meter detection system is increased sensitivity.
CONFIDENTIAL
-12- -SECURITY INFORMATION
Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
,
50X1
Tv'. ?
17t1.' 'Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
CONFIDENTIAL
SECURITY INFORMATION
RECEIVER
Fig. 4 A Crossed Coil Detection System
-13-
CONFIDENTIAL
Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
JI4
Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
CONFIDENTIAL
SECURITY INFORMATION
The circuit shown in Figure 1 was built up as 4 crossed-coil system.
The principle of operation is as follows. The oscillator in the receiver is de-
tuned from the transmitter and receiver coil by an audio frequency. Thus, when
a transponder is present, the received signal from this source is mixed with
the receiver oscillator signal to produce an audio output. The filter network
in the plate of the converter then allows only the difference frequency' to pass
on to an audio amplifier.
In this first version, several difficulties were encountered, The ,
.most serious were that the receiver oscillator coupled or radiated into the
receiver coil, and the transmitter apparently interacted with the receiver
oscillator because of the nearness of the two frequencies. The overall effect'
was to produce a poor null with no transponder present and poor sensitivity
when a transponder Was present. With the system operating as shown it was
possible to detect a transpander.of a maximum of about three feet. With the
addition of an amplifier after the receiver coil, the sensitivity was increased
to approximately six feet. However, this modification did not completely
eliminate the poor null.
Another difficulty encountered was the capacity effect. The added
capacity present due to a person standing near the transmit and receive coils
shifted the frequency with each movement of the person. In an effort to elimi-
nate this effect an electrostatic shield was placed around the transmitter coil.
--
Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
This greatly improved the operation; but, here again, the effect was only re-
duced, not eliminated.
In view of the limitations of this type of circuit, particularly
the problems encountered because of the nearness of the transmitter frequency
to the receiver oscillator frequency, it was decided to construct a super-
lietrodytte receiver. Such it( tedeiver was construct-ad-taploying- a- 175 KC -IF -and- a BFO.
-CONFIDENTIAL
;SECURITY INFORMATION._,
50X1
Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
,
.1
.CONFIDENTIAL
SECURITY INFORMATION
The front end of this receiver proved to be very insensitive. The ,
first detector consisted of a 1R5 and was preceeded by two stages of RF ampli-
fication using 1%1s. In an effort to avoid a tracking problem the RF ampli-
fiers wenamade RC stages. However the gain is limited to lass than ten per stage
over the frequency range 50-150 KC because of the large input and output
capacities. The real difficulty, however, was found to exist in the first de-
tector. With a relatively large signal present on the signal grid of the con-
verter tube) indicating the presence of a transponder, a small and very broad
signal exists in the plate circuit of this tube. All attempts to correct this
condition by changing the parameters in the converter stage have been unsuccess-
ful.
No further work has been carried out on this circuit because of the
accelerated pace established on the Q-Meter detection system.
-15-
CONFIDEUTIAL
'SECURITY INFORMATION
Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
50X1
Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
CONFIDENTIAL
SECURITY INFORIKAT ION
Transponders
1. Coil Forms
The design of the coil form has been based on the following factors.
The outside dimension has been determined by the requirement that the
transponder must fit into an air drop container whose inside diameter is
slightly larger than fifteen inches. The shape of the coil form, consist-
ing of a rim with three rows of pegs placed around the periphery, is one
which produces a high Q coil with the wire distributed to give a high
mutual inductance with respect to the detection coil. An experiment com-
paring the Q of il of the design described above with a coil of single
layer solenoid type construction of comparable diameter, using the same
number of turns of the same wire, gave a Q of 400 as compared to the 15
? obtained for the single layer coil.
? Measurements weie made to determine what effect staggering the pegs
? would have on the Q of the transponder. Making the coil form in this way
reduces the spacing between turns of adjacent pie sections of the coil.
No difference is Q or inductance was observed. It did make winding the coil
? a more difficult process.
? To simplify the molding of this form, it was decided to make the
coil form out of three identical pieces. This requires a mold without any
under cuts and keeps the cost of the metal dies to a minimum. The individ-
ual pieces of the coil form (see Figure 5) are supplied with dowel exten-
sions and holes which permit easy assembly. The material that has been
suggested by the molding companies is styrene, which has good electrical
and mechanical properties, and which allows easy cementing of the pieces
together.
CONFIDENTIAL 50X1
'SECURITY INFORMATION
_
Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
CONFIDENTIAL
SECURITY INFORMATION
Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
COIL FORM
t.-
1:620
50X1 5
-17?
Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
CONFIDENTIAL
SECURITY INFORMATION
Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
ONFIDE4TIAL
SECURITY INFORMATION
The replies to our inquiriei for making the metal dies and molding
the coil forms quote a price range for the metal mold for injection mold-
ing of $990 to $4625 with an estimated time for completion of 12 to 14
weeks. The prices per molding for quantities of 1000 vary from $0,0359 to ,
$0.75, and in quantities of 10,000 from $0.287 to $0.65.
2. Wire
Measurements have been performed to determine the properties Of
transponders made of coils whose outside diameter is 141 inches. Four
transponders were measured, each wound with a different kind of wire. The
number of turns was determined by the wire diameter, the maximum possible
number of turns being used in each case. The different wires used are as
follows:
No. 1 - 105 turns of litz wire consisting of 50 strands
of No. 38 where the strands are merely bunched together.
No. 2 - 60 turns of litz wire consisting of 25 strands
of NO. 30 where the individual strands are braided on a
glass fibre core.
No. 3 - 90 turns of litz wire consisting of 64 strands
of No. 38 where 8 strands are braided together to form
a cable and then 8 such cables are braided together.
No. 4 - 99 turns of No. 18 solid wire formvar insulated.
The wire for the first two coils was supplied by New England
Electrical Works. The wire for the third coil was supplied by Belden.
The first coil that was wound for No. 3 transponder had only a Q of about
50X1
CONFIDENTIAL
-18- 'SECURITY INFORMATION
Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
Declassified in Part-Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
.1
. CONFIDENTIAL
SECURITY INFORMATION
100. Measurement of the DC resistance indicated a value four times as high
as the calculated value and measurement for continuity indicated 75 per
cent of the strands were broken. Careful selection of the 9000 feet of
wire from Belden resulted in a piece long enough to wind a No. 3 coil which
was free of defects.
This incident points out the difficulty in braiding wires as fine as
No. 38. This difficulty has not been encountered with litz wire made of
No. 38 where the strands have been merely laid together and wrapped. The
New England Electrical Works has informed us that No. 38 could not be
braided without breakage on his machines. On the other hand, the fab-
rication of litz wire using No. 30 braided is no difficult problem.
The Q of each coil was measured as a function of frequency. The
results of these measurements are displayed in Figure 6. There is a dip
which occurs at 120 KC 'Which has been indicated only by the experimental
points. The smooth curves drawn ignore these points. The cause for this
dip has been attributed to the NSS transmitter at Annapolis which operates
at 123 KC.
In order to detenaine the relative merit of these coils, i.e. their
detectability, the Boonton Q-Meter and the coil which was designed for
the detection system was used. The Boonton Q-Meter was adjusted to measure
the Q of the detection coil and the transponder coil was then tuned through
resonance and the change in Q was observed. The transponder coil and the
'detection coil were maintained parallel with their axes of symmetry colli-
near. Readings were taken of the change in
for frequancies 10 KC apart
from 50 to 150 KC. The results arp shown in Figure 7.
CONFIDENTIAL
-19- ,S1.3cp.43:ry ppronk_tATION.
- Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
50X1
6-8000?000C1-00VCSI-00-8LdCl-V10 1-0/90/171-0z eseeIej -104 panaiddv Ado paz!l!ueS u! PeWsseloaCI
Tit IIIMI2INO0 -0Z-
;
,
' , -
I"
iLt
, ,
MEM
II,
----_-.4.
:-,1-
,-
-;
.
,
, ..
it-
iftrm-
1..=
'Bill
4,
: tz
- .
; t
tii
-tli-
uto
gin
"rirssamumum:
tramranuiP
:
I
11 ?
. ?
--
Ell
f-' f
- 1-
u
.
4- -
: :.
1.-r
4:-
.
?
4
+ '
.1, t
I .:
Remo
&....:1A
ord
--;
/
'
4
, t:.
I 44"-
1 '
Ni
tri
"LI
,.4
.
LI:
.
'1-.;
'4.4.41
Ts:
1444
tilal;Ttl
414
1T,
F.,4.
. ' .I
1 :
iffiiiii.
rift
I
.,:t.::
Dn.
1
+,,
loct-:-:
trz.t-r
?
L.T...1.4:1
--
s
?? ?
:1
?-?:;
t
.4:4'
,
14.
?
: ?-4
?
4 *
L.i
'''
?
.
?
I
tt
t 1-
?
I r
t .
ifit
I :
Nig
Milli
uir.:?-+
'I
"1 I-
t.:;T:
;11-
, ? T
1-41
t! 4-:
1111
; II:4
ow
li,s

U
.
ne
SS
.
1-1 4
? .
Iltri:1
-
'
, ..
NIE
+/ 1
'
t
-I
?,-! -.1,1
4
i? ?
11-1
?-?
.
:
14?
:-1_
+
,N-MIE1-:'
t-.
1:4
i ,
:44
.
Er
-.
Eill
.1.
_t..
An
El
.
i I.
rtl 1
;,
"f
?
i
If
,- ? ,
rt
+1-4
:lip
, I
'I+
4
f
.1
?
el
fT:4
1-1-?
0
, ,
?.1:-.
hf:
t:h-
4
'
r 1
14
4...
'
? ?
MEE
-1:
--1?
"r
:
-?
[?'?
.f
?
?
..,
.
"V
t ?
I I '
' 4
.
1-.1
,; ?
? ?
1
,,,
..?
..
t +
I
. .-
II-
Lt--T.
:1-f-'
4141
?
V
-'0 IflPi":
ALANItgl:".
.
'I
'
lt
..
' F.P1111"
??
.8.4
..MINI
: . ? ?
' 'T
-:. .
, ..
WM' ?
ii
t 4 f
reiln
M
111
?
4 ?
Z ?
?
. ? .
l?
g
1.1,417?21.4'
' .
.
.
? ?
.:*
. ,
? ?
4-4 ?
I t
i.4
1
t...
:
Ild
.
-? 4-
4 t .-
4 ???
? t1
444 +
+.4ill
't

.. ....,
INE
MEI
414
Lai
so
11.
?/????
P? 4
: 444.
, -
.2 17,1
1411;
0.4. ???
.
t 4
.
: . ':
4).?
,..
INA
_
1
.
.. s ?
i
0
-
,
M
1111111111111E1/1111
EI
ENE-
MEIMEIMMLor......._11.1IMERINEnip
ME
MilliMar.-7:41.--;r:?..
M
Tsminimommon
? ????.?..4.4.4.?
:
???444/144.1111.4
2.111diall01111
MM
IIIELAS
.4
? ?
*.. 4
?
44 41:
.?
f r?
ail
ME
E
il
?
?-..../1
1
4:.
?-4 ?,
,
4
dim/
.4?V
.
tINI
?
t
'. .
I
IIRI
? ?
- ?
.-
..? ..
,-i--
By
.,
-?-?-?
"
0
0
.
?
4..!
,? ..
f.,-...-
,?,,
1
? ?
. 1 ?
i ,.:
? ? 4
. 4
....
?
1
444 ? ?
. :.
? . .
?
?
?
' t
? r '
. ? .
. ?
i
4
11E11111111.1111M
:4,7.-ti
ME
1.
MINNINIMEN1111
?
"....
42:44

7: -.T.
; I: 4
? ? .

..

.?
.? .
.!ii

wumo
m.
r.M
?,. ,;4
14
1
IM?
m.1.1
ommnomil
3i.:
i.
.i
Aramis......111.
11.11111111111111111111111111111111111.
1111?.
IIM
.,........
1111111111111.111.1111.111E
NIA?
.
?
:
? .
t.t.
ETA
M.?
i ?
IMEI
EEE?
1111
ENNAN
1111111rAll
T.
1.: ?
A
Mir
E. ?
-
.
'ME
NM
.,.....
:1.".H
L:i--:-:--
? 4-
.. ,
?
.,._,..,
..,?
.,,,
m
En,
.
Ems
.....
smimmionsurdi
?
spry
r
1 ?
.,
. .
.'.
?
. .
fen.;
? -
amm
.
f 1

,.
?
s' ?,-
7.
-
,
? :2,
?
.
,--?
:::
?--r .
-.-.
, .
...,
..
4 r
..
0
+._ ,
? ,
::,
4
: : ?
CA
, -''
_,..,...?
. .
-
::,.
.?
.
___?,.
1-1
rt-,,
.
?
? ? i
4 . f
t
M
. ?
&II
?
-* '
. ,
4,
???
A
,f
tt
-:'!i
-..
'?I?
? I,
?
f 't
"4,1
, ,
? Il .
.
.,-.
i....
.._...
t.4 it
?-?.,
n'
1111r11
.
?
i:
.41t
.
t
I
E?:21
?
1
..4:1.
r 1
-.
? .--,?

?:
MOW-
6arib
Itt.
t t
MR'
IL:1--
A.'"
;._:it.
iim
M
41
1;1.
,..
i? i
t I
I'
,..
? 4
1 ?.?
'''
.11C401111FM:ii
IMMIL.
.,
1144-
. .
? ?
? f 1-1
? ?? ?
}EellKet
...41.-
ANN
?- ? .
.. .
.
...
r?-1--1-
: . ? :
? ?
' :!.
? * ?
:?.-; !
?
:: ?
? Neill
rtifilE
'1"11;1
1.!!!!
.
. .
El
El"
L ??
? ?
. ,
M
01
1??
4444 4-4
XV;
,
?
NN
. .
. f 1 1
7T:
ME
01.111110111.
? ?
11111
? i'?
? "
iiii
N:
i4.--.4:
:":
...:4i .4-
._.
""
? :
1
?? ,
?
'
1
-
I ? ?
t:
'
t
L.!,
4?4
.4.
!
i .,:.
??-?
I. ;
,
: . -
?
-.I-
?
"
;1-?? 4
t?t.
" ?
?4
t't?
.
441
UN
t.
1U Te
6-8000?000? 00VCS CO-8LdCI 1-`9'10 0/90/17 aseala -104 panaidWikellia'r;;Zw".fiV:i Li! PewssePeci
.1.11 IdAltallitS.111./L)
Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
orsuunii unrui
Ennismosimogriordmik
MMI
Es
U.
EIMINVVINIERMIU
11
immEnsworminommensima
MINENWEranal
mourols Emmimminams
mormimmummiwirsousam
onimesmhommingssi
Nraiiim-msmisimmommim
mommosommon
mmomms MIENIMMINIMME
ME Eli MEE
I1HIIEIMMEMENNEMIN
ffltlluItIO TMI MIMI
?
-4?? ? . 1 . 4
*1: ? "
11114
REIM M
WNVAIRlffIWMWIPIUE
ISEI4 IDII1I Elliin IN ME
II 1 MI
-21- CONFIDENTIAL
Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
Declassified in Part-Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
J
CONFIDENTIAL
SECURITY INFORMATION
_
30 Packaging
There appear to be two main avenues of approach to the problem of
packaging: the shell type structure, or potting in a casting resin.
Shea Type Structure
This method of packaging consists of placing the tuned circuit in-
side of a case made of a material which has good mechanical and electrical
properties. It was mentioned in Interim Report No. 3 that the use of a
foam-in-place plastic was being considered as a core. Lock foam appears
to have suitable electrical properties, but it is not only expensive both
in initial cost and the cost of handling it in the production of trans-
ponders, but it is believed to be unnecessary in that the glass fiber re-
inforced plastics that are being considered for the shell have more than
sufficient mechanical strength.
The design of the shell that we are considering is shown in Figure
8. The major problem in the design of the transponder case is that of the
joints or seals around the inside and outside diameter. They must be of
such a nature that accidental. dropping will not result in large forces
tending to pry them apart. This would be the case if. the same lip for.
sealing which is used on the inside diameter was used on the outside dia-
meter. The increase in diameter of the case, beyond that 'of the coil, is
another objection to this type of joint for the ouside diameter. The seal
for the outside diameter consists of a butt joint with an overlapping strip
around the outer circumference. This allows the use of symetrical pieces
for the case which keeps the cost of tooling down. If Very large quantities
of transponders are anticipated, then there would be advantages to making
the pieces unsymetrical obtaining an overlapping joint without the use of
a sealing band.
CONFIDENTIAL
-22- SECURITY INFORMATION
Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
50X1
mo!tvvpiom ,umpo3s
Tc11.11\1301.A103
E.D.O. I REV.
DATE
NO. I LET.
I BY
CHANGE
REVISIONS
SUPERSEDES
AS OF
ALSO USED ON PROJ.
mCI1 '
(f)
3
Ft 1) Z Z
. 5
? 7) met
? n's \-- * 16
iti ?C t
-ili in
P1
>
(A
I
min
mmo?.
MATERIAL J DESCRIPTION ,
BILL OF MATERIAL; t I
DRAFTSMAN ..Zief
DESIGNER
PROJ. ENG.
CHECKER
SPECS.
6-8000?000?1,00VCSI-00-8LdCl-V10 1-0/90/171-0Z eseeIej -104 panaiddv Ado paz!4!ueS u! PeWsseloaCI
(Mrvg
9-2/J
- NOV/ 97. -7S?
?"V
,IcI) 7/D
no
. ,
9/7 ?Pt 5:-
? /
\
\
? .201.Y/
mpv-3 ?fr
?
? io
f
e?*"
?
40-1
? ? 6-8000?000?1,00V?91-?0-8LdC11-V10 1-0/90/171,0Z eseele -104 PeAo-iddV Ado ? Pez!l!ueS - 4-led LI! pawssepaa
-
kumno3s_
Tvi1l.N3a1.11\100
Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
CONFIDENTIAL
SECURITY INFORMATION
ti
Inquiries have been sent out to a number of companies which make
glass fiber reinforced plastic molding. Thus far, only one company has
been heard from: the Apex Electrical Manufacturing Company. They sent a
representative to us to discuss our problem. He told us that the cost of
the dies for matched metal molding would be approximately C000 and the
cost per half shell about $2 in lots of 1000 which would be sufficient to
make 500 transponders.
In order to test some transponders using this type of structure,
the W. R. Chance Corporation in Arlington, Virginia, was contacted. They
Aske fiber glass reinforced plastic boats as well as containers for elec-
tronic equipment for the Navy, using hand layup and vacuum bag techniques.
The results of the tests which will be made in transponders encased in?
shells made by these facilities will determine the course taken with re-
gard to large production facilities.
Potting
>
This method of packaging consists of casting the tuned circuit in
a solid block of material. The material used must have the necessary
electrical properties so that the potting process does not substantially
alter the detectability of the tuned circuit. The mechanical properties
must be such as to provide protection from. any of the environmental con-
ditions which exist during Storage, transportation and burial. The re-
quirements for low dielectric losses appear to be more stringent for the
material used for solid casting than for the shell structure because of
the close physical Contact of the potting material with the wire of the
coil.
-CONFIDENTIAL 50X1
4- SECURITY INFORMATION
Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
CONFIDENTIAL
SECURITY INFOMATION
One of the materials that we have considered has been Cerese AAA
wax. Our experience has indicated that the electrical properties are well
suited for our application. At room temperature the observed mechanical
properties are sufficient to withstand rough handling such as accidental
dropping. Measurements were made to determine what would happen at high
and law temperatures.
A one inch cube sample of the wax was placed in a water bath under
6 psi. The temperature of the bath was raised until deformation pf the
wax sample occurred. The wax sample deformed at 168.8?F. No deformation
occurred below this temperature. A similar sample was placed in a.
refrigerator reducing its temperature to 18?F. The sample was immediately
placed in a vice which was tightened to the point where the sample was
completely deformed. This occurred without fracture, indicating the
material remained tough at this temperature. A transponder cast in the
wax dropped from four feet to a concrete deck cracked when it landed on
edge but remained intact when it landed flat.
Another one of the materials which has been considered is the AN-5
casting resin. A small simple was cured to become familar with handling
this material. It cured at-50?C in 48 hours. The sanple was found to
be quite brittle in that it fractured when hit with a hammer. A trans-
ponder was cast in this resin, requiring about four days at 50PC to com-
pletely cure. The potted transponder was tested electrically, and it
appears to change little due to the. potting. No mechanical tests have
been made; but from the experience with the transponder cast in wax, it
is expected that it will not withstand a four foot drop without fracture.
-25- CONFIDENTIAL
SECURITY INFORMATION
Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
50X1
Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03153A001300030008-9
-CONFIDENTIAL
,SECURITY INFORMATION
In order to investigate thoroughly the potting technique as a-means
of packaging, a polymer chemist is being hired as a consultant. He is
employed by the Atlantic Research Corporation.
Program for next interval.
1. The work on construction of the new model of the (i-Meter detection
system will continue.
2. The work on packaging of the transponders will continue. It is ex-
pected that transponders packaged using the shell structure will be ready
for tests during this period.
30
Experiments will be performed to determine whether the detector
coil can be effectively shielded 30 that it can be worn around the waist
of the operator.
-26- CONFIDENTIAL
SECTJR in INFORMATION
Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 CIA-RDP78-03153A001300030008-9