TECHNICAL PROPOSAL NO. TP-5500-2.7 (SANITIZED)CRYSTAL-VIDEO ANTENNAS

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78-03424A000200020005-4
• Release Decision: RIPPUB
• Original Classification: C
• Document Page Count: 11
• Document Creation Date: December 22, 2016
• Document Release Date: August 11, 2011
• Sequence Number: 5
• Publication Date: July 1, 1955
• Content Type: MISC

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TECHNICAL PROPOSAL
NO. TP X500-2.7
NIQ
CRYSTAL-VIDEO ANTENNAS
Prepa.r"ed for:
July 1955
Revisedt August 1955
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TECHNICAL PROPOSAL NO. TP-5500-2.7
I CRYSTAL,-YIL)BO AN ENNAS
INTRODUCTION
This proposal includes the design and packaging of nine
antennas and crystal holders to cover the frequency range from
50 megacycles to 40,000 megacycles. This frequency range is
-broken up into the following bands : Band 1, 50 - 110 Mc; Band 2,
110 - 250 Mc; Band 3, 250 - 500 Mc; Band 4, 500 - 1,000 Mc;
Band 5, 1,000 - 2,200 Mc; Band 6, 2,200 - 11,500 Mc; Band 7, 4,500 -
10,000 Me; Band 8, 10,000 - 20,000 Mc; Band 9, 20,000 - 110,000 No.
Four antennas will be required for each band. Each antenna
should have between 80 - 1050 halfpover beamwidth, low VSWR and
axial ratio with design goals of 3:1 or better. The design goal
is to achieve at least 115 dbm tangential sensitivity in each band.
The. discussion to follow is divided into three parts. Part I
is a detailed discussion of the antennas proposed for this system.
Part II is a detailed discussion of the crystal holders to be
used in this system. Part III is a detailed discussion of the
over-all packaging of the.final system.
PART I - ANTBNNAS
As_a result of a eonferenpe attended by Navy representatives,
the following program is suggested for obtaining
a satisfactory system of antennas and crystal holders to cover
the bands specified above:
a . ' Bands 1 and 2 (50 - 250 Mc . )
If one antenna can be used for these two bands, the
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packs ginre problem will be greatly reduced. Therefore,
this proposal considers only one antenna for Bends I
and 2 and every effort will be made to permit one
antenna to cover the full range. This antenna will
be vertically polarized.
There are five alternatives at the present time which will
be investigated. They are:
1. Resonant dipole in front of absorbing plate or reflecting
tees will be furnished by the Navy. O will fully evaluate . 25X1
screen
2. Modified discone in front of absorbing elate or refrlectin
screen
3. Quarter suction discones backed by absorbing elates
4. Resonant bow tie in front of reflecting screen or absorb-
ing plate
5. Spiral antenna
Scale models of the resonant dipole and modified discone
these models and, if successfal,will then build full scale
models and test these. If the original scale models fail, the
remaining three alternatives will be'investigated (at higher
frequencies for convenience).
b. Band 3 (250 - 900 Mo
The conical helix developed.by0 may prove satisfactory- 25X1
for this band. This helix has the follovinr* character-
istics as measured in the range 450 - 5,000 Me. for band-
vidths of over 2:11
1. Very ivy side lobe levels
(2)
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2. Circular Polarization with an axial ratio
(Power) of 3x1 or less
3. VSWR of 3:1 or less over the band; over most
of the band, the VSWR is less than 2:1
$ . Balfpov*r beamwidth averages 600 and is praoti-
pally constant over entire band
5. Extremely rugged construction due to conical
shape
6. No external matching transformers required due
to unique oonstructipn.
There are two factors, hovever,,whioh may limit the use
of a conical helix for this band:
1. A maximum package diameter of four (4) feet is desirable
for Band 2.
2. The conical helices built to date have halfpover beam-
vidths which vary between 60 and 700.'
?
Although it looks promising that 900 beamvidths can be
achieved, it is not pertain that both the 900 beamil th criterion
and the four feet maximum diameter restriction.can be met. One
suggestion offered by the Navy 'was that antennas do not necessarily
have to be in the same horizontal plane, thus allowing for the
possibility of a vertical stack of tour helices. This could help
the diameter problem if an antenna interaction problem is not
created by this move.
In the eventuality that the helix does not prove satisfactory
for, Band 2, the results of Band 1 development Oarf he resorted to
and a linearly polarized, small' antenna can be utilized for this
(3)
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_
_1k`1~ih
band, or, a linear slot antenna as suested
k,'s
here.
C. Band b (500 - 1,000 tic
The conical helix has been approved for this band with
the reservation that the 900 beamwidth requirement can
be achieved. As an alternative to the helix in the event
that its beam cannot be broadened, a linear horn Is avail-
able for this band. This horn, as indicated by the Nr_avy,
can also be of the form of a larce wevejuide to coaxial
adapter with a broadband type P`r'obe in the .verzuide.
d. Band 5 (1,000 - 2,200 Me)
Although the Nr vyr has the desicm of a linear horn for
this band, interest was expressed in the conical helix.
A comparison will be made between the helix and the horn
and a decision as to antenna type will be made at a
later date.
e. Bands 5 - 9 2 200 - k,50 0 me, 1, 500 - 10, ()00 r1o ; 10, 000
20,000 lac ; 20,000 - 40, OoQ Me)
For these four bands, the Navy will furnish dra' ings from
which 0 will fabricate finished linearly polarized horns 25X1
for the system. Testing viii be required as a check on
manufacturin7 and also as part of the paeka inf: testin
to insure system operation.
PORT II - CRYSTAL HOLDERS
It is proposed to use crystal holders that will be optimum
for each band of frequencies. In some cases, this will require
some development and special design. We can anticipate achieving a
(4)
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tangential sensitivity greater than 45 dbrt over most of the bands
of frequencies. Some problem-- may occur in Band 9.
a. Bands], 2, and 3 - it is proposed to do some development
on a crystal holder to cover these three bands. It is
planned to use a 1N21B crystal in these bands. No serious
technical difficulties are anticipated.
b. Bands 4 and 5 - it is proposed to use a UG1l9/U crystal
holder and adapter with a 1N21B crystal for each of these
two bands. No development is contemplated and these
crystal holders can be built from standard desici .
are built into the horns per the Navy drawings which will
be sunplidd. Crystal types will be selected which meet
the specifications.
d. Conclusions - no difficulties are anticipated in com-Tleting
the required crystal holders within the time allotted. A
small amount of development work is contem-olated for Bands
1, 2, and 3, but no technical difficulties are anticipated
there. The specifications in Connection with tan nential
sensitivity should be achievable . in all bands with the
exception of Band 9. Further information will be reau.uired
before an accurate prediction can be made of tangential
sensitivity for Band 9. Crystal shutters will be included
in this system.
PART III -
PACKAGING
The packaging of this system has some unknowns in it st present
due to the fact that some of the antennas cannot be specified until
development work has been done. However, the Navy has s_necified
L LL 1
el. J ants b, -(, n, aria y - tine carysLa.t nu.LU(rs Ln (uun uamuz3
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some zeneral considerations which ar6 listed be
1. Bands 1 - 2 Vertically Polarized; Band I Circularly
Polarized (Helix), 450 Polarization (Horn), Vertically
Polarized (Diseone ); Bands 4 - 5 Circularly Polarized;
Bands 6 - 9 #5? Polarization.
2. The system shall mee.t_. specification MIL-E-16#00 Class 2.
The system will be mounted on a mast whose minimum
height is 7 feet and whose maximum height is 17 feet.
4. The maximum desirable base diameter should be 12 feet.
5. The preferred system shape is conical with individual
sections removable and of a conical frustrum shape.
Stacked cylinders were not objected to as an alternative
paokg-ging scheme. The basic thought for the paekaaye
is to keen wind resistance to a minimum.
In view of the above, 0 will approach packaging as early
as possible in the contract because the final package contour
is going to require the 'mouldinm of fibreglass cones or cylinders.
This procedure can be quite time consuming because, since a
large production run is not anticipated, the fibreglass pieces
will have to bA haidmade.
Although the following may bo ehanred considerably after the
final antennas have been decided upon, it is submitted as a
general estimate of what the ,packaging might look like.
Bands 1 and 2
Assuminc that the modified disc ne works over the entire
ran ;e, the bottom stack of the pa.eka;e-could be as shown in the,
following sketch:
i~j
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(6)
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i~v Jr.1U '.mod. Ajr/w Fw~ `
; ~t irns out tit the if abarn~n4~ive.?there are two additional
rrvo`ii. ums - i8 {':I"V StiJ .? Vs . co ... --,c -
h flan be 'olloved
i
a
o a"'!roam ah
iP?f these
Fib lasePactsaut$u*b Ihetf c~,
e
g
Flat, r
firm a fr,,,etrLm of a -amid.
Assuming cndT. purr . uo~y.. -..
This m ga in
Vould look as shove below.
?~t4Y king. of Bend
Qu~.~ . tiA 'o".!Inirical or P"Y"midr.l instead of P oon a eal
a'-
BASE D?4
i0P
AU
SQUATiE\IPD9t5T
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ends4 - 9
These antonnas can either be mounted direct].-y7 to a solid
fibreglass shape, such as a conical frustrum or cylinder, or
might hevo to be mounted to a curved, carbon-filled, honeycomb
fibreglass surface. The reasons for using the special carbon-
filled plate are:
1. Horn antennas operate far better when they are isolated
from other metallie objects. The carbon plates will
prevent reflections from some antennas interfering with
the operation of others.
2. Since the antennas are all low gain, there may be some
back or side radiation present. The carbon plates vijl
absorb this radiation, thus reducing antenna interaction
considerably.
The main problem associated with this phase of the packaging,
and possibly in the lover bands, is that of fabrio&ting the carbon
plate into a curved surface.
One additional Moth* of paok3.ging which will be investigated
consists of a large balloon of thin fibreglass cloth held into
a spherical shape by a small amount of compressed air. This system
has been :need successfull by the Signal Corps and, if acceptable
and practicable, could simultaneously eliminate the radomes for
all antennas and the necessity to camouflage the system.
At this point, the final packaging might take one of four
forms :
1. Conical
2. Stacked Cylinders
3. Pyramidal
Ir-
(8)
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4. Balloon
it the balloon method i- acc~~ .able, the in``,~ - rnal constriction
can by c-.ibical in form which will reduce the comnlexit-- of
fibreglass f orrn'- rea ll.red .
(9)
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PROPOSED BUDGET FOR TP-5500-2.7
CRYSTAL-VIDEO ANTENNAS
2.2.? week: Senior Enr1neer
16.0 weeks Mechanical Engineer
2,160.00
?.1 weeks Development I Engineer
1,950-00
96.4 weeks Machinist
8,676.00
26.0 weeks Technician
2 ,134 .00
11.0 weeks Drafting
q6R. 00
$19,577.20
Overhead 950
18, 598.34
Materials
19, 1614 .00
Travel and Communications
210.00
ShitopinR and Crating
'00.00
$57x099.514
Fixed Fee 7~ I 3,996 g6
TOTAL $61,096.50
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