INFLATABLE PARABOLIC ANTENNAS

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78-03424A002000080078-8
• Release Decision: RIPPUB
• Original Classification: S
• Document Page Count: 3
• Document Creation Date: December 22, 2016
• Document Release Date: September 19, 2011
• Sequence Number: 78
• Publication Date: February 25, 1958
• Content Type: MEMO

Sanitized Copy Approved for Release 2011/09/19: CIA-RDP78-03424AO02000080078-8
Office M emorandu IIETfM.. STATES GOVERNMENT
RA1 A_SSS
Chief, Engineering Division, OC
FROM : Chief, Supplemental Programs Division, OC
SUBJscr: Inflatable Parabolic Antennas
REFERENCE: ENG 8-102
DATE: 25 February 1958
I- PA+%m^n the sources of inflatable parabolic antennas;
we find both systems possessing the
properties req re or heir intended use. Since a representative
of the EAB was present during the 0 contact, we have firmly
established our needs for a set of five antennas. We, therefore,
have budgetted funds under Allotment No. 8-7912-50-600 for the
purchase of these antennas.
2. The following constitutes the firm design requirements
for these five complete antennas:
A. Breakdown and packaging for transportation in
containers not to exceed 20" X 20" X 12" outside dimensions.
B. Receiving only from 10,000 mcs down to 700 or
800 mcs. (The lower limit will be determined as that
frequency where the in of the parabolic equals a con- 7
ventional array.) C7o r AL.,,
k ` v-6 ea e4
C. Minimum number of feed horns still maintaining a
VSWR of better than 3 to 1.
D. Fifty ohms unbalanced feed using high quality
coaxial cable for minimum loss.
E. The maximum operating spate to accomodate the
reflector, feeds, and blower will be seven feet high, nine
feet wide, by nine feet deep.
F. The blower for inflating the antenna must be
electrically free of interference and audibly quiet outside
the room of operation.
G. Ninety degree manual rotation of the feeds must
be provided for polarization changes.
H. Side lobe response should be at least 10 db. below
the main lobe.
CONFIDEUTIAL
f. The/blower
Sanitized Copy Approved for Release 2011/09/19: CIA-RDP78-03424AO02000080078-8
 Sanitized Copy Approved for Release 2011/09/19: CIA-RDP78-03424AO02000080078-8
25 February 1958 - 2 -
sPM 8-555
I. The blower motor should be capable of operating
from 110/220 volts 5060 cycle sources as well as 12 volts
d.c. (If a complete motor change for direct current oper-
ation is required, we request that we be advised for
determining the quantity desired.)
J. Both companies to our knowledge indicated the
capability of attaching a simple and inexpensive azimuth
indicator to the reflectors. This should be established
as a firm requirement.
K. The following table of beam patterns and in are
established as a guide but the maximum in is requested
except at 10,000 mcs where the beam width must not be smaller
than two degrees.
FREQ. MCS
GAIN BE
AM WIDTH
800
22 db
13?
1860
28 db
6.50
4320
34 db
3.1?
10000
36 db
2.50
L. In the case of the proposal, two radomes
for outdoor installations are requested with their necessary
blowers, guys, and base plates. (These blowers should also
operate from 110/220 volts at 5060 cycles and 12 volts direct
current.) The 0 antennas should be requested with two
tower mounts for outdoor use since we understand their antennas
are weather-proof.
M. The main criteria for these antennas is maximum in,
highly flexible for installation, and packagable in 20X20X12
inch containers.
3. We request your recommendations as to which company should
be contracted since we are anxious to commence work on this equipment.
4. As an added comment on establishing a contract, we request
that all R&D work required should be priced against the first antenna
with four additional units as a basic construction order.
Cv 8""N F. aD ENS T IAL Acting
Distribution:
Orig & 1 - Addressee
Sanitized Copy Approved for Release 2011/09/19: CIA-RDP78-03424AO02000080078-8
 Sanitized Copy Approved for Release 2011/09/19: CIA-RDP78-03424AO02000080078-8
El UNCLASSIFIED ^ INTERNAL ^ CO' . fNTIAL
iE ONLY
ROUTING AND RECORD SHEET n CMTI A
nn N cI I
SU$JECT: (Optional)
FROM: OC-SP/EA
NO. sww 8-555
DATE
TO, (Officer designation, room number, and
buildin
)
DATE
OFFKER'S
COMMENTS (Number each comment to show from whom
g
IIEGEIVED
FORWARDED
INITIALS
to whom. Draw a line across column after each comment.)
1. SP/,
For approval, pie.
2. SPD
s.
1br simature, pi
3. OC-E
6.
Irv C Q dt:~ t-c
7.
G`' P
8.
~roc~?~~e J _ ?
JJ..
10.
11.
12.
13.
14.
15.
56 610 Eo"'EN1O1~ CONFIDENTI L ^ USE ONLY ^ UNCLASSIFIED
Sanitized Copy Approved for Release 2011/09/19: CIA-RDP78-03424AO02000080078-8