GRANGER JAMMER

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP67B00511R000100280019-1
• Release Decision: RIPPUB
• Original Classification: S
• Document Page Count: 2
• Document Creation Date: December 22, 2016
• Document Release Date: May 20, 2010
• Sequence Number: 19
• Publication Date: January 2, 1959
• Content Type: MF

_
% oaniuzea ~,opy ~,pprovea Tor rceiease zu i uiuoizu -. ~,ii,-rcurn t rsuuo i i rcuuu i uuzouu i t'- I
MEMORANDUM FOR: Project Director
: Granger Jammer
In my last report of approximately 1 December 1958, I asked for time to
measure the results of three small and simple changes in the Granger box and to
investigate higher powered devices. This-bas been completed. . This paper discusses
the results and makes two alternate recon1dations for our next move.
The changes in thc box produced very significant results. Pilot Githens, a man
with several hundred hours of training in the attack aircraft using the radar for controlled
intercepts was thrown out of lock about once each mile of flight on his first runs. By
maneuvering he was always able to regain lock. This follows since the Jammer stops its
action as soon as lock is broken. A test is now under way wherein the jammer stays on for
a period after break-lock in order to discourage new locks. This break lock occurred up
to about three miles from the target. However, with six hours of experience, he had
improved his skill so that on his one best run, he was not thrown out of lock except outside
eight miles. The slow response of the radar allows for pilot corrections to the effect of the
jammer. After this best run (for the attacker) several more poor uns occurred (i. e. runs
wherein he lost lock regularly (once per mile or more) up to three miles and less. The data
for ranges less than three is insufficient for sound conclusions. More data under three
miles will be taken.
It should be remembered that we have tested this box under the most unfavorable
(most favorable for the attacker) conditions that exist anyplace in the world. The GCI
facility and operational personnel at Mugu are tops. It is their responsibility to test
operationally all U. S. airborne missile systems. In Pilot Githens we have one in a
thousand for pilot skills on a particular airborne missile. But this thought can best be
summed up in pilot Githens own remarks made after four hours of experience at trying to
defeat the Granger box in its last configuration. These remarks are on tape and are
an attachment to this report.
In order to improve the results of the box, more power is needed. of 25X1
Stanfo?r d and I are of the opinion that against the radar in the kind of missile system rep-
resented by Sparrow III (this is the onw we have been testing against) it is not possible to be
sure that any particular and reasonable power will succeed in always breaking locks. The
slow response of the system allows pilot skills and GCI crew skills to enter the picture
in a large way. We believe 1000 watts will do it but can't be sure. 1000 watts would require
100 lb. of equipment. We also believe 50 watts would do it but are less sure. 50 watts
can be built for 50 lbs.
4& It should be remembered that the present Granger box would defeat an attacker
using guns, rockets or beam rider missiles (Sparrow I type). The only known Soviet
airborne missile is judged to be a beam rider type. The present box would probably
defeat a passive or semi-active type missile of the Sidewinder or Sparrow III type, (not
considering the ,ammer's CW effort) but this result against these missiles may be a
function of pilot skill and GCI skill as stated above. This later statement follows from
Sanitized Copy Approved for Release 2010/05/20: CIA-RDP67B00511 R000100280019-1
 Pa Sanitized Copy Approved for Release 2010/05/20: CIA-RDP67BOO51 1 R0001 00280019-1
the errors that are created in the A! radar used for launching so that the missile,
if launching is possible, is not likely to be able to make the necessary homing corrections
? fora hit.
A. Granger box recommendations:
1. That Granger make permanent the-c4 es made in the box on a temporary
basis.
2. That no more changes be made" (o'pt one now under test) unless a better idea
be presented than has yet been heard by the writer. In other words, we freeze
? the design subject to reopening the design only for outstanding ideas.
3. That Phase III and Phase iy checks on the box be run at once under ordinary
conditions as originally plarthed.
i
B. An alternate course of action:
1. Have a 50 watt box built, either Granger Associates or Sanders Associates
could do this with equhi skill. The decision between the companies should
depend on non-technical points; (a) Gr;.r is already familiar with the
problem in detail (b), Granger has personnel cleared and in contact with
Edwards (c) Sanders would bring fresh look into the problems. I tend to favor
Granger since (a) they have more familiarity with our problem and (b) their
close tie with Stanford and Bill Rambo, our consultant.
This plan is expected to take perhaps one year with moderate luck on the tube.
EO watt tubes are less reliable than the one watt tube we are using. Isolation troubles
will increase which might mean no better results at long ranges than we have now.
0
It would appear that the results to be expected from the higher power (50 watt tube)
would not justify the time and effort required for immediate operational needs. An all-
out effort should be made to complete the evaluation and.-assuming that this evaluation is
favorable put the present box into immediate production.
JFS:bp
Distribution:
Copy 1 -
Copy 2 -
Copy 3 -
Copy 4 -
Copy 5 -
P. S. This paper was discussed with Mr. B. on 30 December. He
suggested that the importance justified a joint approach following both
recommendations A and B above with B being done more leisurely and
A being continued at top speed. We also discussed and agreed on a
Project Director further objective - that of making the present box so
that either Granger or Litton tubes can be used, depeQ5X1
on dependability, availability, etc. by a field mod kit
of connectors, etc.
Sanitized Copy Approved for Release 2010/05/20: CIA-RDP67BOO511 R000100280019-1