TRIP REPORT- RT-21 TRANSMITTER

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78-03424A000800010042-8
• Release Decision: RIPPUB
• Original Classification: S
• Document Page Count: 3
• Document Creation Date: December 22, 2016
• Document Release Date: February 8, 2012
• Sequence Number: 42
• Publication Date: December 30, 1959
• Content Type: MEMO

Declassified in Part - Sanitized Copy Approved for Release 2012/02/08: CIA-RDP78-03424A000800010042-8
~~. VVI' L) L11 I IfL
Office Memorandum ? UNITED STATES GOVERNMENT
? The Files - RD-107, Task Order 10
Trip Report - IT-21 Transmitter
to monitor progress made in developing
the RT-21 transmitter. Persons present for discussions were:
DATE: 30 December 1959
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1. On 10 December 1 ? a visit was made to
2. All sections of the RT-21 transmitter have been completely
breadboarded and tested and all that now remains is the integration
of these sections, plus construction. stated that the
RT-21 transmitter will use two each Z11337 transistors in parallel
as a final amplifier stage and will be capable of delivering 2 watts
of RF power into the matching network. To protect the final amplifier
transistors from burning out while antenna tuning and matching is
underway, the bias of these transistors will be controlled such that
the input driving power will be limited during tuning by the action of
a voltage control network.
3. Antenna Hatching Network - The total time required for the
antenna matching network to be first repositioned and then tuned for
proper operation will be approximately 3 minutes. This time cannot
be shortened because of the manner and direction of physically tuning
the inductance of the matching network. Pre-positioning causes the
inductance to move to one end of the coil, and tuning tunes in the
opposite direction along the coil until a tune state exists; the higher
the frequency the longer the tuning required. If this time is decreased
by increasing the speed of rotation of the inductance and capacitor
mechanical oscillations in tuning will occur near the resonate point.
This is caused from the capacitor over-shoot in tuning.
4.,_~ring the pre-position phase of tuning of the matching
network was told to be sure that no RF radiations would be allowed.
During the actual tuning phase.. RF will be radiated from the antenna
since the phase and magnitude detecting circuits require a sample of
the PF signal to effect proper tuning.
Declassified in Part - Sanitized Copy Approved for Release 2012/02/08: CIA-RDP78-03424A000800010042-8
 Declassified in Part - Sanitized Copy Approved for Release 2012/02/08: CIA-RDP78-03424A000800010042-8
SUBJECT: Trip Report - RT-21 Transmitter
5. The RT-21 consists of the following stages with the number
of transistors numerated for each stage as follows:
Oscillator and Sweep Circuit
Driving Circuit
Output Amplifier Stage
Phase and Magnitude Sensing Circuits
Voltage Control Circuit
400 Cycle Power Supply
Servo Amplifier
Voltage Regulator
DC-to-DC Converter
4 transistors
1 transistor
2 transistors
4 transistors
3 transistors
2 transistors
4 transistors
2 transistors
3 transistors
6. Every attempt is being made to minimize the number of controls
that will require manipulation by the operator. At present all the
operator need do to place the RT-21 into operation is connect the power
supply and antenna, change the bandswitch, and install the crystal
into its holder. The pre-positioned control may be undertaken auto-
matically through a switch located directly underneath the crystal
holder and actuated by the insertion of the crystal. This switch may
also be used to prevent RF from being radiated during pre-positioning.
Another possible means of providing a pre-positioning action may be
through the connection of the power cord to the transmitter. This is
as yet not firmed up and is now being considered by
to insure that nothing is overlooked.
7. The next thing discussed was the receive/transmit function
that is to be incorporated in this transmitter, and the type of key
that will be enclosed. The writer stated that this y had a
miniature key, and if available would be supplied to Further,
that a miniature receive/transmit relay might also be available.
8. stated that the RT-21 would be ready for delivery 25X1
approximately the middle of April 1960. He was informed by the writer
that the contract expired in February 1960 and that it was believed
that the transmitter would have been ready by that time. Because of
the trouble encountered in the mechanical oscillations of the antenna
matching network, the contractor has lost considerable time. Previous
to this trouble the work on the RT-21 was approximately 12 months ahead
of schedule. Further, 0 stated that his section was not
authorized to begin the RT-21 program until 8 September 1958. This
delay was due to problems arising with regards to the type of reports to
be submitted under this contract, and approximately two months were taken
to clarify the situation. Originally, the cont-rnnt is d 15 June,
1958 and was to run for a period of 20 months. section
Declassified in Part - Sanitized Copy Approved for Release 2012/02/08: CIA-RDP78-03424A000800010042-8
 Declassified in Part - Sanitized Copy Approved for Release 2012/02/08: CIA-RDP78-03424A000800010042-8
SUBJECT: Trip Report - RT-21 Transmitter
received their rk order on 8 September 1958 and the contract was
considered to run for a period of 20 months from that d te, which
makes the ending date around 15 April 1960. was requested 25X1
to submit a request for additional time to cover that period of delay.
Distribution:
1i+ subject File
R+D Lab
OC-T
i1onthly (2)
EP Chrono
Declassified in Part - Sanitized Copy Approved for Release 2012/02/08: CIA-RDP78-03424A000800010042-8