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Project
Name:
MIREX-3 |
 |
 |
| SSTV
Project Team |
Mirex Board
Dave Larsen N6CO CEO
Miles Mann WF1F Director of Engineering |
Project Managers
Dr. Don Miller, W9NTP, Waldron, Indiana
Farrell Winder, W8ZCF, Cincinnati,
Ohio |
Engineering Staff
Barry Sanderson, Consultant Engineer (no amateur
radio call)
Hank Cantrell, W4HTB, Bowling Green, Kentucky
Boris Garber Russian translator |
Simplicity:
SSTV is a very common mode of image transmutation used HF
and VHF frequencies. SSTV has already been used through
several Amateur Radio satellites, including the Space
Shuttle.
The FM transmission mode, will help reduce interference
and will allow easier Doppler frequency tracking.
| Contents |
|
| 1 |
The
ISS / SSTV Package |
Go! |
| 2 |
Specifications
for Package |
Go! |
| 3 |
Suggested
Transceiver |
Go! |
| 4 |
Video
Operating Mode |
Go! |
| 5 |
Instruction
Plate |
Go! |
| 6 |
Skill
Level |
Go! |
NOTE:
This specification describes a
simple system that can easily be used as a DUAL
PURPOSE System for SENDING as well as RECEIVING
Pictures To and From Russia, for example.
The Transceiver can also serve as a backup VOICE
Channel.
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Details:
1. The ISS / SSTV Package consists of:
A
) TASCO ELECTRONIC CO. PARTS:
a) TSC-70 Color Scanner
b) LCD Display
c) Radio Box MR-70
d) Remote Control WR-70 (requires 2 AAA 1.5v alkaline
batteries)
Items a, b, and c are enclosed within a single box with a
small brush-less "muffin" type fan.
B
) TRANSCEIVER:
a) A Kenwood TM-V7 transceiver is mounted on top
of (A) above to form the complete package.
C
) CAMERA APPLE COMPUTER Product # M5673LL/A
(light weight, small, with provision for
Velcro mounting on Spacecraft Window or inside
spacecraft).
a) Camera power cord & Video cable consist of
coiled cables (similar to telephone handset cable).
Maximum extension 15 feet.
 Top
2. Specifications for Package (A, B &
C per above)
Electrical:
1. Power Block -- All wiring within
package is terminated on a Power Block on rear of
package.
2. Power Input: +12v, +1.8/-0v
@ ____ amps max.
3. All current carrying wires within the package
are fused with P/N______(Russian) fuses.
4. Each primary power lead to Package is fused
with P/N ______ Russian fuses.
RED lead is +12v, BLACK lead is Ground.
5. Transceiver Output has a 2 foot length of
Coaxial Cable terminated in an SO 239 Connector.
6. Video Output is NTSC.
Mechanical:
1. Weight of Tasco Parts (per A above)
including muffin fan _____kg.
2. Size of Tasco package including a, b, c above
-- within a box 6x6x6 inches.
3. Transceiver (per B above) ________kg.
Environmental:
1. Humidity: 98% RH without
condensation.
2. Temperature operating: 0 degrees to +50
degrees C.
3. Acceleration: All above parts to withstand 8
g's.
Top
3. Suggested
Transceiver:
| Kenwood
TM-V7 |
| Frequency Range |
144
Mhz: |
TX:
144 - 148 Mhz
RX: 118 - 174 Mhz |
| 440 Mhz: |
TX: 430 - 450 Mhz
RX: 410 - 470 Mhz |
| Mode |
F3E (FM), A3E (AM) (VHF Main band Rx
only) |
| Power
Requirement |
13.8 V DC +/- 15 %, negative ground |
Current Drain (High Power)
Transmit |
144 Mhz: Less than 11 A
440 Mhz: Less than 10 A |
| Receive |
144/440 Mhz: Less than 1 A |
| Operating
Temperature |
-4 deg F ~ +142 deg F (-20 deg C ~
+60 deg C) |
| Antenna
Impedance |
50 Ohms |
| Microphone
Impedance |
600 Ohms |
| Frequency
Tolerance |
+/- 3 ppm (14 degF - 122 degF) |
| Weight |
1.2 kg |
| Dimensions,
projections not included (W x H x D) |
5-1/2 x 1-9/16 x 7-7/16 ins |
| |
|
| TRANMITTER |
| RF
Output Power |
HI
Mid (approx)
Low (approx) |
144 Mhz: 50W, 440
Mhz: 35W
10 W
5W |
| Modulation |
Reactance
Modulation |
| Maximum Frequency
Deviation |
Less
than +/- 5 kHz |
| Spurious
Radiation |
Less
than -60 db |
| Modulation
Distortion |
Less
than 3% (300-3000 kHz) |
| |
|
|
| RECEIVER |
| Circuitry |
Double
Conversion Superhetrodyne |
| Intermediate Frequency |
1st IF |
144 Mhz: 38.85
Mhz
440 Mhz: 45.05 Mhz |
| 2nd IF |
144 Mhz: 450 Khz
440 Mhz: 455 Khz |
| Sensitivity
(12db SINAD) |
144
Mhz: Less than 0.16 uV
440 Mhz: Less than 0.16 uV |
| Sensitivity |
-6 db
More than 12 kHz
-60db Less than 28 kHz |
| Squelch
Sensitivity |
144
Mhz: Less than 0.1 uV
440 Mhz: Less than 0.1 uV |
| Audio Output
Power |
More
than 2 W (8Ohms, 5% distortion) |
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4. Video Operating Mode
a)
Picture is "grabbed" from camera by pressing
"ACQ" button on Tasco WR-70 Remote Control
Unit.
b) The PRIMARY Operating Mode of this
System is Robot 36. After acquiring a picture, as will be
noted on the LCD Screen, press "36", as noted
under MODE. The TX button is then pressed.
This provides for a repeating cycle of 2 Robot 36
pictures which has a timing of 36 seconds on the 1st
picture, a 20 second interval, then another (repeated) 36
second picture.
c) Picture will repeat per (b) above
until a new picture is acquired.
d) Interval between pictures may be
changed manually by turning system OFF then back to ON as
desired.
e) Picture transmission may be deleted
at any time by turning System OFF or by pressing the RX
button on the remote unit.
Top
5. Instruction Plate
Operating Instructions in both Russian and English will
be attached under a "see through" cover to the
outside of the package.
Top
6. Skill Level
This project has
been designed for the more advanced users who can afford
the additional expense of receiving a 70cm signal. The
SSTV format chosen, is one of the simplest formats to be
decoded. We expect a large number of stations to be
tuning in to the down link channel to decode the
continuos feed of Still images.
The frequency and Band have not been chosen at this
time. The Mirex-SSTV system can operate on any ITU
Satellite frequency in the 2-meter and 70-centemeter
bands.
Top
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Mirex ISS
