User's Manual

Pacific Microwave Research, Inc.
AT-100C3 User’s Manual
© 2003
2
2.1.1 DC Power Input
The AT-100C3 is designed to operate from a nominal +12 Vdc power source. Power is
supplied through the front panel DB-9M connector (J3) with +12 Vdc on Pin 5 and
Ground on Pin 9. This source should be fused at 2.0 A. The AT-100C3 will operate over
a voltage range of +11 to +14.5 Vdc. Power consumption at the high power setting (2 W)
is nominally 1.2 A. Power consumption at the low power setting (0.5 W) is nominally
0.7 A. The input to the AT-100C3 is internally protected against reverse polarity. The
AT-100C3 transmitter is operating whenever power is applied.
2.1.2 Antenna
The antenna is connected to front panel female SMA connector (J9). Any resonant
antenna is suitable for connection. Antenna type and gain should be determined based
upon the intended application. Only high quality coaxial cable should be used to
interconnect the transmitter and antenna. All SMA connectors should be tightened with
the appropriate 5/16” wrench using approximately 5 in./lbs of torque. MAXIMUM
TORQUE IS 8 IN./LBS. DO NOT OVERTIGHTEN. Thumb tight connections are not
suitable for reliable operation!
2.1.3 Video Input
Video is input to the AT-100C3 through the front panel BNC connector (J10). This
unbalanced input accepts a nominal 1 Vp/p video input. The transmitter may be factory
configured for the NTSC or PAL standard. An NTSC transmitter must be used with an
NTSC receiver. A PAL transmitter must be used with a PAL receiver. Maintenance of
proper video levels is important to prevent over-modulation of the transmitter. High
video levels could potentially cause interference to adjacent channel users. Low video
levels will result in a lack of luminance at the receiver. Proper link performance demands
attention to video levels.
2.1.4 Audio Input
Audio is input to the AT-100C3 through the front panel DB-9M connector (J3).
Typically, the AT-100 is configured for two audio subcarrier channels. Each audio
subcarrier has a balanced input with a nominal impedance of 600 Ω. The AT-100C3 may
be factory configured for line or microphone level inputs. Line level audio is typically 0
dBm and microphone level is typically –50 dBm. Full deviation (+
75 kHz) on a
transmitter configured for line level input is represented by a signal input level of + 9
dBm at 400 Hz. The input for subcarrier number one is on Pin 2 (+) and Pin 7 (-). The
input for subcarrier number two is on Pin 3 (+) and Pin 8 (-). Unbalanced audio may be
connected to the subcarrier inputs by connecting the high side of the audio source to the
(+) terminals and leaving the (-) terminals unconnected.