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Place the transmitter on a flat surface with no other objects within 2 inches. This is important for convection
cooling and running for periods of more than 10 minutes continuous key down.
Connect the red lead from the DC power jack to a good regulated 12 to 14 Vdc >1A power supply or battery
directly and the black lead to negative or ground. Longer leads or junction boxes with other gear could put noise
in the picture.
Connect a good low VSWR 33cm Antenna using low loss 50 Ohm coax to the antenna jack. Best not to use
adaptors, but strictly N plugs with 420 MHz and above.to minimize losses. If you have a RF power meter that is
rated for 33cm, you can put it in the antenna coax line for the initial VSWR and system tests.
Select the local ATV frequency from the 5 available on the front panel channel switch. Make contact with a close
by ATVer on the 2 meter coordination and talk back frequency to make sure the frequency or repeater is clear and
have some one to comment on your tests. Watching yourself on another TV in the shack can give false results
from overload or multipath.
Flip the Power switch to on and the green LED will light if you connected to the power supply correctly. Flip the
XMIT/REC switch to XMIT and the green will go off (as well as the downconverter if connected) and the red LED
and RF output will come on in 2-3 seconds. If driving an amplifier, verify that there is less than 10% reflected
power within 15 seconds before further operation. If all is OK, do the linear amplifier ATV set up procedure. after
that, you can plug in the camera video, line and or mic audio. Set the Mic and/or Line Audio gain as you speak
normally at normal distance up to the point that the red LED winks off, then slightly back down. When the XMIT
switch is on, you are still transmitting when the red LED winks off during audio over deviation peaks. Have the
local ATVer talk your antenna rotation in for best picture via two meter voice.
Please read the detailed information on each connector and control that follows in this manual.
REAR PANEL:
POWER INPUT JACK. A 4 pin plug 2 ft cable is provided for
connection to your source of +12 to14 Vdc and to a
downconverter. Currant draw is <2A in transmit. Pin 1 is DC
ground and a black wire. Pin 2 is + and red. A cable with a
coaxial plug on the end connects to pins 3 (-) and 4 (+) to
output to a downconverter in receive. Power coaxial plug is
center +. The TX33-.1s works best from a well regulated
voltage source with leads no longer than necessary. The
transmitter is set up by us from a regulated 13.8 Vdc supply.
Do not exceed 15 Vdc input. In case the voltage is reversed,
there is a internal series diode to prevent damage to the
unit. 16 v zeners on the sound and T/R relay boards should
blow the internal 1A fuse if this voltage is exceeded.
Any ripple or noise on the DC line may be seen in the
transmitted video. For this reason, if a single large power
supply is used to power this and other equipment, all leads
must connect directly at the power supply terminals, not to
an external terminal block. If an external amp is added, it is
best to run it from its own separate power supply.
TX33-.1s ATV Transmitter Quick Start
DOWNCONVERTER POWER. A 2 ft cable is supplied with
a 2.1 X 5.5 mm plug on the end to connect from this jack to
a TVC downconverter. DC power (center is +) is at this jack
when the XMIT / REC switch is in REC and open when in
XMIT.
2 AMP FUSE INSIDE. The TX33-.1s itself draws less than.5
amp in transmit, and .1 amp plus external downconverter in
receive - A 1.0 amp 3AG fuse should handle both.
EXT KEY JACK. Grounding the tip keys the transmitter.
This jack is in parallel with the front panel transmit/receive
(XMIT/REC) toggle switch and can be used to key the
transmitter from an external switch to ground or key an
amplifier as long as the amp is run from a 13.8V power supply.
50 OHM 33 CM ANTENNA. A UG21 type N plug is provided
to attatch to low loss .5" size 50
are very high in transmission lines.
foam filled types such as Belden 8214, or semi rigid Belden
9913 or Times LMR400. Put the connector together properly,
or buy a ready made cable. The type N connector has good
moisture resistance and low loss at UHF but use two layers
of vinyl tape or Coax Seal on all outside connections to
prevent moisture contamination. The antenna and feed line
are the most important part of your ATV system, and therefore
the last item to just try and get by with.
2
coax. Losses at 33 CM
We suggest using the
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