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1994-11-27
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Page 1
TECATV Version 1. 3 3/1/92
Subject: AMATEUR RADIO TELEVISION
[Category: Tec]
ATV _ Amateur Radio Television-
A proper demonstration of airborne Amateur Radio Television (ATV)
requires several factors coming together precisely at the chosen
time and place. They are: 1. Good weather for flying and steady
camera transmissions. 2. Good visibility and adequate light. 3.
Competent camera operator. (No aimless panning.) 4. Camera
operator capable of describing what he is shooting. 5. Being on
target at precisely the right time for those watching the
demonstration.
Murphy's Law says that if something can go wrong, it will. There
are marvelous opportunities in "live" ATV demonstrations for
Murphy to step in and show his stuff. Here are a few examples I
have seen: 1. Rain, snow, windstorm or other hostile weather
problem. 2. ATV crew can't find targets of interest to those
watching the demo. 3. The receiving antenna is set up on the
wrong side of the building to "see" the ATV aircraft. 4. Some of
the government officials and hams scheduled to see the demo don't
show up. 5. Some key viewer shows up minutes too late to see the
demo. 6. The ATV crew, either in the aircraft or at the receiver
site, discovers they forgot a crucial connector, cable, or piece
of equipment. 7. The camera operator is untrained in how to shoot
and pans dizzily, leaving viewers unimpressed and woozy. 8.
Battery goes dead.
These problems may be overcome by a few simple steps: 1.
Prerecord aerial ATV demos. Pick your clear weather day and
record a "perfect" 5 minutes long video. Anything longer may bore
the viewers.
(a) The video should always be shot in the area of interest to
those for whom the demo is being made. Select known landmarks and
points of interest. These might include the courthouse, freeway
through town, a fair or other outdoor event, lake or reservoir
activity, hospital, city hall, or any other location that viewers
can readily identify. Always ask the agency for whom you are
going to demonstrate if there are any particular points of
interest they want to see.
(b) Look for unplanned targets of opportunity. These can often be
some of the best material to demonstrate ATV. Targets of
opportunity could be a traffic accident scene, a fire, racetrack
action, any outdoor crowd, downed aircraft (not yours!),
etcetera. 2. Proper camera technique. DO NOT PAN. We must
remember that the majority of viewers are unfamiliar with seeing
things from a few hundred feet up in the air -- and in motion.
Hollywood uses a device (Steady-Cam) to keep their aerial shots
rock solid -- no jitter, jump, bump and vibration. Since they
cost more than some airplanes we use, the basic rule that bears
repeating is: DON'T PAN. DON'T ZOOM. That leaves two basic
techniques for ATV:
(a) Level, straight line flight. The camera picture travels at
the same ground speed of the aircraft. The camera operator can
announce where he is and in what direction he is traveling. Help
the viewer to locate where you are. If the viewer cannot identify
with what is on the screen, ATV serves no purpose. The sooner the
viewer knows where he or she is in respect to the picture, the
better is your work. It helps when the pilot can make all turns
in one direction. If all turns are left-hand turns, all camera
shots can be out the left side and vice versa. In this manner the
picture never leaves the ground. In other words no shots of sky,
camera gyrations, shots of your feet, the back of the pilot's
head, etc. If you are only recording and not transmitting live,
shut off the camera when you don't want to record and transmit
junk. A good camera operator can literally edit on the spot.
(b) Orbiting the target. The aircraft does 360's over the target
or a helicopter hovers or does slow flight 360's.
When the ATV transmitter, whether airborne or on the ground, is
too far from the receiver to adequately provide a high quality
picture, either (a) don't show it or (b) videotape it in the
field and retransmit it later when you have a Circuit Merit 5
path. The ATV aircraft may be down in a canyon, for example,
taping an incident. It is out of range of the receiver for a CM5
path. After recording what it wants to transmit back to the EOC
or IC (Incident Command), the plane can climb to an altitude
sufficient to assure the reception of a CM5 playback
transmission.
Aerial ATV platforms I have seen or used have included slow
flying fixed wing aircraft owned and operated by the RACES
personnel, Highway Patrol helicopters, Civil Air Patrol aircraft,
and county fire and police helicopters. Needless to say, fixed
wing aircraft must be of the high wing variety.
Because of Murphy's Law and daylight limitations, it is now
standard operating procedure for the State RACES ATV unit to
prerecord ATV demonstrations. In this manner the crew can pick
ideal flying and lighting conditions. Targets with which the
viewers can relate are determined in advance. When the day (or
night) of the presentation arrives, a proper video demonstration
can be made to the local government officials regardless of how
hard the wind is blowing outside, the downpour or snowstorm in
progress. The officials aren't interested in the aircraft
installation, hardware, wiring, cameras, radios and so forth.
They are interested only in results. Good results. They are used
to seeing helicopter news video. ATV results can be close in
quality with the right equipment and skilled operators. If it
isn't or it's still in the gee whiz hobby stage -- don't
demonstrate it. More harm can be done by failures. The memory of
them is long lasting. -KH6GBX RB 105-109
"RF-1" MICROWAVE VAN TAKES RACES "ABOVE THE CROWD"
Imagine a RACES communications van that can deliver 24
simultaneous voice or data circuits plus full duplex Amateur
Television ("ATV") videoconferencing. Now add High Frequency, VHF
and UHF radios -- both Amateur and Public Safety, a thirty foot
pneumatic mast, on-board power generator, and four wheel drive!
"Wonderful," you say? California State Office of Emergency
Services Region 2 RACES calls it "RF-1".
In service since September 1990, RF-1 is the product of nearly a
year's development by OES Region Two's Special Communications
Assistance Team (SCAT) and the RACES.
RF-1 Project Coordinator Steve Cembura (N6GVI) led the team of
Amateurs who designed and built the mobile 5.8 gigaHertz
microwave system. This full-duplex link operates in both analog
(video) and digital (T-carrier) modes. The system includes T-1
channel banks which combine up to 24 separate voice or data
circuits on a single microwave signal.
SCAT Public Safety Radio Officer Dick Epting located the vehicle,
a surplus Electronic News Gathering unit from San Francisco's
television station KGO, and installed two-way radios and
emergency equipment. Another San Francisco broadcaster, KPIX-TV,
donated a broadcast quality color TV camera and other necessary
video and audio gear.
RF-1 got its first field trial providing video and two-way radio
communications for a major earthquake preparedness exercise in
Solano County. It was displayed at the last Emergency Response
Institute in San Ramon and at the opening of the new State OES
Media Center in Sacramento. RF-1 is now Region Two's "first in"
mobile communications resource for earthquakes and other
disasters.
"RF-1 is more than just a comm van," says Region 2 RACES
Coordinator Art Botterell. "All the technology wouldn't mean a
thing without skilled operators. The RF-1 team put themselves on-
call day and night to offer this unique public service." RB159
ATV ANTENNA ON AIRCRAFT
The antenna should be mounted half-way between the tail and the
rear window, on the bottom of the fuselage, to minimize "shadows"
in banks and turns. Select a whip antenna similar to that used
for transponders and DME except that the whip will have to
resonate at 434 Megahertz. An aircraft-type antenna made for
aluminum skinned aircraft. It must have a coaxial fitting at the
feedthrough base of the antenna and not the type that has a lug
mount. Cut the radiator (whip) to seven (7") inches. Run the
coaxial transmission line to the back seat with a BNC male
termination. RB 86-31