Dear Friend.
Thanks a lot for the helpful information.
I have inspected my VCR and it has an Audio-Video (A/V) IN and A/V
OUT. It also has an RF IN and RF OUT. Is S-video different from these
two? What is the Standard video?
S-Video is a different connector - more like the PC keyboard and mouse
connectors. You will use the standard video connectors because they are all you
have.
Also, transmitters come in many ranges from 500 Mhz upto 2.4 GHz and
also 10 and 24 GHz for FMTV. Can you advise which one I should buy?
Get a transmitter/receiver combination that offers the range you need. Be aware
that the advertised range is typically for unobstructed line of sight. The
range under "real world" conditions will be less. Consider the advertised range
on wireless PC networking (wi-fi, 802.11 at 2.4GHz). It's something like 300
meters outdoors, 50 meters indoors. In the real world, it's also dependent on
the antennas used and any sources of interference. With the wireless baby
monitor on at our house, a laptop wireless card can't sync with the router from
8 meters away on the same floor. A friend has a three level house with the
wireless router in the basement and desktop PC's with wireless network cards
(which have external antennas) on each the other floors. The maximum distance
is about 20 meters and the PC's work OK.
I cannot install visible directional antennas on my transmitter or
reciever, especially my transmitter because I would be wearing the
camera on my body and I may change position at times. For a range of
300 meters, can I do away with my transmitter antenna?
No. Note that your are at the distant end of the range of most non-licensed
transmitters.
Moreover, for
penetration thru walls and out of line-of-sight, do I have have to use
a higher frequency transmitter?
Frequency is not a major issue. Unlicensed transmitters are power limited based
on the frequency used and most will provide similar range whether 2.4GHz or
10GHz.
Assuming that the transmitter you choose has provisions for an external antenna
(not all do) you may be able to increase the range. Get a metal hat
(construction hard hat) and mount a vertical antenna (non-directional, but
definitely visible) on it to get the antenna above most of the obstructions and
provide a ground plane for the antenna. To further increase the range, get a
relatively wide beamwidth antenna for the receiver (for 2.4GHz, something like
the Mini-Tenna at
http://www.etherdesigns.com/pages/3/index.htm). Point the
receiving antenna at the area to be covered and check the coverage by walking
around with your camera/transmitter to determine the best aiming of the receiver
antenna.
If the above doesn't give you enough range, you may be looking for a more
powerful (licensed) transmitter. Depending on your country, there may or may
not be reasonably priced commercial equipment available. If your application is
personal (non-commercial), you might consider getting an amateur radio license -
hams can run much more powerful transmitters. Remember that there are penalties
for a higher power transmitter - it costs more, weighs more, and needs bigger
(and heavier) batteries.
Antennas are a visible solution to increasing range, but they require no power
and add very little weight, compared to a more powerful transmitter and it's
associated batteries.
Consider the relative range of 2.4GHz wi-fi in different settings:
http://www.weca.net/OpenSection/range.asp?TID=2
I'm using wireless networking as a reference because both wi-fi and video are
high speed, wide band signals and there is published information about wi-fi.
I have a Sony Trinitron TV. I also have a 17" monitor with my computer
which has a TV Card. The camera I am considering has 570 lines of
horizontal resolution. Speaking in layman (me) terms, can I expect the
video quality of the programs and movies we generally watch on TV in
our daily lives?
Your should have adequate resolution. However, be sure that you can return the
camera and the transmitter/receiver for refund if they don't perform as
advertised.
Thanks again for the help.
Best Regards,
Your application sounds like a convention floor interview project (or a school
reunion), with the wearable camera and 6 hour battery requirements. In a
situation like this, the ideal placement for the receiver would be the top
center of the area, with cable to the VCR and TV.
*** You can't put the camera in your shirt pocket and the transmitter in your
trouser pocket and get 300 meters range.***
You might get 10 meters if you're turned so the transmitter antenna is exactly
aligned with the receiver antenna, but you may only get 3 meters.
The criteria for distance when using RF are antenna height, antenna gain, and
transmitter power. There are no shortcuts and no easy answers.
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