As we realize
many of our customer may be confuse over wireless system application
we have compile some FAQ for your reading. Hope you will find this information
WIRELESS TRANSMITTER &
Q1: What do you mean "line of
sight" and the range I can expect?
A1: "Line of sight" in
wireless equipment simply mean the transmitter and receiver is install
on a 100% flat plane with zero obstacle and zero
interference (Electrical, Radio, Electromagnetic and even Atmospheric
interference). Both antennas must be at the same height (at least 5
ft. and preferably MUCH higher due to the nature of radio
transmission) and situated identically along the same horizontal or
vertical plane. The "approximated range", whether realistic
or exaggerated- as found on many websites- is always measure based on
maximum line of sight conditions. When using wireless system customer
must expect some degree of interference and realized that they are not
100% even our million dollars mobile network sometime do affect by
interference. No doubt wireless system is easy to install and the
quality is quite good they cannot match the quality of
wired system. Most wireless sold by us has been hand
selected and tested by us for practical use and the quality is of the
best you can obtain in the market, however you must not expect
wireless equipment to penetrate multiple wall, partition, metallic
screen. Structural beam etc. As such invest in the very best and most
powerful equipment money can buy of course IDA and government approval
is very important so as not to break the law. You can be assured that
when we sell wireless we sell the best equipment and the cost is also
very reasonable. If you search other site you can come across our
system selling at much higher price.
Q2: Can I use 433/
434 / 900 MHz in Singapore. What about 2.4 GHz units?
A2: 900 MHz wireless system MUST not be use
as they are not approve for use in Singapore. Some 433 / 434 MHz and
2.4GHz can be used in Singapore but the safest is to invest one that
is IDA approved (look out for IDA approval logo on the set) The
above frequencies are part of the radio spectrum. As far
as 2.4 ghz (or 2,400 megahertz) signals in motion- it's a little hard
to explain. When both points are stationary, you'll generally have a
crystal clear signal (depending, of course- on interference and
barriers). As one or both of the points are in motion, there will be
digital interference. Unlike "snow" received from lower
frequency units, you get momentary pops in between clear signals.
Higher frequency signals are more directional by nature. By using the
two receivers (one with built in omni directional antenna & the
other with a high gain directional antenna), some normal interference
will be stabilized. Essentially, 900 megahertz is better for those
applications where motion exists in one or both links (i.e. body worn
or mobile applications). 2.4 gig systems penetrate walls 10-20% more
efficiently than 900 systems. The quality is otherwise identical. The
TX-5 and TX-5A (434 MHz UHF) are both excellent transmitters- but 434
MHz can be a little tricky in the "real world". The
receiver/ antenna combinations used will make all the difference in
terms of the signal quality and range. Performance will range from
marginal or even poor to excellent, depending on the quality/
sensitivity of the tuner and the dB gain of the antenna within the UHF
band. A lot of consumer video equipment is known for having relatively
weak built-in UHF tuners. For that reason, most would-be users of UHF
434 are ideally recommended to use either 900 MHz or 2.4 ghz
transmitter and matched receiver. Again, however, lower frequency
(900) units will provide a MUCH more stable signal than microwave
links for transmitters and/ or receivers in motion. For stationary
links, 2.4 giga hertz is usually ideal due to it's slightly higher
penetration ability- but all will have similar excellent performance.
Q3: Are SecureCiti
wireless transmitters more powerful or better than others I've seen
A3: Well, right off the bat- there are
several considerations to make regarding this topic. When it comes to
most transmitters we've seen out there on the net-profit over
performance value seems to be the primary consideration of most
sellers. Not to be confused with most toys with their low power output
and often heavily exaggerated claims of range / distance ability, our
A/V systems have the latest built in surface mount technology. Our
2.4Ghz systems use FM synthesized signals, featuring more stability
and higher resolution capabilities than the typically found AM
modulated units. Crystal IC controlled transmitters with phase loop
lock receiver for drift-free signal performance. Patented signal
reception technology and exclusive internal omni directional antennas
in our 2.4 Ghz equipment make our units head and shoulders above
inferior and highly directional units which feature adjustable flat
plate antennas requiring both antennas to be directly pointed at each
Q4: What interference
sources and barriers are the best & worst?
A4: When it comes to wireless, there really
is no such thing as a 'good' barrier or interference source- but there
are definitely some that are much worse than others. If you are using
a 900 megahertz cordless phone around 900 MHz wireless video, you may
experience interference. Likewise, 2.4 GHz video and telephone
equipment competing for the same bandwidth may cause undesired
interference as well when using 2.4 ghz equipment. If you use channel
one of the 900mhz transmitter, interference may result. However, if
you use channels 2/ 3/ 4, cordless phones will not interfere. *NOTE:
when you operate this transmitter on channels 2, 3, or 4- an amateur
radio license is required to use legally. SecureCiti International and
Securitex Electronic Systems Engineering assumes no liability for
unlawful use of these items.
Q5: What is a "high gain
antenna" and how effective are they?
A5: A high gain antenna is a specially
engineered antenna which is 'tuned' to a particular frequency range
within a given bandwidth of the RF (radio frequency) spectrum. They
are extremely effective when used properly and will greatly increase
the reception range of any of our products. Securitex and SecureCiti only carries
two types of high gain antennas- flat panel 'polarized patch' models
for 2.4 gigahertz and "yagi" for 900 megahertz. We do not
carry high gain tuners or antennas for 434 MHz equipment as amplified/
powered UHF antennas are more commonly found as
"consumer-end" electronics at stores like Radio Shack, etc..
Q6: How many wireless
transmitters/ cameras can I operate at one time?
A6: Theoretically, with our equipment, you
could operate 9 transmitters at the same time- 4 in 2.4ghz, 4 in
900mhz and one in 434 mhz. However, use of our 900 MHz transmitters on
any other channel than one may require licensing and/or may not be
able to be used. We strongly urge you to check into the legalities
before use. So, for practical purposes- 2.4 ghz with 4 simultaneous
signals + 1 for 900 MHz + 1 434 MHz= 6 signals with which you
shouldn't have to worry about potential licensing issues.
For more answers about multiple camera
systems, please refer to the FAQ answer page.
Q7: If I use more
than one transmitter, will I need more than one receiver?
A7: It depends. For multiple channel
transmitters operating at the same time (and for the same frequency),
you may choose to use a single receiver and manually switch between
channels to view and/or record activity. Should you wish to monitor
all signals at once- you will require a receiver for each transmitter.
Q8: Can you guarantee
that your equipment will work in my desired situation?
A8: No- not at all. Due to the reasons
mentioned at the top of this page- there are too many variable factors
which may impede what you'll call "desired performance".
Therefore, it is recommended that you do your homework & purchase
the best equipment you can attain. For larger projects, start small
and see for yourself with real field testing to decide whether or not
more wireless links will be beneficial to your goals. It's not going
to provide an ideal solution for everyone's situation and that's just
as realistic as it gets. That's not meant to scare away potential
customers who may be wary after having seen some of the JUNK floating
around out there.
To return to
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To purchase the
above equipment please call or e-mail to
or contact Securitex Electronic System Engineering. Our sales
personnel will get back to you.