We are often asked: "How long can the cable be from our
Active Antennas to the Headend".
- Coax cable has higher losses at higher frequencies and this
is what is known as TILT~!
- This can also be referred to as "SLOPE" and needs to be
considered in any coaxial CATV cable run.
- Our antennas have an internal amplifier that is designed to
compensate for 100 ft or 30 meters of RG-6 cable.
- Tilt compensation has been applied in the amplifier to
boost the higher UHF signals so that when they reach the head end the
levels are more or less equal. Longer lengths will attenuate
beyond the capability of the amplifier. It is possible that weak
signals in the high UHF band will be driven close or into the noise
floor where they cannot be recovered.
- The amplifier also compensates equally for approximately
150 ft of RG-11 Cable. For longer lengths, up to 200 ft use RG-213 or a
cascadable tilt amplifier placed in a critical position on the string
or branch.
- We commonly supply 15dB Tilt
Amplifiers for use on Navy
ships to boost signals coming from a CATV shore source and have a long
run across the pier and then to the Headend. Ref. PRA-420T,
PRA-422T Power supply and Line Amplifier (Tilt version)
- Tilt or Slope loss
can also affect video on video cables
with long runs and thus reduces the bandwidth or high frequency content
of the video signal, which, in turn, reduces the picture sharpness. At
Satellite Baseband frequencies the effect is very pronounced but the
signal is relatively narrow band. For runs greater than 150ft., fiber
optics is often used.
Our
active antennas are 75 Ohms impedence normally but we can supply at 50
ohms when requested. It is mearly a small ferrite change in the
internal amplifier and a different 50 ohm cable is used and of course a
different connector. We use F connectors at 75 Ohms and BNC connectors
at 50 Ohms.
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