Power unit
proPSU11C
or
proPSU11F
outlet
proOUT11C
OUT
IN
proUSM11M
or
proUSM11H
Page 3
Page 2
Powering and power units
All preamplifiers require a 12 volt DC power supply and are compatible with the
proPSU11C, proPSU11F and proPSU12F power units. They may also be powered from
PRO
ception multi-way preamplifiers types proAMP24, proAMP26 and proAMP28. The
multi-way versions, proUSM12M, proUSM12H and proUSM14M, may be powered via
any of their outputs.
Signal connections
All connections must be made with a good quality coaxial cable, such as cable
benchmarked under the CAI scheme. Cheap cables with poor braid coverage should be
avoided, as should cables with aluminised plastic foil screens, since it is difficult to make
reliable connections to these.
Recommended cable preparation details are shown in
Fig. 6
for cables with and without a
foil screen.
Location and mounting
In general the aerial and preamplifier should be mounted in a clear high position with a
good view toward the TV transmitter. The preamplifier location should be chosen to
minimise the risk of interference; e.g. avoid having the aerial, preamplifier or cabling
close to power and telephone lines.
For best noise performance the input cable from the aerial to the preamplifier should be
kept as short as practicable, but do not install the preamplifier amongst the elements of
an aerial. With a centre-mounted aerial, the preamplifier should be mounted on the
mast at least one metre below the closest part of the aerial. With a rear-mounted aerial,
the preamplifier may be positioned behind the aerials reflector, provided this is of the
grid or mesh type.
Methods for mounting the preamplifier are illustrated in Figures 4 and 5. The cable tie
fixing is intended to support the weight of the preamplifier only. Cables should be taped
to the mast at intervals of approximately 400 mm to ensure that their weight is adequately
supported.
proUSM11H
Power unit
proPSU12F
proUSM14M
Outlets proOUT11C
proUSS12 splitter*
IN
*proUSS12P
if installed on
powered leg
Power unit
proPSU11F
OUT
IN
Outlets proOUT11C
*Tap
*Tap
75 ohm
termination
*NB choose tap values to give
approximately 6 dB gain from
antenna to outlet plates, allowing
for cable losses.
Fig. 1 Basic masthead amplifier installation
Fig. 2 proUSM11H in a simple distribution system
Fig. 3 Example multi-way installation showing alternative ways of splitting outputs.
Fig. 4 cable tie fixing
Fig. 5 fixing to flat surface
When connecting the cables, take care to tighten all connections, taking particular care
with the braid clamps, which should be as tight as possible, without crushing the cable.
The importance of achieving sound braid connections cannot be over-stressed. Ensure
that the sliding cover is firmly closed once connection is complete.
OUT
IN
OUT
IN
IN
OUT
IN
OUT
Fig. 6 Recommended cable stripping details
For cables with
foil screen
6 mm
6 mm
6 mm
4 mm
For cables
without
foil screen
