scope AMP1-10 MK2 Instruction Manual
Scope Communications UK Ltd, Quantum House, Steamer Quay, Totnes TQ9 5AL, England, UK
AMP1-10 MK2AMP1-10 MK2
AMP1-10 MK2AMP1-10 MK2
AMP1-10 MK2
UHF Power Amplifier MK2
UHFAMP/4
Installation & User Manual
UHF Amplifier AMP1-10
AMPUSE/4 1 07/05
UHF Power Amplifier Model AMP1-10 MK2
Overview
This amplifier is designed to increase the operating range of an already correctly
installed system. In such a system the need for a well sited transmitting aerial
should previously have been addressed. The amplifier is not intended as a
substitute for an indifferent, poorly located aerial. In this context, we would strongly
advise not to connect a simple quarter wave antenna directly to the ‘N’ type output
connector, as this will inevitably produce a strong local radiated field, which is quite
capable of causing interference to other equipment in the vicinity.
Note ! This system requires a valid OFCOM licence for operation in the UK. It is the
user’s responsibility to apply for an On-Site Paging licence on form Of21 Private
Business Radio Licence Application Form, available online at www.ofcom.org.uk
The relevant clauses on the Of21 form should be completed as follows:
Section 2, item 9. Tick “Self-Select PBR licence”
Section 4, item 28. Generally, antennas provided by Scope are Omni-Directional,
with a gain of 0 dB.
Section 4, item 30. ERP level: 0.5W as standard, 2W if the amplifier is fitted.
Warning! Alteration or modification to any part of this equipment, including operation
without a suitable antenna, will invalidate all Approvals and Warranties attaching to
the equipment. Further liability for the operation of the equipment, under the
applicable law, will pass to the user, who will absolve the manufacturer of any further
responsibility for it’s correct operation and use.
Installation
The output from the amplifier should be fed, via good quality coaxial cable, to a
dipole or beam aerial mounted high on a mast and clear of local obstructions. A
minimum cable specification is RG213 or UR67, and for runs longer than ten metres,
helical membrane (Heliax) cables are worth considering. At high frequencies, poor
quality cable and associated plugs and sockets incur high losses, and quickly negate
the theoretical improvements in system performance which a power amplifier might
otherwise bring.
The following example is presented as an illustration of potential system losses. At
460 MHz standard RG213 or UR67 cable loses 1 decibel - approximately 20% - of
the incident power for every 5 metres of length, and 15 metres (50 feet) loses 3dB.
This means that if you start with 10 watts out of the amplifier, you will get only 5
watts at the far end of 15 metres of RG213 cable! These loss figures apply only to
cable in a new, dry condition. Note that word dry, because once moisture is allowed
to enter the ends of the cable it will corrode the copper conductors, particularly the
outer braid, and thereby raise the loss to the point where the cable looks like a
reasonable dummy load, soaking up most of the transmitter power. It follows that
only good quality watertight, ‘O’ ring sealed connectors should be used. Unsealed
crimped connectors are a false economy and will result in the system failing in the
longer term.
UHF Amplifier AMP1-10
AMPUSE/4 2 07/05
At radio frequencies signal currents flow only very near to the surfaces of electrical
conductors, a phenomenon which is known as skin effect. This means that the
surface resistivity of the cheaper nickel plated and chromium plated connectors
makes a significant contribution to the losses. For this reason we would advise to
use the better quality silver plated N series connectors.
Installation
For the DC powered unit, connect the power lead provided between the transmitter
unit and Amplifier module using the 2 pin lockable connectors located on the end
chassis plates of the respective units (these are polarised to avoid reverse
connection).
Similarly, connect the RF input lead attached to the Amplifier module to the BNC
connector on the transmitter unit.
Do not attempt to increase the length of either the DC power cable or the RF input
lead as this may severely reduce the output power of the Amplifier.
For the mains powered unit, fit the mains lead into the IEC socket on the base of the
unit and connect the RF input lead as above.
The Amplifier module can be wall mounted using the fixing holes provided in the rear
chassis plate. To access these, remove the two cross-headed screws from the front
cover (DC model) or slacken the four cross-headed screws on the end plates (mains
model) and lift off the cover. Do NOT use the chassis as a drilling template, the
vibrations may cause irreparable damage to the electronic circuitry. Please also note
that the unit is only intended for indoor installation and as such should be mounted in
close proximity to the transmitter unit (this is limited anyway by the fixed length of the
RF input cable).
Note: when installing the mains powered model, ensure the battery is fitted
and connected before operating the unit. Similarly, for the DC powered unit,
ensure the battery in the ConneXions unit is fitted and connected prior to
operation.
WARNING: Do NOT apply power without a suitable antenna connected to the
Amplifier. To do so may cause irreversible damage which will not be covered
by any warranty.
Operation
The Amplifier is automatically switched into operation when the host unit transmits
and therefore requires no further user intervention. See diagrams on page 3 for
typical examples of installation.
© Scope Communications UK Ltd, 2003 All Rights Reserved
Typical Installations
UHF Amplifier AMP1-10
AMPUSE/4 3 07/05
ConneXions
Transmitter
Mains powered UHF Amplifier:
Typical Installation
Alternative in-line
Installation
UHF Amplifier
External wall mounted
dipole antenna
E
RG213 or UR67
Coaxial Cable
'N' Connector
(silver plated)
RF Out
ConneXions
Transmitter
DC powered UHF Amplifier:
Typical Installation
Alternative in-line
Installation
Power Inlet
12 to 13.8 V dc
'N' Connector
(silver plated)
UHF
Amplifier
RG213 or UR67
Coaxial Cable
External wall mounted
dipole antenna
E
Power Outlet
13.8 V dc RF Out
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