Link XP L2102/L2104 Receiver Instruction Manual Issue 1 - October 2003 Page 11 of 48
Link Research Ltd. 23/24 Watford Metro Centre, Dwight Road, Watford, Hertfordshire, WD18 9XA, England. Tel: +44 (0) 1923 200 900
Registered in London No. 2074604
Web:
www.linkres.co.uk Fax: +44 (0) 1923 241 357
L2102 & L2104 Receiver
Instruction Manual
system. Briefly, with one LED lit, 10dB of attenuation is introduced to protect the front
end of the receiver with reasonably long cable lengths. There is very little difference in
the noise performance of the system. Turning on two LEDs introduces 20dB do attenuation
which will protect the receiver front end with medium cable lengths. The noise
performance is increased slightly and the range of the system may be reduced by up to 30%.
With 3 LEDs switched on 30dB of attenuation is introduced and should only be used for very
short cable lengths. The noise performance of the system can be seriously degraded and
the range reduced by up to 75%. With no LEDs lit, there is no attenuation and this
condition should only be used for very long cables or where the signal is very weak. The
receiver front end has no protection with this setting.
1.2.4 Non-diversity system
This is the simplest system and the receive side only requires 1 antenna and down convertor
to make it work. The performance over short distances will be good, but not as good as a 2
channel diversity system. For outdoor installations where only a small area has to be
covered, non-diversity is ideal.
Generally the antenna should be placed as high as possible and in the clear. See section 2
on antennas for more information.
Connect the receiver as shown in the diagram below. Take care to keep all cables away
from potential sources of interference and/or damage (see section on cables for more
information).
NB
When connecting up the cables the receiver
should not
be powered up. The LNB power
may be active whilst cables are being connected and it is easy to make a short circuit. It is
very unlikely that any damage will be done because the LNB power supply is short circuit
protected, but it is better to be safe than sorry!
