TELE-audiovision - The World’s Leading Digital TV Industry Publication - page 50

TELE-audiovision International — The World‘s Largest Digital TV Trade Magazine
— 07-08/2014
We decided to test this
device on our toroidal an-
tenna on which we have
a number of LNBs. We
measured one of the ex-
isting LNBs - dedicated
for ASTRA 28.2° East and
then another one mounted
in the position to receive
ASTRA 19.2° East. The
first LNB was a very good
contemporary LNB with
NF=0.1 dB. We took these
measurement results as
our reference levels.
Then, we removed the
LNB for ASTRA 28.2° and
mounted in its holder the
MB04 LNB. We also con-
nected the MB04 with the
second reference LNB for
ASTRA 19.2° East.
As you can see in the
graph, the MB04 output
was stronger than that
of the reference LNB by
2 through 8 dB. It means
than you can use long coax
cables with the MB04.
When we compared sig-
nal quality we noted that
its MER was 0.5...2 dB low-
er than that of 0.1dB LNB
reference. Which makes it
a very good choice for reg-
ular DTH installations.
On the following graphs
we tested the MB04 impact
on the signal coming from
the second LNB. The signal
was attenuated by a couple
of decibels what is abso-
lutely normal for a DiSEqC
switch. The strong point is:
its MER did not change. So,
signal quality at the MB04
1...,40,41,42,43,44,45,46,47,48,49 51,52,53,54,55,56,57,58,59,60,...164
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