PRORXD Broadcast Receiver User Guide
Commercial in Confidence
Broadcast Solutions, HD/SD Products,
PRORXD
100167
Revision: 7.0
Commercial in Confidence
Page 7-59
No
Property
Range
Description
2+7
LO Frequency
(MHz)
1880 or a correct
downconverter
frequency.
Most of our receiver units operate downconverters
to lower the frequency from microwave (L, S and C-
Band) to an Intermediate Frequency (IF) between
51 and 858MHz that the on-board tuners in the
receivers can operate with.
We find this information from the downconverter
frequency and side table in
Appendix D –
Downconverter Data
.
3+8
LO Side
Low or High
It is necessary to set which side (of the expected
incoming frequency) the LO frequency will be.
In my example the incoming frequency I wish to
receive is in S-Band, 2.25GHz to 2.65 GHz. I’ve
selected a DC-225265 downconverter with a LO
Frequency of 1880MHz. We see that 1880MHz is
lower
than 2.25GHz, thus I set the LO side to be
Low.
We find this information from the downconverter
frequency and side table in
Appendix D –
Downconverter Data
.
4+9
LNB Power
On or Off
It is necessary for the downconverters up on the
mast to have power. We send this along the IF line.
We name this LNB power and this is where you
switch it on.
LNB=Low Noise Block.
You can wish to switch LNB power off if you are
operating a third party downconverter that has its
own power supply for example.
5+10
LNB Voltage
9V or 12V
When the unit is fitted with latest tuner PCBs, the
LNB voltage is selectable.
11
LNB Gain Offset
9 typically, but an
applicable value to
suit the
downconverter you are
operating.
Most downconverters introduce gain to the RF
path. A DCB-200250 for example introduces 9dB in
its standard gain version and 19dB in the high
gain version.
To make sense of the signal strength numbers it is
necessary to apply this correction.
12
Individual LOs
Select or Clear
When cleared the LO Frequency and LO Side apply
globally to all downconverters attached to the
receiver.
When selected, new fields open up to let you set
individual LO Frequencies and LO Sides for each
downconverter. This means you could have one half
of the antennas set up for S-Band and the others,
L-Band.
Table 7-15 Downconverter Settings Pane Key
