Pico Macom PIDA-550 - Manual (Page 8)

PICO MACOM, INC. 12500 Foothill Blvd. • Lakeview Terrace, CA 91342 • (818) 897-0028 • (800) 421-6511 • FAX (818) 834-7197
1 6 7
Distribution
T
he output levels of the modulator should be the same as the output of the off-air strip amplifiers. The M860
modulators are usually combined with either the SP860 signal processor, LBS/MBS/FMS/UBS series strip
amplifiers. Two methods are suggested to combine strip amplifier, modulator and processor outputs which
are then amplified with the PIDA distribution amplifier serving as a launchamp.
T
he PHC-12U twelve channel passive headend combiner consists of two rows of directional couplers
combined by a hybrid splitter. The directional coupler combining provides high isolation (40 dB) between
the inputs. Normally, the odd channels are combined on one row while even channels are combined on the
other row of directional couplers. The combiner loss is 16 dB per channel.
A
nother method of combining signals uses three hybrid splitters per headend rack. The odd channels are
combined in one splitter, the even channels in another splitter and the two splitters are combined to a single
output with a third splitter. Each rack is then combined with a final splitter prior to the PIDA amplifier.
NOTE :
*
Denotes either LBS, MBS, HBS or FMS model numbers.
I N S T A L L A T I O N
Ch. 2
Ch. 3
Ch. 4
+36dBmV +60dBmV
SP860
*BS
V
A
+52dBmV
+52dBmV
+52dBmV
+10dBmV
+14dBmV
+10dBmV
6dB PAD
RF
IN
RF
IN
M860
PHC-12U
-16dB
PIDA-*
ATTENUATOR PAD
SP860
*BS
V
A
+60dBmV
+52dBmV
+52dBmV
+10dBmV
+14dBmV
+10dBmV
EVEN CHANNELS
Ch. 2
Ch. 3
Ch. 4
ODD CHANNELS
+45dBmV
+45dBmV
+38dBmV +60dBmv
8dB PAD
RF
IN
RF
IN
PIDA-*
ATTENUATOR PAD
M860S
*PIDA-550, 750, 1000