Installation Procedures; Frequency Offsets - Pico Macom PFAM550SUB Installation And Operation Manual

I N S TA L L A T I O N

Installation Procedures

Adherence to these precautions will help prevent problems
during initial installation of the PFAM 550SUB.
1. Connect the I.F. jumper from the I.F. output to
the I.F. input on the rear panel.
2. Connect the PFAM 550SUB to a 115 VAC
ground-ed receptacle. Observe the lit LED light
indicating power is on.
3. Using a signal level meter or spectrum analyzer,
set the output level.
4. Check the aural carrier level. It should be set at
15 dBmv below the video carrier.
.
WARNING: When connecting the PFAM 550SUB
directly to a TV set, attenuate the output
sufficiently to prevent overdriving the TV. The
front panel test point is useful for monitoring
modulator output.

FREQUENCY OFFSETS

T
he Federal Communications Commission
requires that cable system modulators which
operate in the aircraft communications and
navigation bands be offset in frequency by 12.5
FREQUENCY
108 to 118 MHz .................................... A,B,C ................. 14,15,16 ............. 12.5 kHz
118 to 137 MHz .................................... A-1, A-1 ............. 99,98 .................. 25 kHz
225 to 328.6 MHz ................................. K - DD ............... 24-40 .................. 12.5 kHz
328.6 to 225.4 MHz ............................... FF ....................... 42 ....................... 25 kHz
335.4 to 400 MHz .................................. GG- QQ .............. 43-53 .................. 12.5 kHz
Harmonically Related Coherent (HRC) video carriers and Incrementally Related
Coherent (IRC) video carriers are CATV channel assignment methods to reduce the effect
of beat products. The technique is used in expensive phase-locked headends where all
units are tied to a master 6.0003 MHz oscillator with a maximum error of 1 Hz.
5
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CHANNEL
5. Connect a 1.0 volt peak-to-peak video source
to the "VIDEO IN" on rear panel. Connect
the "RF OUT" to a TV set, and compare the
contrast and brightness to a known signal
(use off-air signal to insure a proper
modulation level). If necessary, adjust the
video modulation until proper contrast is
observed.
6. Connect an audio source to the "AUDIO IN" on
rear of the unit. Set audio mod-ulation (peak
deviation) to 25 kHz with the audio modulation
adjustment. A known off-air signal and a TV
may be used to set adjust-ment for equal audio
level.
7. Connect the "RF OUTPUT" to a proper
combining network.
kHz. The PFAM 550SUB PLL oscillator is factory
set to comply with FCC requirements for frequency
accuracy (+/- 5 kHz) in the aeronautical
communication and navigation bands.
NUMBER OFFSET