Ghosts on the Picture
1. Terminate all unused ports with 75
Ω
terminator
model 2101.
2. Check for low quality combiner in system.
Replace with high isolation combiner, HS model
combiner.
3. Check the type of coax used in system. Inadequate shielding in
coax will cause ghosting. Pull new coax (RG6 quad).
Low Channel Pictures are Good, High Channel
Picture is Grainy
1. Place a tilt compensator in line after the amplifier
and increase amplifier gain until the higher
channels look good.
2. Check frequency specifications on all splitters and amplifiers in
system. Replace any that are not broadband 5MHz to 1GHz.
Low Channels are Wavy Vertical Lines, High Channels are Good
1. Unplug the modulator
a) Channels look good : problem is beat frequencies or
unbalanced cable vs. modulator.
1. Decrease modulator power by adjusting attenuator (red
knob on back) or use external attenuators before it is
combined with the cable TV signal.
2. Use a 9 or 12dBmV tap in reverse instead of the supplied
combiner.
3. Install a 5 or 10dBmV tilt compensator to reduce low
channel power.
4. Amplify cable TV before you combine modulated signal to
balance.
b) Low Channels are still bad : bad component in system.
1. Check signal at source without splitters, amplifiers etc. in
the system.
2. Read system installation checklist.
3. Trace picture from beginning to end. Use process of
elimination.
c) Picture still has wavy lines at the source
Call for cable company service. They have a bad component in
their system Garbage in equals garbage out.
TVs not Receiving all Channels Being Distributed
1. Check coax, if RG59 replace with RG6.
2. Check all splitters and amplifiers for broadband specifications.
3. Check TV specifications for available channels.
aimed at the sun or a reflection.
4. Adjust camera lens - see lens manual.
Modulated Picture is Too Dark
1. If baseband video is being split with a Stereo Loop Kit or loop
through quad, set impedance matching switch (termination
switch) to 1
ΚΩ.
2. If modulator is a set top style, adjust video level adjustment
potentiometer on the bottom of the chassis.
3. If the video source is not being split, check input source
directly into a TV.
4. Adjust the video level adjust pot on the chassis of the set top
units to the proper brightness.
5. Check all connectors for 75
Ω
.
Noise on the Audio
1. Insert grounding block in line and ground coax cable before it
enters the TV.
2. Use professional grade audio/video interconnect between the
components and the modulator.
Audio is Too Low
Use a Y-Connector to combine the left and right audio before entering
the modulator.
Herringbone in Picture on Modulated Channel
Disconnect modulator from local channels an check modulated
channel.
A) If there is programming move the modulated channel.
B) If the picture is snowy, use a #3102-78 low pass filter to block
noise or data coming in from cable company.
C) Separate modulated channels by two channels.
Horizontal Bars Rolling Through TV Picture
1. Check for a component of the system to introduce
DC power into the system. Disconnect that
component and check TV. If the hum bars stop, use a DC blocker
down stream from that component to block the power from
getting to the TVs.
2. If the rolling is only on the modulated channels,
check for impedance mismatch by adjusting the
video level adjustment pot.
Vertical Bars Rolling Through TV Picture
Check for AC power getting on the line. Use a ground breaker in line.
Black and White Lines on one Local Channel
Move modulated channel up to a new channel. If
problem persists and all of the inputs of a multiple
input modulator are not being used, check default
channels on modulator to see if default channel is
set to the same channel that the problem channel
is set to.
Flashing at the Top or Middle of TV Picture
1. If flashing is on modulated channels, turn up
attenuator/down gain of modulator.
2. If flashing is on local channels turn down gain or
attenuate output of amplifier.
3. Install filter #3102-80 to clean up channels.
Picture is Tearing
Possible impedance problem. Check that impedance switch is set to
75
Ω.
O u c h!!!
