Things to watch for, Changing modulation standards – Channel Plus 5515 User Manual

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23) Safety Check - Upon completion of any service or repairs to this product, ask the

service technician to perform safety checks to determine that the product is in proper
operating condition.

24) Wall or Ceiling Mounting - The product should be mounted to a wall or ceiling only as

recommended by the manufacturer.

25) Heat - The product should be situated away from heat sources such as radiators, heat

registers, stoves, or other products (including amplifiers) that produce heat.

This reminder is provided to call the CATV system installer's attention to Section 820-40 of the
NEC which provides guidelines for proper grounding and, in particular, specifies that the cable
ground shall be connected to the grounding system of the building, as close to the point of
cable entry as practical.

Note to CATV system installer

POWER SUPPLY REPLACEMENT

Replace defective power supplies only with parts specified by the manufacturer.

Figure A

Example of antenna grounding as per

National Electrical Code, ANSI/NFPA 70

9

Things to watch for:

Herringbone interference on ChannelPlus channel (diagonal lines)

Herringbone interference on many channels (disappears when you
remove the modulator)

...

You may have chosen a channel number that is not completely vacant.
Distant UHF stations may be un-watchable, but will cause interference if
you try to try to create a new channel at the same frequency. Also, cable
companies often have extra signals where there should be none.

Try

moving the ChannelPlus channel to another number. You may have to add
a low pass filter to remove cable company noise.

… The high output of the ChannelPlus modulator

can overdrive many RF amplifiers. Reduce the RF output using an
attenuator. (ChannelPlus coax panels are designed to take the full output of
these modulators.)

No color on ChannelPlus channels … You may have chosen the
incorrect cable standard.

Not all televisions can accommodate the

1.25MHz frequency difference between the H and I cable standards.

No picture

Weak ChannelPlus UHF channel

Audio volume is low

… Verify that the video source is on and is producing a video

signal. Check that the TV and the modulator are tuned to the same channel.
For example, if the modulator is broadcasting on UHF channel 16, make
sure the TV is on UHF 16 rather than CATV 16. UHF 16 and CATV 16 are at
different frequencies.

… If the TV has a separate UHF input,

be sure that it is connected.

… The left and right audio inputs are combined for

monaural. For proper audio level, both right and left inputs must be used. If
you have a mono source, connect it to both right and left inputs using an
RCA ‘Y’ connector.

See

the section on programming.

Cable HRC and IRC considerations
Most cable services use IRC frequency assignments. This is the default for
the ChannelPlus

modulators. However, if the cable service

uses HRC or the TV appears to search for the "house channels," the
modulator can be reprogrammed to use HRC assignments by entering the
number “ 98”. Set to IRC by entering a “99”. Both of these settings are only
used for setting HRC/IRC.

5500 series

Changing modulation standards

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