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Changing modulation standards things to watch for – Channel Plus 5545 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

Cable HRC and IRC considerations

Note

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.

: This setting can be entered on any

modulator channel, A, B, C, or D, and affects all channel assignments for

that unit. Cable channels must either be

IRC or

HRC.

5500 series

all

all

Changing modulation standards

Things to watch for:

LEDs blink

Herringbone interference on ChannelPlus channel (diagonal lines)

Herringbone interference on many channels (disappears when you

remove the modulator)

... You need to have one unused channel space between

channels. The display will blink if you have made an ‘illegal’ choice. See

the section on programming.

...

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 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.

This manual is related to the following products: