4
23)Safety Check - Upon completion of any service or repairs to this product, ask the
servicetechnician to perform safety checks to determine that the product is in proper
operatingcondition.
24)Wall or Ceiling Mounting - The product should be mounted to a wall or ceiling only as
recommendedby 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.
Thisreminder is provided to call the CATV system installer's attention to Section 820-40 of the
NECwhich 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
cableentry as practical.
Noteto CATV system installer
POWERSUPPLY REPLACEMENT
Replacedefective power supplies only with parts specified by the manufacturer.
FigureA
Exampleof antenna grounding as per
NationalElectrical Code, ANSI/NFPA 70
9
Thingsto watch for:
Herringbone interference on ChannelPlus channel (diagonal lines)
Herringbone interference on many channels (disappears when you
removethe 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
movingthe ChannelPlus channel to another number. Youmay have to add
alow 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
thesemodulators.)
No color on ChannelPlus channels … You may have chosen the
incorrect cable standard. Not all televisions can accommodate the
1.25MHz frequency differencebetween the H and I cable standards.
No picture
WeakChannelPlus 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
surethe TV is on UHF 16 rather than CATV 16. UHF 16 and CATV16 are at
differentfrequencies.
… If theTV has a separate UHF input,
besure that it is connected.
… The left and right audio inputs are combined for
monaural. Forproper 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
thesection on programming.
CableHRC and IRC considerations
Mostcable 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 canbe reprogrammed to use HRC assignments by entering the
number“ 98”. Set to IRC by entering a “99”. Both of these settings are only
usedfor setting HRC/IRC.
5500 series
Changing modulation standards