6
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 seems low compared to broadcast
… 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.
…
See
the section on programming.
There may be little
you can do here, other than turn up the volume. Here is what is happening:
In broadcast television, the audio is compressed: The soft sounds are amplified
to be almost as loud as the loud sounds. The technical measure of this is
dynamic range, the ratio of loudest to softest sounds. The dynamic range of
video devices such as DVD and LV players is very great. Since most of a typical
movie consists of ‘soft’ sounds, the audio will seem quieter than normal
television channels. (This is also why commercials, which are the most
compressed, seem louder than the program they accompany.)
To appear to be at the same volume as broadcast channels, the audio level in a
modulator is carefully increased. In the modulator, too high of signal level can
overdrive the MTS circuits and audio performance will suffer.
… When using the TV outputs to send audio to a home theater system,
be sure the TV is in the stereo mode for external speakers. Consult the TV manual,
this is often confusing and is different for different TV brands.
!
!
No Stereo
CH
C
CH
D
VIDEO
AUDIO L
AUDIO R
CH
A
CH
B
VIDEO
AUDIO L
AUDIO R
OUTPUT
600mA
15VDC
POWER
Model 5645
Sample System Diagram
SATELLITE
RECEIVER
VCR
DVD
VCR
12:00
Video/audio out
Video/audio out
Video/audio out
CCTV Camera
at front door
CATV/Antenna
In this system, CATV or antenna
channels are available on all TVs. In
addition the following channels have
been added:
Channel 66 - Front door channel
Channel 68 - VCR
Channel 70 - Satellite receiver
Channel 72 - DVD player
RG6 coax
Model 3308 Coax panel
(Distributes to as many as 8 TVs)
3
Remove jumper for Hi-Z
(See manual)
A B C D
