Channel Vision Stereo Receiver Setting Up TV Channel Range, System Design Considerations

CVT 3ub/uhf Basic Setup

Source A/V Inputs

Cable or

Antenna

CVT 3UB/UHF

Channel Vision

MULTI ROOM VIDEO TECHNOLOGY

CVT - 15PIA

HS-2

HS-3

Setting Up TV Channel Range

Example of Dip Switch Settings

Switch Band/Channels

** Cable (59-86see note ) ** below

Cable (65-135)

Antenna (14-78)

Antenna (14-39) &

Cable (91-135)

Hi - Z

75Ω

1 2 3 4

differences in signal strength may cause interference.

That's all there is to it. The information on the following pages will help you configure more sophisticated home "networks" but is not necessary for basic setups.

System Design Considerations

Sophisticated home "networks" involving many TV sets are feasible with the CVT Modulator, but care must be taken to design an optimum TV signal distribution system.

TV sets are designed for signals around 10dBmV. Signals substantially below 0dBmV result in weak, fuzzy, snowy pictures. FCC states 0dBmV minimum at TV and 15dBmV maximum

Signals above 10dBmV may overdrive older TV sets which don't have modern automatic gain controls (which can handle signals to 40dBmV). An inline attenuator (pad) can be used to reduce these signals, and to balance radically different signal strengths at all your TV's.

Signal strength decreases with coax cable length, and through connectors, splitters, and combiners, so it's important to determine how much cable and what in-line devices you'll be using, and adjust your input signal levels with amplifiers at the front end or in-line on your network to compensate for the line losses. The charts on the back of these instructions will help you calculate likely losses through coax cable runs and splitters.

In-line amps are powered through the coax cable and can be used to achieve modest signal strength gains; more powerful, a/c powered amps offer more amplification (and usually adjustable gain and tilt too). Your system should provide 10dBmV to every TV (maximum is 15.5dBmV, per the FCC).

Reverse isolation is used to prevent the signal from your CVT from leaking out to the antenna or cable input. Reverse isolation is accomplished by placing an amplifier between your antenna or cable company input and the CVT combiner. This prevents the CVT signal from propagating back up the input line.

Another way to prevent leakage from your system is to cap all unused coax cable ports on you network with appropriate terminators.

Bandpass filters stop unwanted frequencies while passing all others along. They're handy if a channel you want to use for a CVT source is already in use.

Taps are used to redirect a portion of a signal from the "main" trunk line while passing the remaining signal strength through. For example, a 12dBmV tap would pass 29dBmV from a 30dBmV trunk line signal and pass the remaining 18dBmV to a branch line (minor signal loss of 1dB would occur in the trunk line leaving 29dBmV)

Demodulators are used to demodulate the output of a cable box converter, making it possible to assign the cable signal to any channel (cable boxes usually limit your choices to channel three or channel four). Use a demodulator to "condition" the cable signal before assigning it to a CVT input line.

**Note: When using channel range settings 59-86 you must set the dip switches, plug in the unit, set the front display to your desired channel, unplug the power again and then your channels will work.

Note: Be sure to remove power from outlet before changing DIP switch settings.

Note: Switch positions are relative to back of modulator.

Note: Black indicates where the switch should be.

Video Level (bottom)

Bottom View

					C	B	A
							Video
							Input
Fuse
							L-Audio
							Input
					1KΩ
			10	30	75Ω		R-Audio
							Input
120 VAC	TV Band	RF	Attenuator Impedance
Input	DIP	Output		DIP
	Switches			Switches

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