On August 24, 2009 at 22:56, winesmile said...
I have video cameras modulating to monitors on a standard CATV feed.
Ok.
I've added 2 monitors, but the diplexer that is installed has only the one vhf/uhf output and I need three. I do not need the Sat out at all.
I have no idea why you've got a diplexer there, as you mention CATV, not satellite. And if it's CATV, then it's a splitter, not a diplexer. And both types of devices have three ports -- what is connected to what on them? I mean, if it's a splitter, then you're splitting a signal in two, and you have two ports, or you're combining two -- hey! maybe modulator and cable! and you've only got one output of the combined signal.
Saying it's that, take that output and feed it to a three-way splitter. Most three-ways have one port that is about 4 dB lower than the input and two ports that are 7 or 8 dB lower than the input. Connect the longer run to the -4dB port.
Can somebody recommend a fix and should it be amplified?
Oh, I just did. Should it be amplified? Well, if these are analog signals and you have no snow, then you've got enough signal. If digital and you have no tiling, then you've got enough signal. But if it's digital, you're likely to not be able to see the cameras while losing several digital channels, as their frequencies will likely overlap. The modulators have to be on frequencies where digital signals don't get taken out by the analog signal, nor the analog taken out by digitals.
The pictures looks fine with the diplexer, but we tried an old splitter and the picture really got poor - lots of grain, etc.
Old splitter. You didn't have a new one? Two-way? Three-way? Four-way? Eight-way? Three-way connected wrong (it can happen)?
Again, the diplexer. A diplexer is for combining or separating different ranges of signals, for instance satellite and antenna. In fact, a speaker crossover is a separating diplexer, sending bass to the woofer and highs to the tweeter. I don't understand your wiring setup if a diplexer is used.
