Andrew Gabriel wrote:
In article . com,
"david" writes:

I have a co-ax cable coming from my aerial and I have two Micromark
cctv cameras that feed into a modulator which outputs at channel 38.
What I would like to do is get the cctv feed up to the loft so it can
then be split around the various TVs in the house so I can view the
cctv output on all of them. The modulator output channel is away from
any of the aerial TV output channels.

Is there anyway of economically combining two coax cables (one from the
aerial and the other from the modulator) which would then go into the
booster to be sent to each of the other TVs?


Use a passive splitter. They work in reverse as a combiner too.
They are lossy, so if your aerial signal is very weak, the addition
of a splitter might make a noticable difference.

You might also need to severely attenuate the output of the
modulator, as it's signal is likely to be orders of magnitude
larger than that from the aerial, and it could saturate the
input stage of the booster rendering the aerial signal unusable.
Try it without attenuators first, but don't be surprised if you
need to buy some.

The OP could use frequency selective combiner/splitters. The advantage there
is that the insertion loss at the specified frequency ranges on the respective
legs is very low (typically about 1dB)

For instance I use a Group A/E combiner (21-33/37-68) to combine the outputs
from my DTT and Sky boxes on UHF Chs 22 and 25, with aerial signals UHF Chs
39-66.

--
Mark
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