david wrote:
Thanks but the aerial signal is, at times, very weak and so I don't
think this would work - but thanks for trying.

David


I imagine then there is already a multi-output preamp in the loft to
distribute the weak TV signal.
Option 1. get a second preamp for the antenna and combine the CCTV
signal with the boosted antenna signal at its output, using the passive
splitter someone else mentioned, so there is little or no antenna signal
loss.
Option 2. Get an aymmetric splitter, say -0.1dB (approx) & -20 dB.
This will give little loss on the -0.1 dB port. A ham radio friend
could probably knock one up for a few pence as similar devices are
regularly used for SWR indicators.
Option 3. Plug your CCTV output into an indoor TV antenna which will
act as a local radiator. Point this up toward your outdoor antenna from
inside the loft and the outdoor TV antenna should pick the signal up. I
haven't tried this, its just a wacky idea (and marginally illegal).


John