list is the return loss. Are the 90dB ones solder backed or epoxy? Are
they made utilizing a PCB design, or are the components just soldered
together and stuck in the housing?

What would be the difference in having a solder back or an epoxy?

A splitter which has a solid (or completely seam-soldered) metal
enclosure is going to be more RF-tight than one which simply has a
poured-epoxy or plastic back. The sealed-metal variety will keep the
cable-TV signal from leaking out, and will keep other signals from
leaking into the cable feed.

This is beneficial for several reasons, all having to do with the fact
that many cable-TV channels use frequencies which are not authorized
for TV-broadcast use - they're assigned to other radio services
(police, fire, aircraft, amateur).

Signals leaking out of a cable-TV wiring plant (e.g. from a poorly
built splitter, or an unterminated port on a splitter or junction box)
can interfere with these other radio services. Similarly, a nearby
transmitter operating on these frequencies can leak into an open port,
mix with the cable-TV signals, and cause video or audio distortion or
interference.

Cable-TV companies are required by the FCC to keep their wiring plants
"tight", and they usually run "sweeps" of residential neighborhoods
looking for signal leakage. If they find it, they'll either fix the
wiring fault (if it's outside the building), or require that the
building owner or tenant fix the problem as a condition of continuing
to receive cable TV service.


--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
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