Lightning will find a path to earth ground with or without
that in-line pre-amp. It is nonsense to wish something will
stop, block, absorb, or filter such transients. Anything that
is going to accomplish that protection is already inside the
TV tuner.

Either it suffers a direct hit or it suffers nothing. And
that means everything in that path suffers the same current
equally. If nearby strikes were so destructive as implied,
that we routinely see cell phones and car radios damaged by
nearby lightning. Too often the 'so called' nearby strike is
really a direct strike. But that is beyond the scope of this
discussion and is already explained (using a horse as example)
in the newsgroup microsoft.public.windowsxp.basics on 11 Mar
2005 entitled "Power surge safety".

The preamp does nothing to provide transistor safety. For
transistor safety, earth ground defines that. Some inductance
in the coax can assist IF the earthing system exists. But no
earthing system means inline impedance (the pre-amp) provides
nothing.

Richard Harrison discusses this often in the newsgroup
red.radio.antenna.amateur. He posted this on 12 Dec 2003
entitled "Lightning Arrester":
A folded VHF monopole fed by coax and well grounded at the
tower top is nearly immune to lightning.

Coax, inside, rejects common-mode propagation of lightning
energy. Coax, outside, needs good grounding to make a good
path around (bypass for) protected equipment.

The equipment needs direct low-impedance grounding so that
most surge energy is dropped across the coax, not the
equipment. Coils of extra coax may be used to raise the
impedance of the outside of the coax.

In this and most every post from experienced industry
professionals, there is nothing stopping lightning damage.
Either it is given a non-destructive path to earth, or it goes
right on through that pre-amp and TV tuner, as necessary, to
find earth ground. For those blessed with basic electrical
knowledge, the transient is a current source. That means
voltage will increase as necessary to overwhelm everything in
that path. That also means everything in that path sees the
same current. Current passes destructively down that wire
EXCEPT if the human provides the transient with a better path
to earth. Earthing is the protection; not some suicidal
pre-amp or fuse.

If fuses blew, well now you know how much protection is
already inside that tuner. The fuses quit long after the
tuner had protected itself and long after the transient had
completely finished. That pre-amp provides no protection.

Ralph Mowery wrote:
While it will not protect from a direct hit it may help from the
spikes produced by near by flashes. I have a radio repeater on
top of a mountain and the phone line connected to it is my biggset
problem . I installed a couple of very low amp fuses and a couple
of coils after them. The fuses blow often after a thunder storm
but they do protect the other equipment. No doubt that a direct
hit would take out everything.