On Sat, 20 Jun 1998 02:23:06 GMT, antis...@here.not (john r

If you're seeing something on Channel 11, it's not coming from
Loma Prieta.  I can see Loma out my window and there's nothing on
Channel 11.

That's ARF, as in woof, bow-wow, arf and howl.

Radio Shack and high tech in the same sentence?  Surely an
oxymoron at best.  I'm still downloading the 844KB PDF file at
500 bytes/sec (Metricom at its worst).  It should be done
tomorrow.

I built something like that about 1977 BC (Before Cable).  The
new MMIC (Mini Microwave Integrated Circuits) and low noise
GaAsFET's make it much easier.  The basic idea is to put the RF
amplifier as close to the antenna as possible.  Any kind of
antenna will do as there is no sane way to build a broadband
horizontally polarized antenna that will work from 54 to 800MHz
and still have reasonable pattern, gain and VSWR.  Therefore, you
start with a convenient length of wire, characterize it to the
last decimal point, and spend a few zillion clock cycles
calculating a matching network.  It actually turns out to be
rather a rather simple design.  You then mix the signal with your
satellite feed (hint: off the air tv is 54->800Mhz, satellite
block downlconvert is 950-1450Mhz, so there's room).

However, placing it at a random location is guaranteed to screw
up performance.  You'll get reflections from anything metal
around, the pattern will look like a mess, and the presence of
the 850-1450 signal on the same coax might cause intermod.
Mounting it under the eves is mechanically convenient, but an
electrical abomination if you have any metal nearby (rain
gutters?).  The direction is also important as the dipole has
zero gain in two directions.  Getting a signal from the direction
of the house (through the house) seems more than improbable.
Theoretically, the perfromance should be far worse than a decent
amplified rooftope TV antenna and rotator.

What bugs me is the claim that it will "pull in signals folks
didn't know they could get".  This is the famous "my product is
better" claim, where there's no clue as what it's better than.  I
don't believe it.

There's nothing inherent in this scheme that provides any level
of superior performance.  There also has to be a minimum level of
signal to work with.  You can't amplify a signal that isn't
there.  If you're compareing this scheme with a pair of indoor
rabbit ears or one of those rip-off radar dish like set-top
amplified antennas abominations, I can see where moving the
antenna outdoors would produce new stations.  However, a decent
amplified antenna and rotator is far superior to this
contraption, especially mounted under the house eves.  Yech.

If I had to recommend an antenna, it would be a reflector backed
bow-tie antenna for UHF only.  These look like a flat barbeque
grill with a metal bow tie in front.  Stick a decent MMIC
amplifier at the antenna and plant it on top of a rotator.  Feed
it with RG6u (not RG59u) and point it where you want to view.
I'll go into why commercial yagi TV antennas suck in another
tirade.

Still downloading the PDF file.  Maybe tomorrow.

--
Jeff Liebermann  150 Felker St #D  Santa Cruz CA 95060
(408)699-0483 pgr (408)426-1240 fax (408)336-2558 home
http://www.cruzio.com/~jeffl   WB6SSY
je...@comix.santa-cruz.ca.us   je...@cruzio.com