Path: utzoo!attcan!uunet!cs.utexas.edu!tut.cis.ohio-state.edu!bloom-beacon!apple!oliveb!sun!crank!flloyd
From: flloyd%crank@Sun.COM (Fred Lloyd)
Newsgroups: sci.electronics
Subject: Re: TV RF transmitter wanted
Message-ID: <107726@sun.Eng.Sun.COM>
Date: 1 Jun 89 23:50:02 GMT
References: <190700040@trsvax>
Sender: news@sun.Eng.Sun.COM
Reply-To: flloyd@sun.UUCP (Fred Lloyd)
Organization: Sun Microsystems, Mountain View
Lines: 50

In article <190700040@trsvax> bb@trsvax.UUCP writes:
>
>I am interested in transmitting a TV RF signal over a distance of at least
>2000 feet.  I realize I will probably need some kind of FCC license.  Does
>the FCC grant licenses to send a TV signal of that strength?  What is the
>size, cost, weight, and wattage that I am looking at to send 2000 feet?
>
>Has anybody out there (such as robotics types) tackled the same problem?
>
>Any replys would be appreciated.


If you're up to experimenting then here's some fuel for thought:

Take an ordinary VCR and attach it's output cable to a regular TV
antenna.  For best results, get an antenna which is specifically tuned
to either channel 3 or 4, depending on the output of your VCR.  Avoid
those multi-channel "color" antennas with dozens of odd-sized
elements.  Stick with the single-channel multielement Yagi design.  You
should be able to pick up this retransmitted signal for some distance,
depending on conditions and quality of construction.  If necessary, an
MATV distribution amplifier could be used to boost the output power on
the sending antenna.  The receiving antenna should be in-line with the
sending unit (sorry, no around-the-corner operation :-).  Don't forget
to be sure that the polarization of the two antennae are the same (both
vertical or both horizontal).  Whatever the VCR is tuned to, or what
ever is playing on the tape, will be received on channel 3 (4) on
the other end.

Of course this is illegal... and the signal won't be extremely strong,
but anyway, you asked for "any" replies :-).

And now for the real DISCLAIMER:
I've never done this myself and probably would look for an alternative
(read legal) method if I wanted to extend my tv signal.  Several
devices are due to come out on the market shortly which perform this
exact function (but not on broadcast frequencies), and which it may be
possible to string multiple units together for more range.  Don't
however, look for them in Radio Shark anytime this year...

-fred


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| Fred Lloyd  KJ6RK  PP-SEL                         flloyd@sun.com |
| Sun Microsystems, Inc.                             ...sun!flloyd |
| Mountian View, CA                                                |
| (415) 336-6322                                                   |
| Disclaimer: If it ain't broke, don't fix it!                     |
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