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Re: threat to 2.4 GHz.?

 > Date:          Tue, 7 Mar 2000 09:40:19 -0500 (EST)
 > From:          Bob Bruninga <bruninga@nadn.navy.mil>
 > To:            Andrew Reynolds <calliban@sinnfree.sinnfree.org>
 > Cc:            amsat-bb@AMSAT.Org
 > Subject:       Re: [amsat-bb] threat to 2.4 GHz.?

 > On Tue, 7 Mar 2000, Andrew Reynolds wrote:
 > ... [a system] that used a 2.4 GHz. transmitter to distribute TV 
 > > audio signals over "an entire house" with what looked like a small
 > > omni antenna on top of the transmitter box.
 > Yep, these are the WAVECOMM's and look-alkes.  ATV users are buying them
 > up like hotcakes since they make great ATV links.  WIth some amateur mods
 > you can get up to 20 dB more out of them for reasonably good FM TV links
 > over a few km.

 > My approach is to try to get a 2.4 GHz ATV OUTPUT with the highest
 > possible power output I can ontop of the water tower and to keep it busy
 > and radiating as often as possible.  TO burn a hole in the frequency so to
 > speak.  SO that when we need the frequency for HAM use or to quiet the
 > frequency for P3D, "we" have control over the channel, and not the
 > cousumers and their set-top-boxes.
 > These devices have 4 selectible channels, of which only 1 or 2 is in the
 > amateur band, so let them move to the non ham channels.

They are hot on ATV and are very interesting devices.  I have read that 
some clubs are allready using two of them back to back as ATV repeaters!
The basic wavecom transmitter puts out 0.9mW as I recall.  You can remove
a 9db pad on the circuit board and add a ERA-5 MMIC to get 60-100mW out.
There is a 1w PA available as well.  You can also buy aftermarket PIC
chips for them to extend the coverage of the PLL into the 2.3Ghz ham

My advice would be:

Look up the PC Electronics web page first.  Buy the COS board for the
units (this makes them into a repeater), build two slot antennas and a
1w PA.  With two antennas suitably seperated and two bandpass
filters, you have a ATV repeater on the air.  I have heard reports
that some ATVers have already used Wavecoms for mobile ATV
on 2.3Ghz!  

Expect more of the Wavecoms on the air.  Its a cheap way to get on
ATV and on the microwave bands.

 > Bob
--73-- David WA0AUQ

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