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Re: Fiber Optic Information



We do this stuff in CATV all the time at bandwidths up to 800 MHz, it's 
called Fiber Nodes,

Essentially, Baseband TV signal (Composite audio/Video for a given channel) 
to a Modulator to put it at the frequency or channel you really want it on, 
then combine the signals to a series of channels, then into a Fiber 
Transmitter at the "shack" to convert the Channelized RF to Fiber Optic 
Signals, Send over Single Mode Fiber cable (usually a single fiber at 1550 
nM) to a Fiber Receiver or Node, the node has the amplification within in 
it to send a signal out onto the Coax at up to 56 dBm for transmission over 
the  the Coax plant.  Power must be supplied at the Receiver site so a a 
power amplifier wouldn't be a problem, the reverse path is similar, but is 
sent back to the central site on the lower bands (20-50MHz and at 1330nM on 
the same fiber) over the coax/fiber set up.  At the central site a splitter 
provides the 1330 to a receiver and prevents the high power fiber 
transmitter power from getting to the "receive" receiver.  The information 
in the case of CATV is set top box ID, CableInternet, or Telephone voice.

Biggest problem is the cost..


Tranmitter is 10-15000 dollars, 1:2 optical splitter is 1500 dollars, 
optical receiver/node is 1500 to 3000 dollars depending on the features, 
(oh depending on the brand and types this could all be controlled by 
PC/Digital SNMP type data on the fiber) and at just about any distance 
between the transmitter and the receiver up to 60KM.  (Oh don't let single 
mode fiber scare anyone, it is less expensive than MM, but typically you 
must use commercially installed SC/APC connectors.)

There is much of this in the 1330nM starting to show up on the secondary 
(trading older systems for newer systems) market within CATV.

(Oh by the way, I have personnally designed and installed HFC (Hybrid Fiber 
Coax) Systems, so I come with a little knowledge and experience in this 
area, Now using it for Ham radio remoting of radio/antenna sites would be a 
use I think many of us especially in the ARES/RACES arena might like to 
try... (for instance I have a water tower about 3/4 of a mile from the EOC 
that would make a great antenna site, I even have permission to use it but 
haven't figured the best way to remote my antennas/radios yet....)

   At 10:01 AM 1/11/00 , Jon Ogden wrote:
 >on 1/10/00 22:55, Ryan K. Brooks at ryan@inc.net wrote:
 >
 > > What do you mean by "feedline"... obviously not for RF...  do you mean for
 > > rotor
 > > control?  If so, should be no problem... even indoor multimode stuff is
 > > incredibly tough.   If it's not tough enough, go to a riser-rated version.
 >
 >Well, you could have a fiber optic feedline for your voice or data
 >communications link as well.  You would need a fiber to RF converter at the
 >antenna.  It's not a half bad idea as you would basically be able to convert
 >your received RF directly to fiber and then you'd be able to receive in the
 >shack with virtually no loss.  You'd just need a receiver in the shack
 >capable of taking and converting from fiber back to RF so you can listen or
 >talk on your rig.  They do stuff like this in the commercial industry.  I've
 >not seen it for ham stuff but it could be done.
 >
 >73,
 >
 >Jon
 >KE9NA
 >
 >
 >--------------------------------------------------------------------------
 >The Second Amendment is NOT about duck hunting!
 >
 >
 >Jon Ogden
 >
 >jono@enteract.com
 >www.qsl.net/ke9na
 >
 >"A life lived in fear is a life half lived."
 >
 >----
 >Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
 >To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org

Bob Brandel
KG4CGP
Emergency Coordinator, Spotsylvania County, Virginia
ARES Officer
Grid FM18
Roanoke Division, Virginia Section
Member ARRL, AMSAT, ARES, Rappahanock Valley Amateur Radio Club (147.015), 
Woodbridge Wireless


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