----- Original Message -----
From: "Bill Wichers" <billw@waveform.net>
To: "Tom W8JI" <w8ji@w8ji.com>; "Shoppa, Tim" <tshoppa@wmata.com>; "Bruce"
<k1fz@myfairpoint.net>; <topband@contesting.com>
Sent: Thursday, October 24, 2013 12:10 PM
Subject: Re: Topband: Light fiber question
Um, no... Not really -- you do NOT need modulators and demodulators to use
fiber for *analog* applications. If you want to run your signal over a
commercial transport network you will (to digitize the signal and deal
with framing for SONET, Ethernet etc.). Cable TV systems run their RF over
fiber with very wide frequency ranges (50-700+MHz). I don't know dynamic
range off hand since that's not a parameter that comes up with the digital
systems I work with (we use extinction ratio instead). The downside is
that the equipment to do that is not cheap. This is what I do all day at
work (well, digital only, but optical) :-)
Sorry, but by definition that is a modulator and demodulator.
You have to convert the radio signal to light, and that involves modulating
a light beam of some type. At the other end, you have to demodulate the
light into the original baseband.
You may not recognize it as a modulator/demodulator system, but that's what
it is. You cannot just hook the coax to the fiber optic cable at each end.
73 Tom
_________________
Topband Reflector
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