Topband: Light fiber question

[Tom W8JI]

----- Original Message ----- 
From: "Bill Wichers" <billw at waveform.net>
To: "Tom W8JI" <w8ji at w8ji.com>; "Shoppa, Tim" <tshoppa at wmata.com>; "Bruce" 
<k1fz at myfairpoint.net>; <topband at 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