People forget, or don't know, fiber cables require modulators and
demodulators. The modulators and demodulators are not simple, and have
horrible dynamic range compared to a simple piece of coax.
I can't think of a good Ham shack application using fiberoptics for coupling
RF signals. First, the dynamic range stinks compared to coax. Second, common
mode is very easily completely cured with extreme measures.
I feel a little guilty about starting some of the common mode stuff, because
it has taken off into being far more extreme than it really needs to be. As
a general rule, if you isolate the antenna end and have a proper shack
entrance, a few beads are the most you'll need.
One of the worse things are plastic boxes and wire grounds inside insulated
boxes, and what we do on antenna with poor grounds. But it is all easily
fixed without extreme measures.
----- Original Message -----
From: "Shoppa, Tim" <tshoppa@wmata.com>
To: "Bruce" <k1fz@myfairpoint.net>; <topband@contesting.com>
Sent: Thursday, October 24, 2013 9:29 AM
Subject: Re: Topband: Light fiber question
I do not know of any analog optical coupling technology that has nearly the
dynamic range of copper.
50dB is considered quite good HF dynamic range for completely sealed
analog optocouplers. Start putting cables and junctions in there and it
has to only get worse.
Tim N3QE
-----Original Message-----
From: Topband [mailto:topband-bounces@contesting.com] On Behalf Of Bruce
Sent: Thursday, October 24, 2013 12:06 PM
To: topband@contesting.com
Subject: Topband: Light fiber question
Tim,
Good information, but I was thinking of a way for "Mr. Average DXer" to
get a connection, that is not adding noise, from his on site receiving
antenna.
73
Bruce
----- Original Message -----
From: "Shoppa, Tim" <tshoppa@wmata.com>
To: "Bruce" <k1fz@myfairpoint.net>
Sent: Thursday, October 24, 2013 5:50 AM
Subject: RE: Topband: Light fiber question
I think that is called "a remote receiver connected by optical fiber
networking". Several folks use this technology on topband. Sometimes the
remote receiver is the other side of the world.
Tim.
-----Original Message-----
From: Topband [mailto:topband-bounces@contesting.com] On Behalf Of Bruce
Sent: Thursday, October 24, 2013 11:48 AM
To: topband@contesting.com
Subject: Topband: Light fiber question
I am now using twisted pair on my receiving Delta antenna and is less
noise than the coax.
Question: Any one ever tried using light fibers as a near ultimate
transmission line from their receiving antennas?
73
Bruce-K1FZ
www.qsl.net/k1fz/beveragenotes.html
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