As an addition to my last posting on this subject be careful if you see
optical cards for sale at rallies etc, they all should/must have the laser
'starburst' symbol on them, and may be labelled as either, laser product,
class 1 laser, or class 3 laser, what they will not tell you is the power
output, you will need a calibrated optical power meter for this, or the
wavelength, which could be 850nm multi
73.
Ken
M0KHW
mode, 1300nm single mode or 1550nm single mode. When I was working on
optical systems the standard BT optical connector for main network single
mode fibre was the FC type, originally manufactured by Seiko..
----- Original Message -----
From: "mal hamilton" <[email protected]>
To: <[email protected]>
Sent: Friday, December 18, 2009 9:16 AM
Subject: LF: Re: Re: RE: Noise cancelling by using optic transmission of RX
signals
Radio Amateurs BEWARE - Appliance Operators DO NOT TOUCH
G3KEV
----- Original Message -----
From: "Ken" <[email protected]>
To: <[email protected]>
Sent: Thursday, December 17, 2009 10:43 AM
Subject: LF: Re: RE: Noise cancelling by using optic transmission of RX
signals
Optical fibres are fine for transmission and remove all the problems of
interference and cross talk at a stroke, but please be careful and
observe
optical safety precautions when using lasers and other light sources. I
worked on optical systems for many years during my time with BT, and
optical
safety took priority over every thing else. All optical fibres need to
have
a perfect cleave on the ends, and the connectors be absolutely clean, if
you are not launching into an optical connector then alignment will be a
problem, similarly at the receive end.
73.
Ken
M0KHW
----- Original Message -----
From: "Horst Stöcker" <[email protected]>
To: <[email protected]>
Sent: Thursday, December 17, 2009 9:01 AM
Subject: LF: RE: Noise cancelling by using optic transmission of RX
signals
In theory it's a good Idea which I had some weeks before without working
it
out.
Years before I also have made tests with FTA (free to air) optical
transmissions with a DL2CH-Transceiver and a TRX-Kit by Aatis which is
quite
much simpler.
Even with that it was no problem to link between two points about a few
meters.
In this case you should think about an IR-LED. Unfortunately, the Aatis
receiver has a photo transistor instead of a diode. But it should be no
great deal to modify that.
The problems with FTA optic transmission for this application are imho:
- You have to be sure, that no one can be injured by the laser beam,
especially at unattended operation.
- Think about how many hours/the beam has it's full power before becoming
much weaker.
- The optics must be kept clean. This could be a problem if the units are
out of reach.
- The units have to be mounted absolutely stable. For Example, on a
swinging
fibre rod you'll never bring a laser beam exactly to the rx area.
I bet, (FTA) optical transmission just changes one problem with a few
others.
But the transmission with optical cable seems interesting.
What type of cable do you suggest? I do not think, my TOS-Link cable
would
stand weather/UV and mechanical conditions outside for a long time.
Horst DO1KHS
___________________________________________________________
Preisknaller: WEB.DE DSL Flatrate für nur 16,99 Euro/mtl.!
http://produkte.web.de/go/02/
|
