Message-ID: <200912291031040414.59AABDD1@smtp2.numeo.fr>
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References: <1542517694@web.de>
 <6F962616C1CC4C1B844AF099CB1BB55D@lindavideo>
 <000f01ca7fc2$c666f6a0$0301a8c0@your91hoehfy9g>
Date: Tue, 29 Dec 2009 10:31:04 +0100
From: "John RABSON" <john.rabson@numeo.fr>
To: rsgb_lf_group@blacksheep.org
Mime-Version: 1.0
Subject: Re: LF: Re: Re: RE: Noise cancelling by using optic
  transmission of RX signals
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Agreed we should be careful.  My Creative Labs soundcard (external USB) ha=
s SPDIF optical connectors as well as electrical.  The Optical Out connect=
or emits a faint red light but I can't find any mention of safety in the=
 user manual.

F5VLF

*********** REPLY SEPARATOR  ***********

On 18/12/2009 at 09:16 mal hamilton wrote:

>Radio Amateurs BEWARE - Appliance Operators DO NOT TOUCH
>
>G3KEV
>
>
>----- Original Message -----
>From: "Ken" <ken.h.wright@btinternet.com>
>To: <rsgb_lf_group@blacksheep.org>
>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 St=F6cker" <horst.stoecker@web.de>
>> To: <rsgb_lf_group@blacksheep.org>
>> 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 workin=
g
>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 becomi=
ng
>> 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 f=FCr nur 16,99 Euro/mtl.!
>> http://produkte.web.de/go/02/
>>
>>
>>
>>