Message-ID: <000f01ca7fc2$c666f6a0$0301a8c0@your91hoehfy9g>
From: "mal hamilton" <g3kevmal@talktalk.net>
To: <rsgb_lf_group@blacksheep.org>
References: <1542517694@web.de> <6F962616C1CC4C1B844AF099CB1BB55D@lindavideo>
Date: Fri, 18 Dec 2009 09:16:21 -0000
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Subject: LF: Re: Re: RE: Noise cancelling by using optic transmission of RX signals
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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 Stöcker" <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 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
> ___________________________________________________________
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>
>
>
>