Message-ID: <4E90BD44.1060700@telus.net>
Date: Sat, 08 Oct 2011 14:14:44 -0700
From: Scott Tilley <sthed475@telus.net>
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References: <4E9083DB.5090603@iup.uni-heidelberg.de> <4E909FCE.7060302@telus.net> <4E90A3F1.8080004@iup.uni-heidelberg.de>
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Subject: Re: LF: Laser link...
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Hi Stefan

I've created a wide-band audio link before using a laser.  In fact, I 
used it to bounce the audio I wanted to send off of a passive 
reflector.  Wideband and excellent fidelity is possible, just ensure the 
object you are bouncing off is very stable otherwise you'll get 
microphonics (useful if you want to hear what's going on somewhere else 
:-)........  I strongly recommend the use of a very narrow band 
interference type filter for the laser wavelength you are using, mount 
this over the PIN diode detector...  This way the system is usable day 
or night without noticeable degradation due to sunlight.

73 Scott


On 10/8/2011 12:26 PM, Stefan Schäfer wrote:
> Thanks Dex and Scott,
>
> Enough stuff to study now. The seconds page seems more useful for me.
> Ok about that OT.
>
> 73, Stefan
>
> Am 08.10.2011 21:09, schrieb Scott Tilley:
>> Hi Stefan
>>
>> http://www.k3pgp.org/laser.htm
>>
>> I use his detector and modulator circuits for my system.
>>
>> 73 Scott
>>
>>
>>
>>
>> On 10/8/2011 10:09 AM, Stefan Schäfer wrote:
>>> LF,
>>>
>>> Just thought about trying a LF RX in the forest and feed the signal 
>>> via a laser link to the building here. There is a good direct view 
>>> to several suitable places, a good 1000m distant from the city. A 
>>> simple laser diode, driven at 15 to 20 mA should work fine for some 
>>> hours when having a solar panel that charges during the day. You 
>>> know these small lamps for the garden with a solar panel, switching 
>>> on automatically when it gets dark...
>>> Just seen HA6PC at OE3GHB-grabber but nothing here or at DF6NM (yes 
>>> Mal, i know, you've all worked them in the past...).
>>> Pure AM is probably not the best choice, rather FM.
>>> Does someone of you has useful experiance of such a laser system or 
>>> even a ready to use circuit or some hints about a compact IC that 
>>> does the job?
>>>
>>> No warnings about the danger of laser light please.
>>>
>>> 73, Stefan/DK7FC
>>>
>>> PS: Sri for beeing a bit OT
>>>
>>>
>>
>
>