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Date: Sat, 08 Oct 2011 23:29:48 +0200
From: =?ISO-8859-15?Q?Stefan_Sch=E4fer?= <Stefan.Schaefer@iup.uni-heidelberg.de>
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Subject: Re: LF: Laser link...
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Thanks again Scott. Yes, the building should be stable ;-) We have a=20
working group here that works with that optical stuff all the time, they=20
surely can give me filters and further advice. They told me they tried a=20
80W ERP laser into the sky, just for fun. Such things can be done on a=20
university, never ever in industry, one reason to work here ;-)

73, Stefan
Am 08.10.2011 23:14, schrieb Scott Tilley:
> Hi Stefan
>
> I've created a wide-band audio link before using a laser.  In fact, I=20
> used it to bounce the audio I wanted to send off of a passive=20
> reflector.  Wideband and excellent fidelity is possible, just ensure=20
> the object you are bouncing off is very stable otherwise you'll get=20
> microphonics (useful if you want to hear what's going on somewhere=20
> else :-)........  I strongly recommend the use of a very narrow band=20
> interference type filter for the laser wavelength you are using, mount=20
> this over the PIN diode detector...  This way the system is usable day=20
> or night without noticeable degradation due to sunlight.
>
> 73 Scott
>
>
> On 10/8/2011 12:26 PM, Stefan Sch=E4fer 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 Sch=E4fer wrote:
>>>> LF,
>>>>
>>>> Just thought about trying a LF RX in the forest and feed the signal=20
>>>> via a laser link to the building here. There is a good direct view=20
>>>> to several suitable places, a good 1000m distant from the city. A=20
>>>> simple laser diode, driven at 15 to 20 mA should work fine for some=20
>>>> hours when having a solar panel that charges during the day. You=20
>>>> know these small lamps for the garden with a solar panel, switching=20
>>>> on automatically when it gets dark...
>>>> Just seen HA6PC at OE3GHB-grabber but nothing here or at DF6NM (yes=20
>>>> 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=20
>>>> even a ready to use circuit or some hints about a compact IC that=20
>>>> does the job?
>>>>
>>>> No warnings about the danger of laser light please.
>>>>
>>>> 73, Stefan/DK7FC
>>>>
>>>> PS: Sri for beeing a bit OT
>>>>
>>>>
>>>
>>
>>
>