[NLRS] FYI: Optical QSO

[Mary Brown]

 From Buffalo Ridge near Marshall looking NW to NE there are quite a few 
35+ mile paths... Would need to explore for good spots to work from but 
at around 1900 feet elevation dropping to 1100 where I am you have a 
decent height advantage


Mary

W0AAT

On 4/15/2025 11:20 AM, Jon Platt via NLRS wrote:
> Regarding finding longer line-of-sight paths here in the plains of 
> Minnesota, a few ideas.
>
>   * Kiester, EN33EN03. Southwest of Albert Lea, so not too far away. 
>     Being in southern MN trees are less of a problem then corn.  The
>     Kiester location is essentially tree free in almost all directions
>     and has 12 to 20+ mile horizons.
>   * Monticello EN35CG, the Montiview Mountain Bike Course. Not to far
>     away from Mpls.  Views from west through north thru northeast in
>     the 12 to 15 miles range.  More trees up this way may make finding
>     the other end more difficult.
>   * Darwin, EN25tc.  Darwin Winter Park Area.  Bad news is that its
>     about a 1/4 mile hike from the parking lot, but nice views in most
>     directions.  Would need to lug all your stuff up the hill, but not
>     bad.   There are some 18 mile LOS.  Trees are fewer.  Be a fun
>     spot to do a QRP Hilltop operation from.
>   * EN25VJ72IG south of St. Augusta.  Some views to the east around 16
>     miles
>   * Summit, SD.  EN15lj.  Wilmont Welcome Center.  Some 25 to maybe
>     30+ LOS paths.  Trees are less of a problem unless there a
>     farmstead wind break.
>
>
>
> 73, Jon
> W0ZQ
>
>
>
> On Tuesday, April 15, 2025 at 10:10:11 AM CDT, Rob Jahnke 
> <rcjahnke at gmail.com> wrote:
>
>
> It's great to see some interest in optical communications again.
> Warren (WF0T) and I (Rob - K0XL) made a presentation about our Optical 
> experiments at Aurora 2019. Warren made the same presentation at 
> CSVHFS in July and at MUD in MUD in October of 2019..
> The presentations are available at https://sites.google.com/view/k0xl 
> . Just scroll down past the more recent presentations.
>
> One thing that might be of interest is the modulator which runs on an 
> Arduino ATTiny85. It features an iambic keyer function for CW as well 
> as an audio modulator for voice/music. It also has a beacon mode where 
> the power is stepped down in -3dB steps for signal strength 
> measurements. The schematic and code is available in the appendix section.
>
> I think Warren has exceeded 10 miles (16km) for a QSO. The biggest 
> problem we have in MN/WI is finding long line of site paths. At the 
> end of the presentation, we outlined the possibility of testing a 50 
> km  (32mi) path from Duluth to a Wisconsin Park along the south shore. 
> We also had some ideas about testing "Over the Horizon" paths 
> considering the refraction of light in the atmosphere.
>
> Maybe there will be enough interest to resume some of this activity :-)
>
> See you all at Aurora 2025 June 7th.
> Rob - K0XL
>  .
>
>
> On Tue, Apr 15, 2025 at 12:10 AM Glen Overby <gpoverby at gmail.com> wrote:
>
>     They're using a receiver design by VE2UG, which is based on the
>     one by KA7OEI and K0XL.  Transmit is a PWM generator they bought
>     on Amazon.
>
>     I'm collecting parts for a system.
>
>     73,
>     Glen
>
>     On Mon, Apr 14, 2025 at 11:14 AM Jon Platt via NLRS
>     <nlrs at mailman.qth.net> wrote:
>
>         Some of us through the years have played with optical
>         contacts.  Here is a link to W1VLFs YouTube video discussing
>         and showing his 940 Nm 14 mile QSO.  The QSB and seeing the
>         half power reduction testing is interesting.
>         https://youtu.be/OXYJw9PyHd8
>
>         73, Jon
>         W0ZQ
>
>
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