[NLRS] FYI: Optical QSO

Tue Apr 15 12:46:04 EDT 2025

Those are great ideas Jon. "All" of your equipment is not much of a problem
with the optical equipment ... especially if you are running only one end.
Warren and I often had to set up BOTH ends :-)
Those distances are just right for the next level of testing.
Rob - K0XL

On Tue, Apr 15, 2025 at 11:20 AM Jon Platt via NLRS <nlrs at mailman.qth.net>
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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