[VHFcontesting] [VHF] Optical transverters [was: Time to Change VUCC Rules?]

[Les Rayburn]

Ev & The Group,

Most of the discussion related to the transverter design has taken place on the “Laser” list devoted to free space optical communications at QTH.net. The design is the work of Stuart Wisher, G8CYW. You can see a copy of the schematic at 
this link: 

http://www.aladal.net/toast/detector.html 


Stuart’s design uses a single high power LED for both the transmit and receive path, which significantly reduces the difficulty in “aiming” towards the distant station. This is no small point, especially at DX distances. It also includes TX/RX relay switching, and is suitable for use with a small IF rig like the FT-817ND or FlexRadio 1500. 

Many of us believe that a “transverter” design for optical communications, especially using a single LED could greatly increase the popularity of optical communications. 

This is also a great choice for rovers, and fixed stations wishing to “add a band” during contests without spending a lot of money. Simple optical communications can be added for well under $200. I’m kind of surprised that the “pack rovers” in California didn’t make this band one of their first choices. 

Stuart’s QRZ.com entry tells more—and he’s very active on the “Laser” list.


My big passion these days is optical communication and I have designed and constructed several rigs for AM and FM using lasers and power LEDs.  The current state of the art is an optical transverter that enables the FT817 to be converted from 80m to light, including sideband - I think this is a world first.  I operate within a small group of like-minded radio amateurs (Northern Lights Optical Communications Group) where we are interested in microphone to loudspeaker immediate communications, rather than computer-based data signals.  Our current distance record is 32km (20 miles) on AM, and 6km on SSB, although this was not difficult since signals were end-stopping.  Watch this space for future developments! UPDATE last week I made SSB QSOs at 34km with G8KPD (20.9.10) signals 58 both ways, and 32.8km with GPNN (21.9.10) signals again 58 both ways. I also received FM from Gordon that end stopped the RX.  We will be testing over a 46km path when the weather allows.




From: Ev Tupis 
Sent: Tuesday, November 23, 2010 4:55 AM
To: VHF Contesting Reflector ; vhf at w6yx.stanford.edu 
Subject: [VHF] Optical transverters [was: Time to Change VUCC Rules?]

----- Original Message ----

> A  handful of amateurs are currently working to develop optical
> btransvertersb  that would work with IF rigs like the FT-817 and others on
> full-fledged  transceivers that utilize one LED as both emitter and detector,
> which greatly  simplifies mechanical design and aiming.
---------------------------

Les,
A quickie Google search for the term "optical transverter" yielded not much of 
use.  Care to share more information on the topic?
Ev, W2EV
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