[ARC5] [MRCA] CW Keying Wheel

[Richard Knoppow]

    I realized that I did not respond to your question of what sort of 
machine this could have come from. I don't know specifically but it was 
likely something like the Omnigraph. See:
<http://www.telegraphkeys.com/pages/omnigraph.html>
    Some additional information on code sending machines can be found at:
<http://w1tp.com/m3500.htm>
    You can trace out the message from the notches. The wheel likely 
worked a switch or contact of some sort. I wrote some detail of how 
these messages were used in my previous post.
    On high frequencies each station had a "beacon" that announced its 
presence and availability. Not used on MF (500 KHZ) or LF. The ITU or 
International Telegraph Union published a directory of all land stations 
and another of all ship stations. The directory listed all frequencies 
used by each station for both calling and receiving. To call a station a 
ship operator would look up the calling frequency for the band of 
interest and call the station. If the beacon was up it meant the station 
was listening for calls on that band. The station would answer the call 
on the beacon and tell the ship to move to its working frequency where 
the traffic was handled. While the frequency was busy the beacon was 
taken off the air unless the station had more than one operator for that 
band. Unlike ham stations, who used a single frequency for 
communicating, ship to shore stations had separate calling and working 
frequencies, all listed in the ITU book.
     I can make out V V V DE on the disc edge but beyond that its in 
shadow and I can't make it out. Should be easy to read if you have the 
actual disc. I also don't know what time period these were used over.

On 8/23/2024 7:48 PM, Gene Smar via ARC5 wrote:
> Found WNU 36 at coastalradio.org.uk . Seems to have been a commercial 
> telegraph station in Slidell, LA and operating on 22431 kHz. My guess is 
> the disc was a mechanical statio ID keyer.
> 
> 73 de
> Gene Smar AD3F


-- 
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998