Check it out:
https://ei7gl.blogspot.com/2023/12/twice-around-globe-on-21-mhz-and.html
Two trips around is 80,000 km or about 50,000 miles! That's quite a trip. But how about 3 times around? Or more?
Thanks to John EI7GL and to Salvador EA5Y.
Serving the worldwide community of radio-electronic homebrewers. Providing blog support to the SolderSmoke podcast: http://soldersmoke.com
Solar X-rays: Geomagnetic Field: |
Check it out:
https://ei7gl.blogspot.com/2023/12/twice-around-globe-on-21-mhz-and.html
Two trips around is 80,000 km or about 50,000 miles! That's quite a trip. But how about 3 times around? Or more?
Thanks to John EI7GL and to Salvador EA5Y.
The chess device was really interesting, but two things caught my eye about this fellow: 1) he lived and conducted some of his experiments in my old home of Bilbao, Spain and 2) he built a very early radio-control system that used -- in the receiver -- a coherer as the detector.
There is a lot material on Torres Quevedo. Here is just a sample of what is out there
His book: https://www.torresquevedo.org/revistas/index.php/BIB/issue/view/12/1. Discussion of the Telekino device is on pages 109-127.
The Branly Tube or Coherer: https://en.wikipedia.org/wiki/Coherer
https://en.wikipedia.org/wiki/Leonardo_Torres_Quevedo
https://cyberneticzoo.com/wp-content/uploads/2010/12/Telekine-Yuste.pdf
1903 article in Electron (Spain) about the Telekino and Coherers. https://hemerotecadigital.bne.es/hd/viewer?oid=0028654330&page=6
https://alpoma.net/tecob/?p=13766 This article contains the diagram of the device (see above). You can see the coherer with its tapper.
There is a LOT of soul in this new rig. Here is a partial list of contributors:
-- Overall BITX design: Farhan VU2ESE
-- Termination Insensitive Amplifiers (TIA): Wes Hayward W7ZOI and Bob Kopski K3NHI.
-- TIA boards from Todd K7TFC
-- ASK-1 Mixer from Armand WA1UQO
-- VFO design parameters from Joe Carr K4IPV (SK)
-- VFO stability ideas from Frank Harris K0IYE and Mike Murphy WU2D.
-- HT-37 Tuning Capacitor bought from e-bay at suggestion of Pete Juliano N6QW.
-- Pine board base of the rig: Frank Jones (SK) W6AJF's preferred building technique.
-- DTC Band-Pass filter circuits from Han Summers G0UPL.
-- Low pass filter values from G-QRP web site.
-- Idea of using RD06HHT instead of IRF-510 in the final: Pete Juliano
-- Heat sink from Chris KD4PBJ
-- Trifilar Toroids used in many places from Farhan VU2ESE.
Thanks to all. 73 Bill
Background info:
A great report from Daniel Estevez EA4GPZ on radio amateurs receiving telemetry from Chang'e-5: