(Len Over 21) wrote in message ...

Your son must still think it is possible to voice-modulate a SPARK
transmitter. Pity that, considering he is a (self-stated) "degreed-
before-USN-service Master Chief" now a Manager at an electronics
company.

Voice modulating a spark transmitter would be like trying to voice
modulate a doorbell buzzer. It creates something that may sound
like voice but it sure isn't intelligible. You should encourage him to
work on the techniique. It might even make an interesting project to
highlight the tube fanzine called "Electric Radio!"

For those interested in facts rather than Len's usual infantile
nonsense and bluster, here are some insights into how Fessenden did
it:



Sound of a voice modulated spark transmitter:

http://www.eht.com/oldradio/history/...e/Fess-voc.htm

Noisy but intelligible. Not at all like a doorbell buzzer. Mr.
Thiessen was able to understand the message well enough to telegraph
back that it was, indeed, snowing where he was.



Sounds of various types of spark transmitters, including the above:

http://www.acmi.net.au/AIC/SPARK_SOUNDS.html

The 3 phase sync gap sounds almost like CW.



Historical writeup (with references) of Fessenden's developments and
accomplishments in early wireless:

http://ewh.ieee.org/reg/7/millennium...fferences.html

Note that this link is to (ahem) an IEEE page. They seem convinced.



Short and incomplete list of Fessenden firsts in radio:

- First voice and music transmissions by radio
- First 2 way transatlantic radio contact of any type
- First transatlantic voice transmissions
- First 2 way transatlantic radio contact using voice
- First broadcast of voice and music (both live and recorded music)
- Inventor of heterodyne method of reception for undamped waves

(with over 500 patents, a complete list of Fessenden firsts takes a
bit of compilation...)

Fessenden beat Marconi to practical 2 way transatlantic radio even
though Marconi had first demonstrated 1 way transatlantic radio.
Fessenden also had a working 2 way transatlantic *voice* radio link
less than 5 years after Marconi's claimed reception of the letter "S".

But don't take my word for it. See the links.