[Milsurplus] WWI Telegraph Set

[Richard Brunner]

That's through-the-ground wireless telegraph.  It's a power buzzer with the 
output connected to two ground rods spaced reasonably far apart.  The ground 
current creates a voltage gradient away from the rods.  The receiving end is 
an amplifier connected to two rods some distance away, which detects the 
voltage gradient and hears the signal.  Note that this is short distance 
communication, probably a few tenth's of a  mile.  It also can be heard by 
the enemy, and probably was not used  for long.  Vacuum tubes were available 
then, so high gain amplifiers were used.

FWIW, the Germans had listening posts all along the front, and could read 
power buzzer, regular telegraph, and telephone communications.  The Allied 
side had them too.

Richard, AA1P


I saw this item on craigslist and figured I'd let the list know about it: 
http://longisland.craigslist.org/clt/4398429654.html I have no connection to 
this sale but figured that someone on the list might be interested in this 
item. I am curious as to how this item would have been used during the war.

Joe Connor