Wiring diagram of the “synchronous detector” at the receiving station for SAQ?

[Juergen Urbig]

Hallo everybody,
In “The Book of Radio”, Charles William Taussig, 1922, pages 312-327
I found the following technical description of the receiving equipment for SAQ used in Riverhead, Long Island:

“The incoming oscillations are received in circuits corresponding to their respective wave lengths and then, by a complex system of “traps,” are purified of all unwanted signals, including most of the static disturbances. They are then passed through three stages of radio-frequency amplification, then rectified by means of a special two-element vacuum tube which is part of what is called a “synchronous detector”, and finally through two stages of audio-frequency amplification”

Now my question:
Does anybody know the wiring diagram of the “synchronous detector”? You can send either a file or a link to ma my email address
dl4jwu@darc.de.

Many thanks in advance
Juergen (DL4JWU)

Topic

[Jens Romeikat]

Hello,
It’s a bit of speculation, but since it’s built as an RCA system, it should be essentially the same as
the Riverhead receiving system.
At this Forum I have put together what I found.
https://www.wumpus-gollum-forum.de/forum/thread.php?board=29&thread=245&page=1

The most important original sources so far are:
h t t p s://www.crosscountrywireless.net/The%20Wave%20Antenna.pdf
“The Wave Antenna A New Type of Highly Directive Antenna”
(Diagrams of “wave-antenna” / principle circuit of HF-Stages)
h t t p s://ur.booksc.me/book/32038623/02831e
“The Electrical Plant of Transocean Radio Telegraphy”
BY E. F. W. ALEXANDERSON, A. E. REOCH and C. H. TAYLOR

Even more speculation is the detector, 2 interesting patents from Dr. Alexanderson
(just “in time”):
US1535082A ELECTRON DISCHARGE DEVICE
CA208846A SIGNALLING SYSTEM
(“Espacenet-Patent-search”)
In this case a kind of “electronic tone wheel” would have been developed for the receiver.
In any case, one suspects a kind of heterodyne or non-synchronous detector, since a superimposed tone must be generated
that is audible in the headphone.

Jens

[Author]

Replies