Hello All:
When the Aircraft Radio Corporation built the superhets
we call SCR-274 (or ARC-5) it was all because the British
Admiralty felt the high cost of RDF (etc) was justified.
Read all about it below.
From Wikipedia:
https://en.wikipedia.org/wiki/Superheterodyne_receiver#RDF
"
RDF
There was one role where the regenerative system was not
suitable, even for Morse code sources, and that was the task
of radio direction finding, or RDF."
"The regenerative system was highly non-linear, amplifying
any signal above a certain threshold by a huge amount,
sometimes so large it caused it to turn into a transmitter
(which was the entire concept behind IFF). In RDF, the
strength of the signal is used to determine the location of
the transmitter, so one requires linear amplification to
allow the strength of the original signal, often very weak,
to be accurately measured."
"To address this need, RDF systems of the era used triodes
operating below unity. To get a usable signal from such a
system, tens or even hundreds of triodes had to be used,
connected together anode-to-grid. These amplifiers drew
enormous amounts of power and required a team of maintenance
engineers to keep them running. Nevertheless, the strategic
value of direction finding on weak signals was so high that
the British Admiralty felt the high cost was justified."
I found the above when hunting for a little history of the
development of the superhet. My first reaction was to send it
to "our" resident historian (Hue). I admire his extensive
knowledge of radio history and enjoy reading his postings
here. Then I thought others may find the role of the British
Admiralty "interesting" and so I sent it here instead.
I must seek information about the development of the
superhet elsewhere, it seems.
Best 2023 to all
Leslie