Wikipedia has an entry for Tuned RF receivers that says EH Armstrong
invented the Tuned RF receiver in 1918. I think this is wrong. Armstrong
was in the throes of patenting the superheterodyne circuit at that time.

Hazeltine invented the Neutrodyne, but this was an improvement on the TRF
circuit. Was it just one of those things that logically developed from
wanting a bigger signal for the detector?

73,

Tom

I have a copy of "The Electrical Review" from 1902 wherein
Signor Marconi is describing his experiments with "syntonising",
a means by which the station at Poldhu no longer interferes
with the station on the Lizard. It was clear from the article
(although I have not referred to it for several years) that he
is referring to tuned circuits.

We take many things for granted nowadays, but even the
concept of tuning was the subject of a patent in them thar days.

"Thomas H. Busch" wrote in message
...
Wikipedia has an entry for Tuned RF receivers that says EH Armstrong
invented the Tuned RF receiver in 1918. I think this is wrong. Armstrong
was in the throes of patenting the superheterodyne circuit at that time.

Hazeltine invented the Neutrodyne, but this was an improvement on the TRF
circuit. Was it just one of those things that logically developed from
wanting a bigger signal for the detector?

Hi,
Ernst Alexanderson of GE held the controlling TRF patent, on the
principle of inserting tuned circuits between successive gain stages.
It was a rather obvious concept but as just noted, everything was
patentable in those days. Interestingly, Sparton got around
Alexanderson's patent by putting all the tuning at the front end,
feeding a series of untuned RF stages.

Wikipedia is wrong. Howard Armstrong was indeed working on the
superheterodyne in 1918:

http://antiqueradios.com/superhet/

(loading is apt to be slow, since the server also handles an active
antique-radio forum).

73, Alan

Alan Douglas wrote:


Wikipedia is wrong. Howard Armstrong was indeed working on the
superheterodyne in 1918:

Wilkipedia usually is wrong. Its compiled with 'user' input. You could
submit that YOU were the inventor!

-Bill

Wasn't it Nikola Tesla who invented or discovered the basic concepts of
tuned circuits?

Doug


"Airy R.Bean" wrote in message
...
I have a copy of "The Electrical Review" from 1902 wherein
Signor Marconi is describing his experiments with "syntonising",
a means by which the station at Poldhu no longer interferes
with the station on the Lizard. It was clear from the article
(although I have not referred to it for several years) that he
is referring to tuned circuits.

We take many things for granted nowadays, but even the
concept of tuning was the subject of a patent in them thar days.

"Thomas H. Busch" wrote in message
...
Wikipedia has an entry for Tuned RF receivers that says EH Armstrong
invented the Tuned RF receiver in 1918. I think this is wrong.
Armstrong
was in the throes of patenting the superheterodyne circuit at that time.

Hazeltine invented the Neutrodyne, but this was an improvement on the TRF
circuit. Was it just one of those things that logically developed from
wanting a bigger signal for the detector?

DOUGLAS LOSTY wrote:

Wasn't it Nikola Tesla who invented or discovered the basic concepts of
tuned circuits?

Doug

Therein lies the 'rub'. Tesla was busy inventing them while other
people were putting them into actual use.

-BM

DOUGLAS LOSTY wrote:
Wasn't it Nikola Tesla who invented or discovered the basic concepts of
tuned circuits?

Sort of. He noticed resonance effects, but he never figured out how to
apply mathematics to describe them or predict them.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Braun? Yours must count as a coherent reply!

"Edmund H. Ramm" wrote in message
...
In . net "DOUGLAS LOSTY"
writes:
Wasn't it Nikola Tesla who invented or discovered the basic concepts of
tuned circuits?
Ferdinand Braun did. That's why he and Marconi received the Nobel Prize
together.

In article , Alan Douglas
adouglasatgis.net writes:

Interestingly, Sparton got around
Alexanderson's patent by putting all the tuning at the front end,
feeding a series of untuned RF stages.

I restored one of those Sparton radios, and it works very well -- every bit as
selective as any other 4-stage TRF AM-BC set of the time.

I also have a spare tuned front end from that project, which I keep intending
to use as a "secret weapon" preselector ahead of a modern AM rx for BC DXing.
--Mike K.
..
Oscar loves trash, but hates Spam! Delete him to reply to me.

In article , (Scott Dorsey)
writes:

Wasn't it Nikola Tesla who invented or discovered the basic concepts of
tuned circuits?

Sort of. He noticed resonance effects, but he never figured out how to
apply mathematics to describe them or predict them.

ISTR that Tesla invented the notion of tuning an RF transformer by adding a
third winding and tuning that to resonance, rather than try to tune the very
low-impedance primary (a half dozen turns) or the high-voltage secondary of his
Tesla Coils.

I *suspect* that some Grundig tube radios get their selectivity and sensitivity
out of hardly any stages, by using tertiary resonant windings a la Tesla in
their IF transformers, along with the usual tuning of primary and secondary.
--Mike K.

Oscar loves trash, but hates Spam! Delete him to reply to me.