Unsual triode configuration

[gsantosk8]

I've studing a SQ decoder for my electrical engineering final term paper and I'm looking for a tube configuration that is analogue to this circuit:

as for the sake of historical contextualization. So, has anyone ever seen a a triode tube operating on this configuration:

An externally hosted image should be here but it was not working when we last tested it.

I've heard that some AM radios might use it, but couldn't fine any example, so, if you know, please, tell me a book or a service manual of a radio that uses it.

 

[ejp]

You have the series resistor and series capacitor in each other's places, if it matters. It's a cathodyne phase splitter, then a differentiator in one phase, then a summing point where the phases cancel above the Ft (of about 200Hz in the transistor version). So, an integrator? Why did you change these R and C values?

 

[DF96]

It is an all-pass filter, used where you want to add some phase shift but no variation in frequency response. About the only place I have seen a circuit like that would be a phasing SSB exciter, although there you might have a whole cascade of such circuits.

 

[PRR]

There was very little excuse to use an All-Pass in days of tubes. Phase is not important enough in audio to spend bottles.

The shining example would be MagnaTone vibrato, in which the fixed resistor is made variable.
https://www.magnatoneamps.com/schematics/magnatone_410.pdf
https://www.magnatoneamps.com/schematics/magnatone_280a.pdf
MagnatoneAmps.com

 

[gsantosk8]

Thank you all, just found out the name of such circuit, it's called Moses' phase shifter. If anyone ever come across this Moses guy, if he's still alive, tell him I'm very thankful.

https://dalmura.com.au/static/Magnatone vibrato design.pdf

 

[DF96]

I doubt if Mr. Moses invented the circuit, and I have never heard it called a Moses phase shifter. He invented an application for a particular version of it. As I said, it is known as an all-pass filter.

 

[Osvaldo de Banfield]

All pass filters are used to create oscillators, I saw anywhere in the net.

 

[gsantosk8]

I doubt if Mr. Moses invented the circuit, and I have never heard it called a Moses phase shifter.

I'm not sure either, I just read the article I posted and it says it's called Moses's phase shift. The point is, all the proffessors who are gonna grade my final paper term ain't much worried about worried about historical accuracy as long as I cite an article as a source, I mean, in case it's wrong, blame whoever wrote it. I truly wish I could find a more reliable source of who 1st invented such circuit, but it's been hard as hell and the only thing I got is this article.

 

[PRR]

I doubt if Mr. Moses invented the circuit, and I have never heard it called a Moses phase shifter. He invented an application for a particular version of it. As I said, it is known as an all-pass filter.

The passive R-C phase shifter is known from before WWII (sorry I don't have a cite).

I don't recall seeing the cathodyne-driven phase shifter before the 1950s (when Moses wrote); he may have been early in documenting this technique.

It's not in RDH, Shea's fat Amplifier Handbook, or Turner's slim Waveform Measurements.

And Moses 1953 is a fine cite for school-work.

 

[trobbins]

Yeh, cite the original Moses doc rather than my article - I may get a D- rather than a B+.

Moses used the circuit in a measurement technique - so it was the application of the circuit.

And I think you reached a bit far to say "its called Moses's phase shift" - that was just a brief description for the circuit snip presented in a figure.

Ciao, Tim

PS. you will get an A+ if you can work through the phase shift to be expected from that circuit for particular part values.

 

[gsantosk8]

Yeh, cite the original Moses doc rather than my article - I may get a D- rather than a B+.

Oh, there you are, the writer, thanks for writting such article, guess I misinterpreted when you wrote Moses' phase shift. And, didn't mean to offend you by sayind "blame whoever wrote it", after all it was my mistake, and, as I'm gonna be graded by engineers, some of them might not even care about historical contextualization, all they care is about derivatives, integrals, current and voltage calculations., proof of concepts...

 

[trobbins]

I hope you get a B+ (as well as the pun )

 

[gsantosk8]

I hope you get a B+ (as well as the pun )

Let's hope for it, and, as soon as I finish my transistor based SQ decoder, I'll try to design a tube version of it. Not just the phaser itself, but the logic circuitry as well, tubes solving audio equations in real time.