Pyrazo Device

[turbo]

I don't know much about tubes, but don't the electrons flow from the element with the heater?

Should be able to substitute field effect transistors for the tubes?

Yes the electrons are boiled of the hot filament similar to steam evaporating from boiling water.

In tubes there is covection transmission at work which is energy flow inside the tube that is not bound to a conductor.
In transistors there is conventional transmission at work which is bound to conductor.

That means there is a diffrence,but it does not mean both elements can't perform similar functions.

Needles to say,tubes block the flow in one direction completly, where Solid State devices only conduct better in one way then the other...which means that they conduct in both directions just not in an equal value.

Marco.

[jadaro2600]

Yes the electrons are boiled of the hot filament similar to steam evaporating from boiling water.

In tubes there is covection transmission at work which is energy flow inside the tube that is not bound to a conductor.
In transistors there is conventional transmission at work which is bound to conductor.

That means there is a diffrence,but it does not mean both elements can't perform similar functions.

Needles to say,tubes block the flow in one direction completly, where Solid State devices only conduct better in one way then the other...which means that they conduct in both directions just not in an equal value.

Marco.

This is true, I think however that one drawback to their use it the necessity of heat, which ultimately results in waste.  He does have a transistor based diagram at the bottom, I'm at a lack as to how it incorporates though.  It's a very nice animation, btw. very well thought out.

[CompuTutor]

Tubes are the best for this, period.
Transistor's are right out of the equation here.

field effect transistors's would work
if you used the insulated gate variety,
but why mess up a good thing like this?

There are just some things that tubes will always be better for.

They by the very nature of their design work well
in circuits like this where thier natural tendancy for
even harmonics are key to It's proper operation.

Transistors tend to introduce odd harmonics,
and have their place in circuitry where the cancelling
of even harmonics is desirable for proper operation.

And yes, the heater heats the center cathode,
which is what it flows from.

the outer (HV) plate is where it flows to.

But in this circuit, it is the high Z of the grids
that make insulated gate fet's the only option.

Hope this helps people.

[CompuTutor]

I guess my real question is what's turning on the base of the transistors -- unless they're tied to the collectors and ground via some biasing resistors. 

Chris

Look at the first top picture on that page.
Note the light purple (Lavender?) area upper left.
See the transformer being used as a detector?
More of a current sensing shunt detector really.

Those four letters feed the bases,
just line up the letters respectively.

in the third entry of that transistor analogy flowchart,
you'll see what would be what the fet's would do.

But placing the final transformer across the center of a bridge
made up of four tubes/fet's would provide more output
due to the common mode aspect of the resonance.

This ciruit will work without the heaters in many case,
but better with heaters to help with cathode emission.

Very novel use of resonance in a cold cathode circuit.

The key to the first pic is a longwire antenna
appropriate to creating a resonant standing wave.

Like every good antenna/receiver.
It takes a note,
to hear a note.