Negative feedback problem Help

[g1]

Just in case it's an issue, are you using an old version or new version of the OT wiring? The secondary of the older ones is not quite simple.

[catalin gramada]

That doesn't make sense. Output phase should invert.



Please see post #27.

For sure it revert but still remains out of phase. The only thing it put in phase is reversing the ot output taps.

[Helmholtz]

Just in case it's an issue, are you using an old version or new version of the OT wiring? The secondary of the older ones is not quite simple.

What is the old version?

[catalin gramada]

Just in case it's an issue, are you using an old version or new version of the OT wiring? The secondary of the older ones is not quite simple.

Is a new version. Easy wire version. But get the pdf info it shows clearly how the OT is winded. For a reason they started the primary and secondary from opposite direction

[catalin gramada]

What is the old version?

The old one is 1650W. Mine is 1650 WA

[Helmholtz]

Scoping a floating OT secondary makes no sense, gives unpredictable results. Scope signals always refer to ground.
And of course the NFB signal needs a ground reference too.

[catalin gramada]

Still don't get it. What ot tap for this OT should be grounded please ?

[Helmholtz]

Still don't get it. What ot tap for this OT should be grounded please ?

You should ground the 0 Ohm secondary wire as shown in the OT specs and repeat the scope measurements and tests. If output and input are out-of-phase, reverse the OT primary wiring.

[catalin gramada]

1650WA

[catalin gramada]

You should ground the 0 Ohm secondary wire as shown in the OT specs and repeat the scope measurements and tests. If output and input are out-of-phase, reverse the OT primary wiring.

This is something already did: with black common wire at ground and reversing PI phase did not do any difference regard in phase/out of phase. In both circumstances the in and out signals was out of phase. The only thing I tried and put the output signal with input signal in phase was to reverse the common and 8 ohm output taps.

[Helmholtz]

This is something already did: with black common wire at ground and reversing PI phase did not do any difference: The signals are out of phase. The only thing I tried and put the output signal with input signal in phase was to reverse the common and 8 ohm output taps.

Don't tell me that completely reversing the OT primary wiring would not invert the phase of the output signal wrt input signal.
Of course you can't reverse the grid signals at the same time as this would turn the phase back again.

[catalin gramada]

Helm, this is a picture with PI in first instance, OT black common grounded

[catalin gramada]

This is the pic with PI reversed OT black common grounded.

[catalin gramada]

It looks as same. Reversing the PI outputs didn.t put the signals in phase.

[catalin gramada]

And this is a pic with OT output taps reversed : 8 ohm tap to ground and grounded.