Measuring winding capacitance on a transformer is tricky as well.
Does your meter provide C-measurement at 10kHz and 100kHz?
Does our meter display phase angle?
Does your meter provide C-measurement at 10kHz and 100kHz?
Does our meter display phase angle?
No, as transformer loading is different.
For frequency response the OT should be loaded with the designated secondary load.
This effectively damps the primary resonance.
With the LCR meter there's no loading, so resonance fully develops.
OK guys, measured self-capacitance of the primeries, 1300pF and 960pF. 1300pF is the one with 10H at 1kHz, 960pF is for 20H at 1kHz.
That might kind of explain something, if the LCR is seeing a resonance.
Thank you,
Andre
That might kind of explain something, if the LCR is seeing a resonance.
Thank you,
Andre
The culprit could also difference in core properties. If the LCR picks up the main L with parasitic Cp+Cs resonance, main L could vary if for some (BAD) reason the core isn't exactly the same.
P.S. Looks like you, at least partially solved the issue. Quite a huge difference in capacitance, IMHO.
P.S. Looks like you, at least partially solved the issue. Quite a huge difference in capacitance, IMHO.
50AE, the fenomena follows the coil (bobbin), I tryed to swap the iron twice, same results.
The interwide capacitance of the primeries different, conciderable, but not huge, though might have an effect.
I just thought, it could be that I have used different paper type between the layers. One of cashier register, the other of brown packing paper, though the same thickness.
Highly possible, yes. Paper varies in density, hardness, all can result in difference of dielectric constant. You should always test your dielectrics before applying them to an audio transformer. pH water test, capacitance test between two plates and dielectric breakdown test, if to be used between high voltage potentials.