Whites Surf PI schematic

[nando.22]

to replace the TIP32 by TIP42

[kt315]

SFS9634 p-channel, 250V, 3.4A, 1.8Ohm - SFP9634, 2SJ307, 2SJ308, 2SJ449
2SJ448 NEC Electronics Inc Downgrade Active
FQPF6P25 Fairchild Semiconductor Corp Downgrade Active
FQPF7P20 Fairchild Semiconductor Corp Downgrade Active
SFS9640 Fairchild Semiconductor Corp Downgrade Active
SFS9640 Samsung Electronics Inc Downgrade Active
SFS9644 Fairchild Semiconductor Corp Downgrade Active
SFS9644 Samsung Electronics Inc Downgrade Active
2SJ306 - 2SJ307, 2SJ308, 2SJ449, IRFI9634G, SFS9634, SFP9634

[nando.22]

what goes on in the circuit tp1

[Davor]

tpx is a common notation of "tuning point", e.g. a place where you stick an oscilloscope probe to get more confused

[kt315]

tp - tEST pOINT.

[nando.22]

completed assembly over the sound is very low

[nando.22]

very low sensitivity also

[joop]

Do you have a scope? Did you adjust the offset of the NE5534? You need to give us some more details...

[nando.22]

nao tenho osciloscópio o som esta baixo ouço apenas um zumbino no autofalante quando aproximo um metal na bobina o som desaparece

[homefire]

And what does that mean in English?

[nando.22]

Oscilloscope not have the sound I hear this low only one speaker when the zumbino approach a metal coil sound disappears.

[joop]

Can you post pictures of your coil and PCB?

[nando.22]

characteristics coil 25 cm and 20 turns of 26AWG wire

[nando.22]

ihf9640 by replacing one TIP42

[bernte_one]

That damping resistor might be OK for the coil but the flyback looks like ~70us duration to settle (310us-238us).

Did you have the coil resting near something metallic?

yes i have steel reinforced floor 50cm under coil
thats the common indoor problem i have here

will try it again next weeks in the garden

but thanks for looking

regards