Re: Re: Building a 2 Stroke head

[Robin]

[attachment=29]Transformers1.jpg[/attachment]

[attachment=30]Heater1.jpg[/attachment]

[attachment=28]centertap1.jpg[/attachment]
The transformers are in, the power transformer wiring is complete.
Because the PT did not include a center tap for the 6.3v taps, an artificial center tap is added as a ground reference for the heater (filament) circuit and provide hum cancelling. Note the 100 ohm resistors connected between each side of the 6.3v circuit and ground. These 100 ohm resistors were selected from several resistors as a matched pair (99.6 ohms in this case) so that each side of the circuit will balance with the other. It is also possible to substitute a trim pot (220 ohm) between the two 6.3v leads to perfectly balance each side for maximum hum-cancelling.

The fuse and pilot light wiring is messy at this point, these components will have to be removed from the chassis when the front and back panels are attached and the wiring willing be reinstalled more neatly at that time. The panels are in the works.

Note the tightly twisted pair of wires of the heater circuit, this too provides hum cancelling for the circuit.

Next up: Wiring the sockets and pots, and adding components.