New Dumblelator build question

[akabek]

This is my first go at building a Dumblelator using a prefabricated PCB board. I am at the stage or wiring everything up. My apologies if my questions are basic. What size/gauge wire should I use?

On hand I have 22AWG, 24AWG 300v and 20AWG 600v stranded wire. I also have 22AWG 2 conductor 600v shield wire.

The schematic I am working from shows a shield cable with a positive and negative connected to the drive pot connection 1 and 2 but on the send jack there is only a positive connection. Is this correct? If so for the ground connection if I am using a 2 conductor wire for the ground should I use the black or silver shielding wire?

20240201_083805.jpg

Dumblelator schematic A.jpg

[dbharris]

I would use the 600v stranded for the high voltage runs. The 22 awg stranded should be fine for the rest that is not shielded. But I prefer 600v solid core so that it stays put.

For the shielded wire, just use one conductor and the outside mesh shield. You may want to make a test piece that is 1 foot long and measure the capacitance to see where it lands.

The ground scheme is important. You should study the layout in the files section here so you don't accidentally create a ground loop.

-Dan

[akabek]

Thanks for the response Dan.

For the shielded wire connections is it correct to connect the outside mesh shield on one end but not the other? In my schematic it has the shielded cable running from drive pot to the send jack but the mesh shield is only connected to the pot. I will check the capacitance of my shielded cable.

I would prefer to use solid core wire as well. The stranded wire I have is very flexible so it will not hold position for a clean install. I will see what I can find.

[Stephen1966]

For the shielded wire connections is it correct to connect the outside mesh shield on one end but not the other?

Yes.

Heat resistant shielded cable with low capacitance is good: https://www.tube-town.net/ttstore/en/co ... 7-1-m.html

The black and the white wires you have are signal wires, the ground is the bare stranded and the foil/mesh around the outside. I wouldn't bother with it, more likely to cause problems than solve them.