help understanding updated DRD from J Elliano's site (using 6AN4 instead of 6n1p)

[jarthel]

here's the schematic: http://www.electra-print.com/images/6AN4_DRD.pdf

I am somewhat confused by the 5K 30W adj. I am assuming it's a pot. but looking at the schematic, it's a pot with 4 leads instead of 3? The 70H choke is connected to the center of the pot and the "other center" is connected to one of outer leads.

in the original drd (http://www.electra-print.com/images/drdamp&ps2.jpg), the pot is a single resistor. The 65H choke is connected after the resistor. and the connections are clearly understood.

can someone explained the connections for the updated DRD?

thank you.

 

[SY]

My guess is that it's not a pot, but a power resistor with two sliding rings. Back in the day, these were made with a rectangular window exposing the wound wires. A ring and clamp were used to make wiper contact. I seem to recall that you could get extra rings/clamps to do extra taps.

 

[Kofi Annan]

SY is right. Jack is a fan of the variable resistor-- I think these are wirewounds in his schematic. In fact, in talking to Jack about the DRD some time ago, he even mentioned that if I ordered the resistors from him, he could throw in a few extra rings to allow for adjustment.

Kofi

 

[jarthel]

My guess is that it's not a pot, but a power resistor with two sliding rings. Back in the day, these were made with a rectangular window exposing the wound wires. A ring and clamp were used to make wiper contact. I seem to recall that you could get extra rings/clamps to do extra taps.

does anyone a readily available substitute for this resistor with sliders? perhaps 2 pots can be used? what values?

thank you for the help