Half power switch

[Bruciep07]

Can someone help me understand the 100W/50W switch on #124? Just looks like it switches the cathode on a tube from each side from ground(100W) to a 10K resister through an led to ground(50W)... So it is limiting the current but not completely shutting it off? What about impedance matching (insert kicking dead horse quote here) with 2 tubes "turned off"... I just can't wrap my head around this for some reason...

[Funkalicousgroove]

they are still in circuit, just bareley operating so no need to change impedance

[Bruciep07]

Thanks for the reply, that makes sense to me... So if you wanted to add bias check resistors off of the cathode, you would just need to put them in line with the switch. It makes sense to me now...

[Funkalicousgroove]

Yeah, just check it when youare in full power mode, otherwise it will read hot with a DMM