[MrFixr55]

Hi Arran,

Unfortunately, I can't remember where I read the bonfire bit but I did read it and believed that it came from a reliable source.

I'm sure that you know this but for others following the thread, my RCA 6BT had the option to run off 6V as opposed to 2V / 135V. They had a synchronous vibrator power supply attachment that made the set a "2V / 4V" set where they would use 2V from one cell of the 6V battery for the heaters and 4V from the other 2 cells of the battery. This is because batteries of the era had the straps that connected the cells in series on the top of the battery outside of the case. The 6BT (tombstone) and 6BK (console) cabinets were very similar to other RCA models at the time. These sets were serious performers as they used Class B output stages and good size speakers, 8" for the tabletop and 12" for the console. both were dynamic speakers with substantial permanent magnets (possibly AlNiCo?). The interesting thing is that audio power output for the vibrator supply equipped sets was less than the output of the sets with B batteries. I found that to be interesting.

I, too, have never seen a 2V version of the "Power Shiftr" and don't know if the B voltage was selectable for 90V vs 135V. Seems that many of the Silvertone battery sets with 2V or even 4V filaments used 90V for B+. I suppose that setting the jumper for 6 tubes and replacing the rectifier with silicon diodes may boost the voltage to 2V. Tube current for sets with single end outputs should be similar to the 1.4V tubes. However, for me, this would not be useful until I get my Coranado 650 working, as the RCAs (5BT and 6BT) use 135V for B voltage and I have successfully built a power supply for them.