Mystery Green Mazda valve numbers,

[pwdrive]

With the valve cold I wonder if you could ID the electrodes by stuffing some hum or signal on the heaters and connect the other pins in turn to the input of a valve amp and listen/measure in order to find the cathode, then inject at the cathode and do the rest using the same procedure, thinking of inter electrode capacitance here....Nuts or what...

Lawrence.

[ppppenguin]

Once you've worked out plausible heater current and voltage you'd have to try pretty hard to cause any damage to the valves.

With luck you'll find you have a a large number of 1 or 2 types. That would definitely makes things easier.

[pwdrive]

Re post #21, connect RF to the metalizing, 'scope the pins for anode signal, then RF to one side of the heaters and scope pins for cathode, nearly there then. Or if 'scope = no go (not sensitive enough) connect antenna input of radio to the pins in turn.

Lawrence.

[Herald1360]

If your name was Jackson Pollack or some such, that would be worth millions

I wish!

Playing about with image editing tools can be useful for this sort of problem. Something with a "tunable" colour selection filter would be handy. Tools in basic programs are a bit broad brush, so to speak.