Guitar with built in amp and speaker

[Nigel Goodwin]

Originally Posted by razorrick1293

also wondering if a PCF80 would work at a low voltage or a PCC84/88 would work (they have 9v heater filaments)

The 'P' means 300mA series heaters, 300mA is a lot to find for a battery powered device.

The PCC84/88 are 7V heaters, but the PCC85 is 9V (as is the PCF80).

[razorrick1293]

really? i was told the first letter (E/P) corresponded to heater voltage? though thank you for correcting me.

[Nigel Goodwin]

Originally Posted by razorrick1293

really? i was told the first letter (E/P) corresponded to heater voltage? though thank you for correcting me.

It refers to voltage OR current, depending on type.

E is 6.3V, P is 300mA, U is 100mA, D is 0.5V to 1.5V, G is 5.0V

Those are the common ones. also used have been:

A is 4.0V, C is 200mA, and K is 2.0V

Second and subsequent letters describe the valve, C for triode etc.

[benb]

Originally Posted by benb

Google car tube radio. There's a list of "space charge" tubes. That 6GM8 has a max 20mA collector current, ...

I can't believe I wrote that, but "in my defense" (aka my pathetic excuseis ) I read cathode current on an online data sheet, and that's what I wanted my fingers to type.

[Nigel Goodwin]

Originally Posted by benb

I can't believe I wrote that, but "in my defense" (aka my pathetic excuseis ) I read cathode current on an online data sheet, and that's what I wanted my fingers to type.

To be fair, it's one of those things your fingers type on their own

It's so much more common to type 'collector' then 'cathode' it becomes a reflex.