[Boatanchors] VC radio tube questions

[E C Moxon]

Thumbing through RCA RC-19, see that several pentagrid converters of the
octal and loctal variety had grids no. 3 and 5 as the screens, and so does
the 1L6, on pin 5. A possibility? 
Ed,k1ggi

>In the first stage, the tube appears to be a 1R5, except that a 1R5 has pin
>5
>internally tied to pin 1. In the circuit, pin 5 is tied to a decoupled b+
>through a 15K resistor and a 0.2 MFD bypass capacitor to ground. Does
>anyone
>know of another tube, similar in most respects to a 1R5, but which would
>likely
>use a decoupled B+ to pin 5?