#1 The top plate (grid connection) is 3" square; the hole is 1 and 7/16" diameter.
#2 The PCB (cathode & filament connections) is 2" square; the hole is 5/16" diameter.
#3 The spacing between the top plate and PCB is 1".
#4 The cathode-filament connection is on the top of the PCB.
#5 The grid plate is mounted 5/8 to 7/8" below the chassis, as layout permits. The hole in the chassis is 2.25" diameter.

NOTES:
1. The eight holes used for socket construction are on a 1.125" radius (2.5" squares).
2. Grid contact copper ring diameter: ~ 1.75"
3. Cathode-filament contact copper ring diameter: ~ 1.125"
4. Filament contact copper ring diameter: ~ 0.75"
5. Diameter of copper rings may require "tweaking" to adjust for suitably snug fit on tube contact surface, depending on type of fingerstock used (as close to type shown as possible).

Pictures of these sockets installed in a Drake L-4B conversion project are shown below (Details of the L-4B conversion project will be presented when received):