Honeywell Amber Neon Lamp for the F52F. The wire length is 19 inches with individual push-on pin connectors.
We measured the operating voltage at 125 vdc under the load of a working neon light. The no-load voltage with the neon unconnected floated at 740 vdc. Benched tested with a Fluke model 77 DVM and no cells.
On the new series two power supply see the instructions for the 208414 power supply for wiring connections (see schematics on page 3). The earlier Series one power supply connects to P5 and P12. The newer Series two connect to E5 and E6.
If you have a Series two power supply (with the modular connector), use the 4074EYS with the simple modular plug.
NOTE the neon indicator very rarely fails. If your neon light is out, then it is likely there is problem in the power supply or cells.