The Y63 'magic eye' tuning indicator is housed in a classic shaped envelope with the electrodes held in a glass pinch. The leads from the pinch are connected to pins in the International Octal base. The triode section is clearly visible in the main picture and requires a grid voltage change of 22 volts for maximum visual change. The display is green.
This is a second generation indicator with a 6.3 volt heater. This type of indicator was used in many radios. This particular exhibit has been masked at the top to enhance visual contrast. It has also suffered a failure of the envelope to base seal and has been repaired with tape.
The classic envelope is 40 mm in diameter and, excluding the IO base pins, is 93 mm tall.
Pin Connections
IO |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |

|
- |
h |
a |
t |
g1 |
- |
h |
k |
Absolute Maximum Operating Conditions |