1630 orbital-beam hexode.
 |
The valve measures 55x50mm
overall (25mm across the body) |
This valve was used in early
SCR-270 radar sets as an electron multiplier preamplifier. Due to noise
and reliability issues, it was eventually replaced by a module using 6J4
triodes.
| Anode voltage | 370V |
| Secondary emitter voltage | 240V |
| Outer focusing electrode voltage | 0V |
| Inner focusing electrode voltage | 300V |
| Grid 2 voltage | 45V |
| Grid 1 voltage | -1V |
| Anode current | 12mA |
| Secondary emitter current | 9.5mA |
| Cathode current | 3.5mA |
| Grid 1 to anode transconductance | 15,000 µmhos |
| Input capacitance | 6.5pF |
| Output capacitance | 3.5pF |
Diagram of the 1630 internals. The electrons follow the path marked AA under
the +ve attraction of focusing electrode J1. They then strike the secondary emitter electrode which gives off electrons
at about 5 secondaries for every one primary. These are then attracted to the anode. Varying the potential of focusing electrode J2 causes
the beam to follow the path marked as BB and strike the inner focusing electrode.

|