3.6M north10.pdf - Dean-O's Toy Box

Cathode Pulsers: Hard-Tube Modulators (10) 171
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3-phase healer connections for 6461 triode
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26 in.
32-5/8 in. 1
6461 triode
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10in. ●
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--Li
7560 triade
Figure 10-14. Physical attributes of type 8461 and 7560 power-grid triodes.
tetrode) for a given voltage between anode and cathode;
● and to minim~e the elec~ic-field enhancement at the anode-facing surface
of the grid, which improves the anode-grid voltage-hold-off capability.
The price that must be paid for placing the control grid near the cathode is
increased grid heating due to primary electron interception and the proximity of
the hot cathode itself.
The type 6544 triode was designed especially for modulator switch-tube service,
and it is not a simple triode. Not only does it have a control grid but it has a
shield grid as well. In addition, it has an oxide-coated Unipotentk! (indirectly
heated) cathode of special shape. All of these features, shown in cross-sectional