The Mazda HL42DD (HL42/DD) is a mains operated double diode variable μ triode for use in radio receivers. The data-sheet states that the diodes are screened from the triode.
The reverse is plain zinc loaded paint.The classic envelope is 33 mm in diameter and, excluding the MO base pins, is 89 mm tall.References: Data-sheet & Data. Type HL42DD was first introduced in 1939. See also 1939 adverts. |
Pin Connections
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | tc |  h | k | a | nc | a(d2) | s | a(d1) | h | g1 |
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Absolute Maximum Operating Conditions¶
| Vh | Ah | Va | Vg | mAa | ra | gm | μ | 
| 4.0 | 0.65 | 250 | -1.25 | 1.75 | 8,000 | 2.9 | 23 |
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Updated June 09, 2024.
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