HF @ The Valve Museum

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HF

See also:

Mullard HF, LF, WECO, ORA & DF.ORA Advert - Mullard HF & LF Advert - Mullard HF & LF Advert

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Mullard The John Lawrence Collection Other HF exhibits

The HF red ring was introduced by Mullard in 1924 as an RF amplifier or detector. The red ring around the top of the envelope. Mullard also made an LF for audio use and externally the difference is a green ring around the top of the LF.

The balloon envelope is 38 mm in diameter and, excluding the B4 base pins, is 85 mm tall.

Reference: Data-sheet & ¹⁰⁰³. Type HF was first introduced in 1924. See also 1924 adverts.

Pin Connections

B4	1	2	3	4
	a	g1	f	f

Absolute Maximum Operating Conditions^¶

Triode	Vh	Ah	Va	Vg	mAa	ra	gm	μ
	4.0	0.6	90	-	-	40,000	0.24	9.8

PDF scanned from an original document held by the museum

Updated September 04, 2018.

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