▼ Menu

HF

 
See also:
Mullard HF, LF, WECO, ORA & DF.ORA Advert - Mullard HF & LF Advert - Mullard HF & LF Advert
    
Extras ▼

 

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: 1003. Type HF was first introduced in 1924.

 

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
Updated January 23, 2013.
Return to Main Index