The EF184 is a purpose designed high gain frame grid pentode. The EF184 superseded the ubiquitous EF80. The mutual conductance is 15.6 and the closely related (pin compatible) variable μ pentode EF183 has a μ of 12.5.In 1969 Mullard describe the valve as: A frame-grid sharp cut-off pentode for use as an IF amplifier in television receivers. This implies a relatively wide band function at about 33 MHz. The high mutual conductance was important for wide band width amplifiers. Mullard quote operation at 40 MHz.![](../pics/acs0005a.jpg)
The outer screen with the two part anode within. The small active anode plates are formed as one with a strap between them.![](../pics/acs0005b.jpg)
The heater wire is formed from an insulated coil and passes through the cathode as a twisted and inverted hairpin.The thin glass tube envelope is 20 mm in diameter and excluding B9A base pins, is 53 mm tall.References: Data-sheet, 3002 & 1040. Type EF184 was first introduced in 1960. See also 1960 adverts. |