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AF114 Transistor Data

Key transistor data for the AF114 germanium PNP high frequency (for its day) transistor including key electrical parameters, pinout, package type and many other key transistor datasheet details.

The AF114 was an RF transistor used in many radios and other applications where higher frequencies were needed. It's performance by today's stadards is relatively poor, but in its day it offered a good level of performance

The AF114 is part of a series of transistors, AF114 - 117, which all appear to have very similar levels of performance.

Key details and performance parameters for the AF114 transistor.

Transistor datasheet parameters & data
Parameters	Details
Transistor type	PNP germanium transistor
Package type	TO7
V_CBO max (V)	32
V_CEO max (V)	15
V_EBOmax (V)	2
I_C max (mA)	10
T_J Max °C	75
P_TOT mW	75
f_T min (MHz)	75
C_OB	3p
h_fe	50 min
I_C for h_fe	1 mA
Similar / equivalents	AF124

Outline:

Pinout:

Explanation of transistor parameters

Parameter	Explanation
V_CBO Max	Maximum collector-base voltage with emitter open circuit .
V_CEO Max	Maximum collector-emitter voltage with base open circuit.
V_EBO Max	Maximum emitter-base voltage with collector open circuit.
V_CEsat (included where applicable)	The voltage drop across the collector-emitter when the transistor is fully saturated (acting as a closed switch).
I_C Max	Maximum collector current.

Parameter	Explanation
T_J	Maximum junction temperature.
P_TOT Max	Maximum device dissipation normally in free air at 25°C unless other conditions indicated.
f_T Min	Minimum cutoff frequency at which the current gain in a common emitter circuit falls to unity.
C_OB Max	Maximum collector capacitane, normally measured with emitter open circuit.
h_FE	DC current gain for H_FE at I_C. [Note hfe is the small signal gain and although this may be slightly different, the transistor current gain will vary considerably from ne transistor to the next of the same type.]
P_TOT Max	Maximum device dissipation normally in free air at 25°C unless other conditions indicated.

These are the main transistor parameters that have been included in our list. There are others, but these help quantify the main elements of the performance of the transistor.

Read more about . . . . Transistor Data-sheet Specifications & Parameters.

Please note, that the data given is the best estimate we can give within a tabulated summary of this nature. Parameters also vary between manufacturers. Electronics Notes cannot accept any responsibility for errors, inaccuracies, etc, although we do endevaour to ensure the data is as accurate as possible.

Notes and supplementary information

• Performance and specification

The AF114 was one of a series of alloy diffused germanium transistors manufactured by Philips / Mullard in the 1960s, and some examples of devices manufactured by Siemens can also be found.

The AF114 was described as a PNP germanium diffusion alloy transistor intended for use as an FM pre-stage amplifier.

• Reliability

The AF114 like others in the series suffered greatly from a poor level of long term reliability. They are a common cause of failure in many vintage transistor radio sets.

The reason for this is that they tend to develop internal short-circuits between the can / screen and either the collector or emitter. Sometimes it might be possible to pass a current through the short circuit to blow the short away, but this can be risky and even if it works it should only be considered to be a short term repair.

It appears that the cause is that minute hair-like conductive zinc strands grow over time from the zinc based encapsulation and these can cause short circuits within the encapsulation of the device.

Replacement with the later AF121, 124, 125 etc can be a way forward, but these types have long ceased production and they are difficult to obtain, and also not as reliable as modern devices.