Transistor AF109 PNP, Germanium RF TO-72

Transistor AF109 PNP, Germanium RF TO-72

Transistor AF109 PNP, Germanium RF TO-72

Transistor AF109 PNP, Germanium RF TO-72

Transistor AF109 PNP, Germanium RF TO-72

Transistors

Reference: TRAF109

Part.No: AF109

€1.40

In Stock

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The AF109 is a PNP Germanium BJT in a TO-72 package with 4 leads including shield. Purpose-built for RF and high-frequency amplification stages with excellent low-noise characteristics, ideal for restoring vintage radio receivers and RF circuits.

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Description
Product Details

AF109 Germanium PNP Transistor - Shielded RF Amplifier for Vintage Radio Restoration

The AF109 is a rare, high-performance PNP germanium transistor designed specifically for RF amplification and low-noise applications in vintage radio circuits. Its 4-lead TO-72 package includes an integral shield connection, providing exceptional electromagnetic interference rejection—a critical feature for stable operation in sensitive RF stages.

Functions & Applications

4-Lead Shielded Package: Integrated shield connection drastically reduces RF interference and provides stable performance in high-frequency circuits.
Germanium Construction: Excellent low-noise characteristics and natural soft-knee saturation behavior ideal for linear RF amplification.
PNP Polarity: Enables direct compatibility with complementary NPN stages (AF108) in push-pull and driver configurations.
Vintage Radio Ready: Purpose-designed replacement for original AF109 positions in classic tube and solid-state radio receivers.

Technical Specifications

Parameter	Value / Specification
Transistor Type	BJT (Bipolar Junction Transistor)
Polarity / Channel	PNP
Package / Case	TO-72
Transistor Type	Germanium BJT (PNP)
Package	TO-72 (4 leads with shield)
Mounting Type	Through-Hole (THT)
Application	RF Amplification, Low-Noise Stages

Frequently Asked Questions

Q: How do I identify and connect the shield lead on the AF109?
A: The shield lead is typically spaced further from the three main leads (collector, base, emitter) or marked by a metal tab on the case. Connect it to ground or to the RF stage shielding to minimize interference.

Q: What is the complementary NPN transistor to pair with the AF109?
A: The AF108 is the complementary NPN germanium transistor, designed for direct pairing in push-pull and complementary amplifier stages.

Notes

Germanium part (NOS/vintage stock). AF109 is a rare, purpose-designed RF component; verify pin configuration and shield grounding in your specific application. May require slight bias circuit adjustment compared to modern silicon equivalents due to lower Vbe drop (~0.2V vs 0.65V).

Note: Price refers to one (1) piece. The component is shipped in bulk without individual packaging.

Transistor Type: BJT (Bipolar Junction Transistor)
Transistor Polarity / Channel: PNP
Transistor Case Style: TO-72

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