Transistor BF158 NPN, Video/RF TO-72
Transistor BF158 NPN, Video/RF TO-72
Transistor BF158 NPN, Video/RF TO-72
Transistor BF158 NPN, Video/RF TO-72

Transistor BF158 NPN, Video/RF TO-72

Transistors
TRBF158
Part.No: BF158
€1.00
In Stock
Immediate Dispatch

The BF158 is a high-frequency NPN BJT transistor in a shielded TO-72 package, purpose-built for wideband video and RF amplification. Originally designed for television IF (Intermediate Frequency) amplifier stages, it remains a classic choice for vintage electronics restoration and RF applications.

 

BF158 NPN Transistor – High-Frequency Video & RF Amplifier for TV IF Stages

The BF158 is a specialized NPN transistor engineered for wideband video and RF amplification. With its shielded TO-72 metal can package, it was the standard choice for television intermediate frequency (IF) amplifier stages in black-and-white and early color CRT televisions. The fourth lead grounds the shielding, effectively suppressing unwanted coupling and maintaining signal purity in sensitive RF circuits.

Functions & Applications

  • Wideband RF Performance: Optimized for video and intermediate frequency (IF) amplification with excellent high-frequency response.
  • Shielded TO-72 Package: Four-lead metal can design with integrated Faraday shield (4th lead grounds the can) to minimize RF interference and cross-coupling.
  • Vintage Television Heritage: The preferred choice for restoring classic black-and-white and early color CRT television tuner and IF amplifier sections.
  • Low-Noise Design: Suitable for sensitive RF and video signal processing applications requiring minimal phase distortion.

Technical Specifications

ParameterValue / Specification
Transistor TypeBJT (Bipolar Junction Transistor)
Polarity / ChannelNPN
Package / CaseTO-72
Transistor TypeNPN BJT
PackageTO-72 (Shielded Metal Can, 4-pin)
Primary ApplicationVideo IF Amplifier, RF Amplification
Mounting TypeThrough-Hole (THT)

Frequently Asked Questions

Q: What makes the BF158 different from other NPN transistors like the BC547?
A: The BF158 is specifically optimized for high-frequency and wideband RF applications with superior noise characteristics and shielding. The BC547 is a general-purpose small-signal transistor. The BF158's metal can TO-72 package with an integrated shield makes it ideal for video/IF circuits; the BC547's TO-92 plastic package is better for low-frequency switching and audio.

Q: Can I use the BF158 as a direct replacement for a failed transistor in a vintage TV?
A: Yes, the BF158 is a classic replacement for IF amplifier stages in black-and-white and early color televisions. However, always verify the pin configuration and check the schematic, as some vintage designs may have slightly different biasing. The shielded can must be properly grounded to the chassis for optimal performance.

Notes

The BF158 is a vintage RF transistor, now largely superseded by modern MOSFETs and integrated amplifiers, but remains valuable for restoring classic television equipment and RF experiments. Availability may be limited; prioritize NOS (New Old Stock) or tested used units from reputable vintage electronics suppliers.

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
NPN
Transistor Case Style
TO-72
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