Schematic Diagrams

Useful schematic and wiring diagrams. ✔ ✔ Enjoy electronic circuits, let your idea comes to hardware

500W HF linear amplifier

This is the circuit of a 500 watt linear amplifier, based upon a design by Frits Geerligs, PA0FRI, who has his own homepage at The circuit uses four PL519 TV line output valves in a very simple circuit that will deliver over 450 watts at 3.5 MHz (350 watts at 30 MHz). PL519 (40KG6A) […]

FM Transmitter 3W by 2N3553

This is the schematic for an FM transmitter with 3 to 3.5 W output power that can be used between 90 and 110 MHz. Although the stability isn’t so bad, a PLL can be used on this circuit. This is a circuit that I’ve build a few years ago for a friend, who used it […]

SW RF Pre-Amplifier with 2N3819

A radio frequency amplifier to boost SW reception. Frequency range approximately 5 to 20 MHz. Parts List: R1 100k R2 1k R3 330 R4 47k R5 68k R6 4.7k VR1 4.7k C1 100n C2 220p C3 100n C4 1n C5 10n VC1 500pF L1 2.5m J1 2N3819 Q1 BC108B The problem with amplifying weak radio […]

VHF Band 2 Radio Spectrum tuning

VHF Band 2 Radio Spectrum tuning approximately With 2N3819 Circuit : Andy Collinson Email: This is a VHF amplifier for the Band 2 Radio Spectrum tuning approximately 88 – 108 Mhz. The circuit uses two 2N3819 FET’s in cascode configuration. The lower FET operates in common source mode, while the upper FET, operates in […]

TV Signal Amplifier by BFR90, BFR91, BFW92

This is a small, broad band, TV signal amplifier which covers the frequencies from 40 to 900 MHz. These frequencies include TV in VHF and UHF and also the radio broadcasting frequencies in the 88 – 108 MHz FM band. It is connected between the antenna and the input of your receiver and boosts the […]

FM Transmitter 4W by 2N3553

This is a small but quite powerful FM transmitter having three RF stages incorporating an audio preamplifier for better modulation. t has an output power of 4 Watts and works off 12-18 VDC which makes it easily portable. It is the ideal project for the beginner who wishes to get started in the fascinating world […]

40 Watt Amplifier For FM Broadcast by MRF171A

This amplifier was built based on Marconi’s website, A Design for a 40W broadband VHF RF Power Amplifier for FM broadcast. A few minor tweaks were made to the schematic and a few parts were changed to what I had available (mostly surface mount components). The heatsink is from an old Motorola Mostar 800 MHz […]


An improved crystal radio with a two-stage audio amplifier. The 2N3904 (or any other general-purpose NPN) acts as a preamplifier while the LM386 boosts the signal high enough to drive low impedance Walkman headphones or perhaps even a small speaker. Read More Source: Thank you.

VHF Audio Video Transmitter by BF494

The circuit presented here is a simple audio/video transmitter with a range of 3 to 5 metres. The A/V signal source for the circuit may be a VCR, a satellite receiver or a video game etc. A mixer which also operates as an oscillator at VHF (H) channel 5 TV frequency is amplitude modulated by […]

15dB UHF TV Antenna Booster by BF180

This is an UHF band TV antenna preamplifier circuit With 15dB gain to build easily. It is formed based on BF180 UHF Transistor. The first stage is an band pass filter constructed by the C1, CV1, L1, L4, C7 and C3, the second stage is a base-common voltage amplifier with low input impedance to match. […]

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