Archive for category: RF Radio circuits

1GHZ Frequency Meter

RF Radio circuits | By: Diagram mania

  1GHZ Frequency Meter   This is 1GHz frequency counter with 100KHz resolution. Meter is built in around PIC16F84A microcontroller and SAB6456 / U813BS prescaller.

15dB UHF TV Antenna Booster

RF Radio circuits | By: Diagram mania

  15dB UHF TV Antenna Booster   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 […]

1.5V Tracking Transmitter

RF Radio circuits | By: Diagram mania

  1.5V Tracking Transmitter   With this circuit you can build a very small tracking transmitter that can be tracked using a FM broadcast band radio receiver. The transmitter can be powered from any 1.5V volt battery or power supply. Transmitter has a range up to 1 mile depending on battery voltage, height above ground, […]

1.5V FM Broadcast Transmitter

RF Radio circuits | By: Diagram mania

  1.5V FM Broadcast Transmitter   The objective of this 1.5V FM Broadcast Transmitter design is to provide a simple low-power transmitter solution for broadcasting audio from various audio sources. This transmitter accepts stereo input via two 470K resistors. Since there is no audio level control on the input, the audio level out from the […]

1.5V Battery Operated Rebroadcast FM Transmitter

RF Radio circuits | By: Diagram mania

  1.5V Battery Operated Rebroadcast FM Transmitter   This implementation is adapted to rebroadcast the output of a CD player, television receiver, or radio receiver. I use it so that I can move about the house and listen to my favorite programs without disturbing others. Within and the house, I find that I can get […]

1 Watt QRP Power Transmitter

RF Radio circuits | By: Diagram mania

  1 Watt QRP Power Transmitter   The 1 watt 20 meter QRP transmitter with VXO. This is a nice QRP transmitter that can be used in combination of one of the simple receivers. Normally these designs have only two transistors: one is the X-tal oscillator and the second the final amplifier. A good example […]

1 Watt Four Stage FM Transmitter

RF Radio circuits | By: Diagram mania

  1 Watt Four Stage FM Transmitter   This FM transmitter circuit uses four radio frequency stages: a VHF oscillator built around transistor BF494 (T1), a preamplifier built around transistor BF200 (T2), a driver built around transistor 2N2219 (T3) and a power amplifier built around transistor 2N3866 (T4). A condenser microphone is connected at the […]

0.1 – 3.5GHz Prescaler

RF Radio circuits | By: Diagram mania

  0.1 – 3.5GHz Prescaler   This handy prescaler divides input frequency by 1000. It takes maximum input frequency of 3.5GHz and converts it into 3.5MHz that may be measured using standard frequency meter.

TX-500 500mW FM Transmitter

RF Radio circuits | By: Diagram mania

Click on the image to enlarge the schematic. Please be advised that it might be illegal to use this transmitter. This project is presented here only for educational purposes. About TX500 – 500mW FM Transmitter   The TX500 is a simple to build 500mW FM Transmitter. It consists of three blocks; modulator / oscillator, two […]

TX-300 300mW FM Transmitter

RF Radio circuits | By: Diagram mania

This power meter will let you test both the output power of Q2 (VHF amp) and Q1 (oscillator). Circuit is now on the separate board so you can fit the main circuit of the smaller PC board.   About TX300 – 50-300mW FM Transmitter   Here it is a brand new TX300 FM transmitter. The […]