Wiring Schematic Diagram

This project explain a very powerful frequency counter which has many useful software functions.
The software can add or subtract 3 different IF frequencies (±455 kHz ,±10.7 MHz and ±21.4 MHz).
You have also two level of resolutions, 1kHz and 100Hz.
The main oscillator can be on-board 13MHz or external 10 MHz.
The counter data can easy be transmitted to computer with RS232 cable (software below)
The construction is extremely simple and the unit is very small.
This project comes in a KIT version, se more details below.

Background
Once again, It is time to update the frequency counter.
A frequency counter is one of the most important measuring tool we need as homebrew's of RF electronic.
This frequency counter has very high performance and still is very easy to build and to use.
Anyone can build it and have a professional frequency measuring tool.
The counter is based around a LCD display with 2 lines and 16 chars.
I have used a HD44780 based display which is very common.
A PIC16F870 circuit controls all counting and display functions.
A prescaler is added to make it possible to measure up to 2.5GHz with high sensitivity.

The Display Module Size (W x H x T): 80mm X 36mm.
The controller PCB has the same size. This makes the unit very small and slim.

In the menu system of this frequency counter, you can choose between two reference frequencies.

· On-board 13.000MHz crystal (picture at right), or

· External 10.000MHz signal.
The reason of using a external 10.000 MHz reference frequency is because it is common among reference oscillators, as HP Z3801 GPS locked frequency source.