Fluke/Philips PM66xx frequency counter OCXO upgrade

Dan Watson documented on his blog an OCXO upgrade board he designed for the Fluke/Philips PM66xx line of frequency counters: My counter came with the standard XO timebase option, which has fairly poor specs for stability and drift. It is difficult to trim precisely with the single-turn trimmer capacitor on the board. For most testing […]

Nanocounter is an accurate frequency counter using an FPGA, STM32 and a bluetooth android app

Andy Brown has designed and built a frequency counter using an FPGA, STM32F072 and an Android GUI – the Nanocounter: After studying the above counting methods I decided on the following goals for my frequency counter, which I’m going to call Nanocounter. Very accurate measurement over a range of 1 to 50MHz. This would cover the range […]

Audio oscillator with frequency counter

Xristost blogged about his DIY Audio oscillator with frequency counter project: After I finished the oscillator, I made some minor changes in the square signal part of the schematic. I connected five of the inverters in parallel with low value load resistors, thus reducing the influence of the parasitic capacitance of the PCB. The goal is […]

Frequency counter with PIC16F628A

xristost blogged about the frequency counter module he made: First of all I wanted a PIC microcontroller to do the whole job without any additional ICs. Also I wanted to use the the familiar 16F628A, but because one of the portA pins (RA5) can be used only as input I was short of outputs to do the […]

Talking Electronics Frequency Counter

John Boxall over at Tronixstuff has a detailed review of Talking Electronics’ Frequency Counter: The counter works by using a multi-vibrator using a CD4047 to generate a square-wave at 50, 500 and 5 kHz, and the three trimpots are adjusted to calibrate the output. The incoming pulses to measure are fed to the 4026 decade counter/divider ICs. Three of […]

Reciprocal frequency counter

Alan built a reciprocal frequency counter. What sets reciprocal counters apart is that they adjust to the signal measured, sort of an auto-ranging feature. It is AVR based and automatically enables or disables a prescaler to handle frequencies from 0.5 Hz to 100 MHz. It can give the same precision whether the signal is fast […]

XC9572XL breakout board: Frequency counter

Jason implemented a frequency counter on an XC9572XL CPLD. It uses a 1Mhz clock to count the duration of the input signal pulse, and shows the output on a 6 digit display. Initially he had to use additional 7400 logic ICs to convert BCD output from the CPLD to the 7-segment displays. With some tweaking […]