# Questions tagged [frequency-measurement]

Anything related to the measurement of the frequency of periodic signals, i.e. the rate at which their waveform repeats along the time axis. The S.I. unit for frequency is **hertz [Hz]**.

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### Understanding dBm value of FFT measurements

I am getting familiar with the FFT functionality of my oscilloscope. I am using a Siglent SDS2204X Plus that has been firmware upgraded to 350 MHz. Testing of the FFT function involves the use of a ...
• 127
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### What does the standard deviation of TIE measurement tell me about my clock signal jitter?

When we take a Time Interval Error (TIE) measurement of a clock signal, we are presented with two measurement outputs, the mean error and the standard deviation. When I measured the TIE of a 32....
• 229
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### How can I convert a sine wave generated by PWM technique into a square wave?

I have generated a variable frequency sine wave by PWM using an Arduino Uno. I want the obtain a square wave using the generated sine wave, so I used an op-amp to remove the DC offset in the sine wave ...
79 views

### Frequency meter (counter)

I am currently working on designing a circuit that should be able to measure the frequency of an input signal by giving off a value directly proportional to the frequency at the input. The circuit ...
• 129
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### How safe is this TrueRife F-122 frequency generator?

A close friend bought a TrueRife frequency generator in hope of improving health.  I'm skeptical of the claimed healing powers, however let's put this aside for a moment;  if it helps - great!  The ...
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151 views

### Measuring magnetic fields in the 1-10 Hz range

I apologize in advance but I am a chemist just venturing into the world of electrical, so you may need to explain to me like a 5 year old. I have a chemistry project that involves the use of AC ...
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1 vote
215 views

### Easiest way to get highly-accurate frequency reference?

I just want to check the calibration of my frequency counter, so anything constant under 250 MHz would work(?) Mains are synced to atomic clocks, to maintain wall clock accuracy, but only ...
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104 views

### Understanding inductance and its dependency with frequency

I am trying to understand how to design an inductor that has constant parameters over a wide range of frequencies. Especially over high frequencies because I want to use them for impulse testing ...
• 324
1 vote
106 views

### Why does the length of an RG-316 coaxial cable affect the crystal resonator frequency response?

I was measuring a 32 [kHz] crystal resonator using a ZURICH HF2LI with 50 ohm input and found that the length of the coaxial cable will affect the frequency response or have a little difference at ...
• 141
1 vote
54 views

### Low power low speed pulse divider?

I have a digital input which receives irregular pulses. I want a circuit that takes that input and generates an output pulse for every 100 (or so) input pulse. The expected input speed is 10-300 Hz. I ...
256 views

### How to measure the frequency of a low frequency signal?

I am looking to measure the rpm of a wind turbine, the wind turbine is 3-phase synchronous generator, the frequency range I am looking to detect is between 1Hz to 60Hz, I tried to use a frequency ...
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### Why is there a high minimum current required for a clamp meter to measure frequency in addition to current?

Modern clamp meters use hall effect sensors to measure AC and DC current and normally calculate True-RMS. But for the meter to display the frequency of the measured current some require significant ...
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### Simple detection of a transient FM frequency shift

I have an application with a 2D array of inductive sensors for position detection of an object on a plane. I have experimented with inductance to digital converters (https://www.ti.com/product/LDC1314)...
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133 views

### How to make fast capacitive touch buttons without a microcontroller

(I have already read this question.) I am looking to make a musical instrument with a series of capacitive buttons in a grid of 17x4 buttons, with a length of about two feet and a width of three ...
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### How do I identify the value of a crystal oscillator?

How do I discover the frequency of a two-pin (to be used with two through holes) silver crystal oscillator which is inscribed with only: ...
367 views

### 3dB Cutoff Measurement vs (Calculated + Simulated)

I am stumbling upon a very strange situation unless I did something totally wrong in my measurement setup. Speaking of it, I've installed an acoustic measurement tool (REW) and measured for testing ...
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### Decode chirping frequency with uC at center frequency of around 100kHz

Context For my MSc project I'm building a chirping signal (a bit like LoRa) with a center frequency of 100 kHz. For now, the bandwidth is 10 kHz such that I have around 10 periods per chip. For ease, ...
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### How to get freq stability with constant offset for PLL synthesizer?

I used ADF5356 PLL synthesizer. And i use reference oscillator freq is 10MHz with initially offset 0.1ppm and stability is 10 ppb. I need to output freq is 3750 MHz. Expected output result: 10MHz × 0....
110 views

### How can I use a 555 timer and a binary counter to determine the frequency of a square wave pulse?

I'm trying to build a circuit to determine the frequency of a given square wave pulse. The pulse will be generated by a function generator. I have a 555 timer, a binary counter, a seven-segment ...
• 13
102 views

### Circuit Analysis for Frequency-to-Voltage converter

I'm struggling to understand how this FV converter by bob pease works. It's published here https://www.electronicdesign.com/technologies/digital-ics/article/21800808/whats-all-this-frequencytovoltage-...
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### Appliances from Saudi Arabia in Europe? [closed]

I got my hands on a Xbox Series S on my trip to Saudi Arabia and now that I am going back home I came to a sudden realization that electricity is in a different configuration to the one in my home ...
161 views

### Getting this common crystal tester to measure very high frequency crystals, resonators & oscillators

So these common crystal tester types have 50MHz as their frequency counting ceiling. How do I make them be able to measure the fastest crystals, resonators & oscillators (the latter two going up ...
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154 views

### Frequency measurement with counters

I'm trying to get the following circuit to work. It says to: Connect the circuit as shown in the block diagram in Figure 2 by adding a NAND gate followed by a CD4029 connected as a decade counter. ...
• 57
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### Fractional N Synthesis and Frequency Meters

I Updated the question twice at the bottom I bought a 30-year-old frequency meter from EBay. It has the ultra-stable OCXO reference option, but hasn't been calibrated in 9 years. It seemed to work ...
• 1,042
248 views

### Frequency Counter Input Impedance

I have been looking at RF frequency counters and noticed that they all have one port that says up to 50 MHz with an input impedance of 1 megaohm. However the +50 MHz input says 50 Ohm impedance. If ...
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1 vote
108 views

### How to measure radio wave penetration and reflection through different mediums

I would like to do a few experiments to test how different EM radiation frequencies (915 MHz to 5 GHz) interact with 3D print filament materials (like PLA, PolyCarbonate, TPU, etc...). Specifically I ...
1k views

### IC for measuring frequency [closed]

In my application, I need to measure frequency in the 1 to 500 MHz range. Since this frequency is a bit too high for microcontrollers, I am wondering if anyone knows an approach to solve this problem, ...
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### What is the shortest pulse a controller can count?

I want to count short LVTTL pulses (about 20-25 nanosecond.) Right now, I use an Arduino with four IN74AC161N binary counters, but this solution has some Arduino limitations. I count pulses, send the ...
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### MAX9926 Maximum Variable Reluctance Input Frequency

I am planning on using the MAX9926 to read 2 variable reluctance (magnetic pickup) sensors installed in the crankcase of an engine. The sensors will read the teeth of the starting gear to get the RPM ...
369 views

### Gain at zero hertz

I have attached the figure of my circuit. I know that as the frequency rises the gain of the circuit decreases due to low pass filtering but what if I want to measure the DC output voltage ( 0 Hz) ? ...
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### Frequency converter for spectrum analysis

I have an oscilloscope/spectrum analyzer that has a maximum sampling frequency of 20MHz and I would like to analyze the spectrum of a higher frequency band (also 20MHz wide) for example 90-110MHZ to ...
332 views

### Linear and log sweep in AVR

My application requires a frequency sweep in a coil and measuring the resultant resonant frequency from the coil after it has settled. I can do the second part i.e. wait and count the rising edges of ...
1 vote
571 views

### Measuring relative phase of two clocks

I'm working on an FPGA and I have implemented a component that can take a clock and dynamically change the phase. Now I think there are some problems with this component because the target of the ...
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### Two resonances in the admittance of capacitor C

I have this question that has been haunting me for a week now. I was given a measurement file of a previous student. Allegedly, they are the measurements of the admittance of a circuit that is ...
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### Capturing mains AC waveform with audio recording device

I'm wondering how practical (read: safe) it would be to use an audio capture device to "record" a mains AC signal for the purposes of monitoring the characteristics of the AC sine wave. I am ...
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235 views

### Degenerated signal at a logic level converter

I'm trying to pair a motor controller, and a bi-directional logic level converter to feed a microcontroller with a motor speed signal. Some signals have already been successfully converted, but a ...
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534 views

### What sampling rate is needed for demodulating and decoding GPS signal data?

I just got a software-defined radio (SDR) and am trying to record GPS frequency (L1 1575.42 MHz). I understand that GPS is modulated using Binary Phase Shift Keying. I also read about the Nyquist ...
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### Electret microphone amplifier to control an LED strip

First sorry about my English. So my problem is so simple but I can't figure it out. I have a frequency to voltage circuit which is working perfectly but I want to control it by the voice. https://...
73 views

### Negative frequency deviation in crystal oscillator

What is the significance of a negative frequency deviation in the freq deviation vs temperature profile of a typical OXCO (e.g. the diagram seen on this page)? My understanding is that a positive ...
1 vote
2k views

### How to use the rate of change of frequency equation to calculate frequency drop in a grid based on lost generation

My question involves calculating the frequency drop in a power grid when a load is lost. The closest question I have found to mine is, Change in frequency in a grid that has lost generation? Based on ...
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### The effects of frequency resolution in FFT on the frequency spectrum

This is a section for the parameter study of my thesis (basically: why and how I did what I did in the experiments). Currently, I have to choose the fit bandwidth and FFT lines combination for the ...
60 views

### how to apply frequency-dependent attenuation to a signal

Let's suppose a signal like this: the frequency domain plot of such a signal is: Now, What I intend to do is to apply a frequency-dependent correction to the signal. For example, the attenuation ...
434 views

### Measuring frequency of a coin vibration motor

I'm trying to determine the change in frequency with voltage of a coin vibration motor (https://solarbotics.com/product/vpm2/) using an oscilloscope. So far I have tried two different set ups. Set up ...
157 views

### Obtaining frequency of 550 Hz from Simple Triangle and Square Waveform Generator Circuit

First time asking a question so sorry if I miss some things. I'll try to be thorough and straightforward. I'm trying to design a square wave from a triangle wave-square wave generator circuit. The ...
1 vote
152 views

### 1200W, voltage and cycle converter 220 to110

I have bought a Joule sous vide immersion circulator from USA. I want to use the device in India. I need to convert AC, 240V 50Hz to 110V 60Hz. After reading the literature on the company's website ...
3k views

### Simple high frequency (GHz) RF radiation detector

I want to build a simple RF radiation detector that shows if there are any RF devices transmitting at a certain frequency. I want to use it to detect RF radiation in the 2.4 and 5 GHz range. I have a ...
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1 vote
345 views

### How to measure microwave frequency with Lecher lines

I am working on a project where I need to measure the frequency of some microwaves (up to 10GHz) and as measurement tool I chose Lecher lines as they are easy and fast to build. However after building ...
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### How to identify the type of modulation and data rate of an RKE system transmission

Many devices that measure frequencies of key fobs, can inform, in addition to the frequency measurement, also the type of modulation, FSK or OOK, and the data rate in bps. Previously in this forum, I ...
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### Which frequency measurement method is more suitable for RF signals from 200MHz to 915MHz?

I need to build embedded circuit, an RF frequency meter (also known as RF frequency counter) to measure frequencies of remote key fobs. The frequency range I need to measure is 200MHz to approximately ...
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1 vote