Questions tagged [attenuator]

An attenuator is an electronic device that reduces the power of a signal without appreciably distorting its waveform.

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98 views

Attenuator Input Voltage Problem

simulate this circuit – Schematic created using CircuitLab I'm trying to use an attenuator with a PIC32 microcontroller. Basic idea is that; 1) I enter attenuation value through computer 2) ...
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3answers
71 views

Power Ratings of RF Attenuators In Series

If I connect RF attenuators in series, does the power rating of the attenuator closest to the antenna have to be high enough to handle the expected RF power on its own? Or does the placing attenuators ...
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1answer
275 views

61000-4-6 CDN calibration - how to factor in the 6 dB attenuator?

I am seeking some clarification around CDN calibration for 61000-4-6 (RF conducted immunity test). By following the standard and some application notes, I am pretty sure I have it sorted. I just ...
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1answer
48 views

Lpad wiring, is gnd needed?

I'm building an attenuator using an Lpad. Do I need to connect '1' to GND? What difference will it make? Here's my circuit (Fritzing didn't have mono-jack connectors or an Lpad, so I'm using the ones ...
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How can I attenuate a video signal in discrete steps using digital control? [closed]

I would like to use a μController to adjust the brightness of VGA/EGA RGB signal. My intention is to allow for a setting from "full brightness" (0% attenuation) to "completely dark/black" (whatever ...
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Why do 0 dB attenuators exist?

I am reading this paper : Upgrade of a low-temperature scanning tunneling microscope for electron-spin resonance and found that for thermalization, they use 0 dB attenuators. Page 6: Having the ...
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1answer
86 views

Active analog attenuation with OPA2340

I wish to have active analog attenuation circuit. Following this page, I got myself some OPA2340. I use the B-side to keep the numbering somewhat intact. I go with the design on Figure 16-2 (p. 14/...
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2answers
113 views

RF Attenuator Failure

I am attenuating an audio frequency (50 KHz) signal that is pulsed at 666 W for 300us with a period of 300ms. I estimated the power dissipated averaged over a period to be approximately: \$\frac{300 \...
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1answer
95 views

DB25 to TTL logic (voltage control) [closed]

I am trying to control a 6-bit digital step attenuator for a project, with an Arduino (here, Arduino Due or Arduino Mega). The given attenuator has a software to control it. So, I connected the ...
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2answers
591 views

Adding audio-in port to plasma ball with built-in Microphone

I have a Plasma Ball with a built in microphone and would like to add another switch S1 and an audio-in port to the circuit J1. How do I calculate the line attenuation R1 and R2 resistors? My idea ...
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1answer
73 views

Energies of the fields in a plane wave, attenuated and unattenuated

This is a combination of two of my previous questions (question 1 and question 2) which are related. I'm trying to learn both how energy is carried in the electric and magnetic components of a plane ...
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1answer
76 views

What are the mechanism and effects of non-linearity in an attenuating barrier in the presence of a high-strength EM field?

It's my understanding that in electromagnetics, if an attenuating device is functioning linearly, it means that 1) input and output signal strengths are proportional; and 2) input f = output f. How ...
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1answer
155 views

Linear and non-linear attenuator

[edit 3/2/18] There are problems with the title and wording of this question. I would edit, but to do so would alter the relationship between the question and the answer that I accepted. So, I have re-...
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59 views

Strong H fields: electronic items susceptible to thier damaging effects and how to shield them

This is another question related to magnetic fields. I'm trying to determine the thickness of copper foil that would be required to shield common electronic items from H fields of about 133 A/m over ...
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3answers
69 views

The electric and magnetic components of far field EMR and shielding thereof

This is a newbie question. I'm pretty sure of the answer, but I would like confirmation. I found this thread in this forum that came close to what I was looking for, but I think my question is ...
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823 views

SNR and Attenuation Question

Hello, I have a question above from random material and tried to solve it. Here, I assume signal power to be S1(dB) and noise power to be N1(dB) at input, and S2(dB) and N2(dB) at output. So below ...
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What does the attenuation setting do in an RF spectrum analyzer?

I have to make measurements of the RF power which a circuit is delivering, and I am using an RF spectrum analyzer for that purpose. I am a beginner in this topic, so I apologize if the question is too ...
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3answers
115 views

Characterization of RF Amplifier Chain

I am using a 3 Amplifiers chain for a Receiver system. The required Output is -32dBm while the sensitivity of the system is -55 dBm, I am able to achieve this. But the maximum I/P power for the ...
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2answers
673 views

problem solving: line level to iphone attenuator buzzing sound

I'm trying to use the mic input on my iPhone to record line level audio. I have made a cable with an attenuator as shown in the picture below. Recording from my macbook pro works like a charm (3,5mm ...
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3answers
386 views

Transformer provides no attenuation for differential transients

I have read few articles about transformers and they all point to the fact that they are excellent attenuators for common mode transients, but not for differential mode transients! One of this ...
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1answer
281 views

Audio attenuator has audible pops

I'm copying the recommended circuit (the 'Higher Performance' one, actually) from the LM1971 audio attenuator datasheet but there are audible (loud) pops on the output. I'm using OPA227s for all op-...
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1answer
351 views

Adapting an HF attenuator to higher power

I want to make a 25W HF amplifier that can handle an input up to 8W. I found a schematic by ON6MU which can handle up to 2.5W input. There is an attenuator at the input that I copy here. R3-4 is 1W, ...
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Smith Chart Explanation

I'm working on designing some hopefully simple RF (912 MHz) attenuators. I need a few different levels of attenuation but each different attenuator can be fixed. I have prototyped one using just off ...
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2answers
685 views

Soft fade out circuit for turning off speakers

I have some loud speakers connected to an amplifier. The problem is when I turn the preamp off, it sends a loud POP noise through the speakers. The turn off of the amp is delayed by 1 or 2 seconds, ...
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226 views

Why are the ADC and DMM readings different?

While doing an experiment we reached a conclusion which we wrote down as the DMM and the ADC reading being different. Now after doing some research It does confuse me as a DMM does contain an ADC of ...
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456 views

Bandpass Filter Attenuation?

I'm trying to split an audio signal into 5 channels, letting 5 different ranges through each filter (low, mids, highs, etc..). What I'm finding is that each bandpass filter has different levels of ...
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2answers
555 views

Compensated Attenuator question

In the explanation, it explains that C2, C3, C4 are for frequency compensating the impedance of C1 which varies according to frequency. Can someone explain how C2~C4 does it? and why the designer ...
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2answers
793 views

How to test an RF attenuator with limited tools

I have an RF attenuator with the specification: Freq DC to 3 GHz 30dB attenuation 2W avg power rated VSWR = 1.2 max Imp = \$50\Omega\$ How can I test this attenuator without a spectrum analyzer? I ...
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1answer
75 views

generating a 10mVpp signal from computer

I have an input to a system that requires a 10mVpp max signal. I have to use my computer to input it due to constraints out of my control. I am well aware an audio card cannot go down that low. I ...
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2answers
483 views

Audio Mixer Passive Attenuator Circuit

I'm currently designing a digital audio mixer. One common thing found on audio mixers is a optional 20dB pad on the input. I've seen some attenuator circuits but all of them require you to know your ...
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1answer
734 views

Why does inserting a resistance in the common of my scope probe cause it to pick up AC noise so much worse?

I'm poking at the inside of a USB oscilloscope, with the hope of modifying it so that the scope probe commons can be referenced to different voltages. When I use my USB oscilloscope to measure a 24V ...
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2answers
860 views

Analog vs Digital attenuation for an ADC

I'm designing a digital parametric EQ that will go in front of a high gain guitar amplifier. I want to have the option to boost signals up to 12dB. I plan on implementing this either by attenuating ...
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2k views

Is there a difference between voltage divider and attenuator?

I am thinking about using a voltage divider to scale down the signal by 2/3 (-1.76 dB) as the following circuit diagram: simulate this circuit – Schematic created using CircuitLab When I ...
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1answer
138 views

In what order should I isolate and attenuate an audio signal?

I have a cheap bluetooth audio module (with no documentation) that outputs a signal greater than line-level. It was probably designed to be connected directly to small speakers, since the ground on ...
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2answers
4k views

Best topology for active attenuator

What are the advantages and drawbacks of each op-amp attenuator topology ? Which one would you use ? Resistor divider followed by a buffer : Inverting op amp attenuator :
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Is there a 10X probe compensator BNC, but with out the probe?

Is there such thing as a compensation BNC like the ones found on 10X probes? I'm basically taking about a BNC coupler with a resistor and a adjustable cap in it. I guess it would be like a standard ...
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2answers
654 views

OpAmp: Better to actively attenuate, or drive full range into a divider?

I want to get a +-15V differential signal (60Vp-p) into an ADC that has a single 3.3V supply. When I asked a friend to proofread it, he was concerned about the noise performance of R5-R6 vs. using R1-...
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2answers
552 views

Using Op-Amp for attenuation to give input to sound card

I know there is lot of question asked about this topic before, I read them but there are some limitation on those circuits which make me ask this one. I want to do analysis of main voltages(220/50Hz)...
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1answer
882 views

RF load (terminator) at the end of RF attenuator

Do I need to install RF terminator at the end of RF attenuator? Let's say that max power output for RM port is 50W and I'm using 100W 50dB attenuator. What if I was using 50W 40dB attenuator? Is there ...
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3answers
780 views

Unbalanced pi- attenuator - Problem with simulation

I've been trying to simulate the asymmetric pi-attenuator example on this page with different source and load impedances: http://www.electronics-tutorials.ws/attenuators/pi-pad-attenuator.html I ...
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2answers
174 views

Digitally controlled smoothly variable gain?

I have a circuit that outputs about 600mVpk wave shape. I need to be able to output between 10mVpk to 10Vpk accurately, preferably with no calibration but a known error. The whole process should be ...
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1answer
141 views

Can someone please explain this attenuation setup?

This is a part of an Agilent signal generator output attenuator. These are 4 or 5 of these stages with the resistor setup as shown, different values at each stage to set different attenuation levels ...
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1answer
443 views

Passive Voltage Divider attenuator design technique

I want to build a passive attenuator which will attenuate an input signal. I want the to have 12 steps, starting with no attenuation and with each subsequent step having a 0.5dB attenuation (so down ...
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1answer
764 views

Is it possible to design this circuit with a single potentiometer (L-pad)?

I'm designing an L-Pad for my speakers. They attenuate the signal while keeping a consistent effective impedance, which is necessary for the amplifier and crossover circuits. Typically, these values ...
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3answers
3k views

How can I make a simple voltage-controlled attenuator?

Having discovered just how awful the AC ripple is on some of my 5VDC wall-adaptors, I decided to make an Arduino program to calculate the RMS AC component and DC component of an adaptor under varying ...
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2answers
139 views

are amplifier and attentuator bascially of the similiar function?

I just got a very old function generator (I can't even tell the manufacture and the model number) to produce sine wave. I open it and see a big module label video amplifier. The function generator ...
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how to derive resistance vaules (attenuator)?

Let's say we have this types of attenuator pads: How do we derive their resistance values? like shown below Where did Zo, k come from? How about R5, R3 and R7? edit: Zo represents the ...
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1answer
345 views

Measured VS Ltspice Difference in P-Chan JFET Attenuator

The following circuit is a slow switching +-15V audio signal attenuator: Why are the measured voltages (shown in white boxes) so different from the SPICE values (shown in the graph)? Note that ...
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2answers
762 views

Voltage Controlled Attenuator

I'm trying to create a DC voltage attenuator which linearly scales the loss relative to an applied control voltage "Vc". In other words, K = Vout/Vin is a linear function of Vc. Vin is guaranteed to ...
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2answers
1k views

Attenuator for guitar amp cheap DIY

I have a Peavey LTD 400 steel guitar amp. I want to overdrive the tubes in it, but it is a very loud amp. To practice I would like an attenuator between the amp and the speaker. I've seen a lot of DIY ...