Products > Test Equipment
Hantek6074BC-hack to 250MHz
BillyO:
--- Quote from: luanscps on January 25, 2023, 09:55:11 pm ---I have a 6074BE, I'm interested in this hack.
Has anyone managed to get it to work at 250mhz?
I am willing to do firmware tests on my device
thx
--- End quote ---
Yes. It does so right out of the box.
If you are using just one channel you have a 250MHz scope (actually I was able to sweep mine out to 270MHz @ -3dB) @ a maximum of 1Gsa/s. If you enable a 2nd channel it will drop to about 125MHz and then if you enable 3 or more you get only 70MHz. You also drop to a max of 500sa/s and then to 250sa/s as you add channels. My guess is that the ADC is different for the 6254.
gf:
--- Quote from: BillyO on November 19, 2022, 04:07:14 pm ---I guess no one has figured out the difference between these models? Still no way to "improve" the 70MHz version to 250MHz?
--- End quote ---
I measured a -3dB point of ~270MHz for my 6074BD. Not perfectly flat. Some peaking at ~150MHz. So I guess, the difference between 6074BD and 6254BD is just the label and the price. I'm also not aware of any software-adjustable lowpass in the frontend. ADC is a HMCAD1511. Don't know if "BE" is different in this regard.
coromonadalix:
on the pcie connector, you have the usb port pins i think ?
And you seem to have one or a very few pins who goes somewhere ??
rtek1000:
From what I understand about ADC, 10 samples are needed for each Hz, that is, if all 6xx4 use the same ADC HAD1511 of 1GSPS then you can only get 100MHz of bandwidth.
Anything above that is just marketing.
See here: https://www.analogictips.com/adcs-sufficient-sampling-nyquists-rate/
Someone can create a custom firmware for the FPGA and thus be able to use all that 1GSPS, but it may be easier to buy the 100MHz bandwidth model.
Changing from 70MHz to 100MHz would only be a 30% improvement.
Some oscilloscope models have 5 ADC of 100MSPS to get 1GSPS, it may be possible to put more HAD1511 in parallel to get a higher sample rate (There yes is a respectable hack).
See here:
https://sigrok.org/wiki/Rigol_DS1052E
BillyO:
--- Quote from: rtek1000 on April 28, 2023, 11:19:31 pm ---From what I understand about ADC, 10 samples are needed for each Hz, that is, if all 6xx4 use the same ADC HAD1511 of 1GSPS then you can only get 100MHz of bandwidth.
Anything above that is just marketing.
--- End quote ---
No, this is not correct. I have tested mine to 270MHz @ -3dB. Others have gotten the same result. So, lets call it 250MHz. That's 4 samples per cycle or .25cycles per sample, which is plenty and typical for DSOs. The real facts are out there and you could look them up ... :-//
From Wikipedia:
--- Quote ---In signal processing, the Nyquist frequency (or folding frequency), named after Harry Nyquist, is a characteristic of a sampler, which converts a continuous function or signal into a discrete sequence. For a given sampling rate (samples per second), the Nyquist frequency (cycles per second) is the frequency whose cycle-length (or period) is twice the interval between samples, thus 0.5 cycle/sample.
--- End quote ---
From Keysight:
--- Quote ---If you don’t want the oscilloscope to select the sample rate for you, most oscilloscopes allow you to set the sample rate yourself. If you set the sample rate yourself, remember: two times the frequency is the absolute minimum rate you should use. When it comes to oscilloscopes, I recommend choosing a sample rate faster than this. Usually choosing a sample rate that is 3 to 5 times the bandwidth of the oscilloscope will give you a high-enough sampling rate to capture the details of your signal, including its frequency of oscillation and the rise times of your waveforms. You need a sample rate that will provide enough detail to see any unexpected glitches or anomalies.
--- End quote ---
From Tektronix:
--- Quote ---In order to accurately reconstruct a signal and avoid aliasing, the Nyquist theorem states that the signal must be sampled at least twice as fast as its highest frequency component. This theorem, however, assumes an infinite record length and a continuous signal. Since no oscilloscope offers infinite record length and, by definition, glitches are not continuous, sampling at only twice the rate of highest frequency component is usually insufficient.
In reality, accurate reconstruction of a signal depends on both the sample rate and the interpolation method used to fill in the spaces between the samples. Some oscilloscopes let you select either sin (x)/x interpolation for measuring sinusoidal signals, or linear interpolation for square waves, pulses and other signal types.
For accurate reconstruction using sin (x)/x interpolation, your oscilloscope should have a sample rate at least 2.5 times the highest frequency component of your signal. Using linear interpolation, the sample rate should be at least 10 times the highest frequency signal component.
--- End quote ---
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