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Simple XR2206 function generator for self-assembly - Made in China - Review

CMS 9585 18

TL;DR

  • A simple self-assembly XR2206 function generator kit from AliExpress was assembled and tested in a laser-cut enclosure.
  • It provides sine, triangle and square outputs, five jumper-selected ranges from 1Hz to 1MHz, and runs from a 9VDC-12VDC barrel jack.
  • The kit cost about PLN 17, while similar generators in Poland were said to cost up to PLN 90 plus shipping.
  • Waveform quality varied with frequency, and the amplitude knob worked in reverse, with maximum output at the leftmost setting.
  • The included screws were too short for the populated PCB, so longer M3 screws and spacers were needed, and the generator really needs an oscilloscope because it has no display.
Generated by the language model.
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Treść została przetłumaczona polish » english Zobacz oryginalną wersję tematu
📢 Listen (AI):
  • Hello my dear readers. I was gone for a while, because there was a lot of work and some holidays on the way, and some spring sickness spread me.
    Anyway, I'm here again :) .

    Today I will review a very simple function generator from our slant-eyed friends. The generator is based on the popular XR2206 chip.
    Simple XR2206 function generator for self-assembly - Made in China - Review
    For the amount of about seventeen Polish zlotys, we can buy mini generators on Aliexpress, offering us sinusoidal, triangular and rectangular waveforms in the range from 1Hz to 1MHz. With friends you have to pay for it around PLN 17, in Poland up to PLN 90 plus shipping.

    Let's start with the presentation of the contents of the shipment.
    Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review

    As you can see in the pictures, we get a kit for our own assembly, i.e. the so-called KIT.
    As usual in such cases, we start with soldering the "lowest" elements.
    Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review
    What wnikliwsi of you will notice that one condenser is several dozen years older than the rest. Well, the Chinese made a mistake and gave 104 instead of 220, so I had to pick some "from the drawer".
    Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review
    After assembling the tile, it looks like this.

    Time for housing. The manufacturer was so kind that when laser cutting the forms, he also decided to engrave descriptions on the front of the panel. It is definitely a plus.
    Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review
    Unfortunately, when assembling the housing, it turned out that the Chinese did not think everything properly. The screws that are included in the kit and are to screw the PCB to the housing, would be perfect in length if we wanted to screw the "bare" PCB. Unfortunately, after soldering the elements, the thickness of the board increases by the thickness of the solder and the cut ends of the leads and it will not be possible to put it together. So you have to keep in mind that we have to get longer M3 screws and some distances between the plate and the bottom part of the housing. I used rubber pads made of a piece of tubing.

    Now it's time to mention the technical side of this device.

    1. The device is powered by a DC Jack connector. The plug dimensions are 5.5mm x 2.5mm. Standard plus in the center, minus on the housing.
    2. The system tolerates the supply voltage in the range of 9VDC - 12VDC.
    3. The generator has the following waveforms:
    - Sinusoidal (jumper selectable) on the "lower" pin of the ARK connector.
    - Triangular (as above, selected with a jumper) on the "lower" pin of the ARK connector.
    - Rectangular (permanently given, regardless of the jumper settings), on the middle pin of the ARK connector.
    4. We have five compartments (set with a jumper):
    - 1 - 10Hz.
    - 10 - 100Hz.
    - 100Hz - 3kHz.
    - 3kHz - 65kHz.
    - 65kH - 1MHz.
    For all waveform types (at least theoretically).
    5. We also have three potentiometers:
    - AMP - regulates the signal amplitude in the following ranges:
    - for a sine wave: 0-3V / with a supply voltage of 9VDC
    - for a triangle wave: 0-3V / at 9VDC supply voltage
    - for square wave: 8V - no adjustment possible / with 9VDC supply voltage.
    Unfortunately, the regulation works "in the opposite direction". So turned all the way to the right, it is the smallest signal level. Believe me, it can really make life difficult. Already when taking photos for the article, it took its toll.
    - Fine - for fine tuning the frequency of the waveform.
    - Coarse - for coarse adjustment of waveform frequency.
    Fortunately, the latter two regulate in the normal direction.
    6. There is also the mentioned three-pin ARK connector with GND, Square and Sinus / Triangle.

    I noticed that the ranges set with the jumper do not exactly match the reality. For example, the maximum frequency in the range up to 10Hz is 20Hz, and in the range up to 100Hz it is 200Hz.
    However, I noticed that if in a given range, we exceed the frequency set with the jumper, the waveform can change drastically. Although it does not have to be, it depends on the frequency. The photos will probably tell the most.

    And finally, what you like the most, i.e. some pictures from the course of the tests.
    I decided to show the waveforms for each type and frequency on the basis of:
    - first range - minimum twist of the potentiometers, and then the maximum opening of the potentiometers. I am talking about the Fine and Coarse potentiometers, because I turned the Amplitude one only slightly when needed. The same for the other ranges, except the last one, because the oscilloscope did not work anymore.

    Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review

    Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review

    Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review

    Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review

    Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review

    Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review
    Sorry for confusing the order of photos but it's not my fault but electrode server error. However, I don't think it will be a big problem for you. After all, everything is clearly visible, only a little out of sequence.

    The above photos show the behavior of the course, from fractions of Hertz to two hundred kilos of Hertz. However, the pocket oscilloscope that I used for the review has the feature that above the mentioned frequency it starts to get lost.

    In the pictures we can also observe that the "quality" of the waveform is strongly dependent on its frequency. And this is just SINUS. In a moment I will present you a triangle and a rectangle where it is much worse.

    Another portion of photos.
    This time TRÓJKĄT, here the waveforms don't look so nice:
    Simple XR2206 function generator for self-assembly - Made in China - ReviewSimple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review
    Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review
    Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review
    Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review

    Well, we are going with a RECTANGLE:

    Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review
    Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review
    Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review
    Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review
    Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review
    Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review

    Here again, despite the confused order of the photos, it is clear that this generator is definitely the "worst-off" with the rectangle.

    As you can see, this is not a PERFECT generator, but what to require for the price.
    I would like to add that I also checked these "ugly waveforms" on the "old" "lawful" oscilloscope and they were just as nasty.
    I tried to take pictures, but the phone camera somehow didn't want to cope with the CRT oscilloscope screen and in the pictures I was only able to capture a "noisy" fragment of the waveform. For this reason, I have not included pictures of oscillograms from the CRT oscilloscope. However, I would like to add that the rectangle at low frequency did not resemble a rectangle either. It looked almost identical to it here
    Simple XR2206 function generator for self-assembly - Made in China - Review



    Summarizing.
    I am sure that such a cheap generator, additionally equipped with a fairly durable casing, can significantly facilitate the work of beginner electronics.
    The only requirement for this generator to be useful is to have any type of oscilloscope. Otherwise, the generator will be useless, because it does not have any display showing the given parameters.
    I recommend it especially for electronics from the AUDIO industry.
    The main disadvantage of this device is its "smallness" and lightness. It is the power cord that decides where the generator will lie :) . Some sucker feet would be nice.

    EDIT April 15, 2018:

    I'm sorry it's so late, but something came up and I wasn't going to come here.
    I am adding the promised photos of the waveforms in DC mode. The principle of measurement is the same as before.
    Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review

    Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review

    Simple XR2206 function generator for self-assembly - Made in China - Review
    Gulson introduced the amendment and I have the impression that the photos are no longer in a random order, but are added from the end.

    As for the oscillograms from a real oscilloscope, I really tried, took about forty photos for different waveforms and only managed to select a few photos where you can see anything.
    I only put them in "so that I don't want to try" :) .
    Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review

    Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review Simple XR2206 function generator for self-assembly - Made in China - Review
    It was impossible to capture the picture tube and oscilloscope settings at the same time.

    Best regards.
    CMS

    Cool? Ranking DIY
    About Author
    CMS
    VIP Meritorious for electroda.pl
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    CMS wrote 8440 posts with rating 2581, helped 256 times. Live in city Warszawa. Been with us since 2004 year.
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  • #2 17160491
    yogi009
    Level 43  
    Posts: 14662
    Help: 848
    Rate: 2646
    It's nice to see the construction based on old analog bones. I use my own design of an audio generator based on the ICL8038 (ceramic original from Intersil, factory housing made of 1.5mm sheet metal). It allowed me to explain the mysterious behavior in audio circuits many times. Definitely an important element of the electronics lab.
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  • #3 17160751
    tomal8403
    Level 13  
    Posts: 96
    Help: 8
    Rate: 9
    I have the same. With this amplitude potentiometer, it is a matter of cutting one track and soldering another pot with a wire.
    The device generates a DC component at the output, probably 1/2 of the supply voltage (I do not know what it is like in professional generators?).
    Besides, it is a fake of a real XR2206 which from what I remember can be powered up to 24V and the one above 12V gives unstable waveforms.
    There is a video on YouTube of how the guest improves this equipment (sine wave shape, some harmonics, I think, and the output voltage changed to lower).
  • #4 17160866
    marekzs3
    Level 19  
    Posts: 395
    Help: 31
    Rate: 35
    Which runs do your friend consider the most "Nasty"?
  • #5 17161214
    koko0
    Level 18  
    Posts: 266
    Help: 13
    Rate: 68
    My old G432 is probably behaving nicer ..... even though it is very old and it has never been calibrated :)
  • #6 17161301
    tomal8403
    Level 13  
    Posts: 96
    Help: 8
    Rate: 9
    Anyway, why does this DSO150 show Vpp and Vrms strangely?
    Vrms should be Vpp / (2sqr (2)).
  • #7 17161744
    2P
    Level 20  
    Posts: 345
    Help: 22
    Rate: 205
    These measurements are a bit stretched with an oscilloscope with a bandwidth of 200 kHz and sampling with 1 Msps. Here, at higher frequencies of triangular and rectangular signals, it is difficult to say whether the generator is wrong and the "oscilloscope" is measuring wrong.

    Measurement of a rectangle at low frequency and the "oscilloscope" set to AC mode - large error, practically disqualifying the entire measurement. What we see is the oscilloscope DC filter time constant, not the waveform generated. Same with the triangle for 2.5 Hz.
  • #8 17161767
    ^ToM^
    Level 42  
    Posts: 9048
    Help: 495
    Rate: 2929
    Good point, you have to put it on a normal oscilloscope, then you will see the quality of the waveform. However, I think that for the price of domestic courier delivery it will be a useful device. :D
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  • #9 17162079
    CMS
    VIP Meritorious for electroda.pl
    Posts: 8440
    Help: 256
    Rate: 2581
    2P wrote:
    Rectangle measurement at low frequency and "oscilloscope" set to AC mode - big error


    Tomorrow I will post new measurements. I actually shot a blunder.

    ^ToM^ wrote:
    you have to put it on a normal oscilloscope, then you will see the waveform quality.


    I will try to get some other camera and take pictures of oscillograms from a real oscilloscope.
  • #10 17163262
    seba_x
    Level 31  
    Posts: 2071
    Help: 29
    Rate: 112
    Take pictures of DSO150 and "real oscilloscope" just for comparison.
  • #11 17168676
    CMS
    VIP Meritorious for electroda.pl
    Posts: 8440
    Help: 256
    Rate: 2581
    I added some photos to the first post.
  • #12 17174279
    keseszel
    Level 26  
    Posts: 4087
    Help: 54
    Rate: 555
    Looking at the presented layout, one question arises. Is it still worth building generators on your own based on the structures presented in the years 1990 - 2000, or is it worth buying such a prefab? Price?
  • #13 17174426
    Anonymous
    Anonymous  
  • #14 17192482
    yogi009
    Level 43  
    Posts: 14662
    Help: 848
    Rate: 2646
    keseszel wrote:
    Is it still worth building generators on your own based on the structures presented in the years 1990 - 2000, or is it worth buying such a prefab? Price?


    Perhaps not everyone understands it, but the creation of any electronic project by hand is associated with the need to overcome many design and strictly electronic problems. In such a process, a person acquires knowledge at an alarming rate :-)
  • #15 17193680
    keseszel
    Level 26  
    Posts: 4087
    Help: 54
    Rate: 555
    Price .. Stop .. It's not about price, it's about quality. Is this Chinese enough to be used as a hobby?
  • #16 17195411
    NoweMillennium
    Level 17  
    Posts: 192
    Help: 23
    Rate: 10
    keseszel wrote:
    Price .. Stop .. It's not about price, it's about quality. Is this Chinese enough to be used as a hobby?

    Depends on what hobbies. Whether audio equipment or ultrasound or digital circuits.
  • #17 17198292
    yogi009
    Level 43  
    Posts: 14662
    Help: 848
    Rate: 2646
    NoweMillennium wrote:
    Depends on what hobbies. Whether audio equipment or ultrasound or digital circuits.


    A colleague is flying the frequency criterion, or some other?
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  • #18 21150457
    BrodaWawa
    Level 9  
    Posts: 9
    Rate: 2
    I just bought one from OLX.
    The net price is 24 plus their fees and shipping.
    The gentleman who sells this after the purchase asks if we want the device in parts or assembled. It will be useful for audio because in case of some short circuit I will burn the generator for 20 PLN and buy another one, meanwhile android generators have a smaller bandwidth. Also, it can be powered from a battery to test the amp (I'm building a tube amp from scratch and will be able to see what the waveforms look like, and the real frequency response with Toroids on the outputs. The way I've looked at it it's cool except at very high frequencies. My oscilloscope is a FNIRSI 1013D with custom Peco Scope software. I'm in the process of completing my workshop as I'm also going to refine my Mosfet SEs that I used to build and this penny toy will make my job a lot easier.
  • #19 21156311
    Aimeiz
    Level 16  
    Posts: 290
    Help: 2
    Rate: 20
    This kit on the XR2206 is nice, sine waveform better than from kits on the ICL8038. I have investigated all those available as DYI n Ali....
    It is a pity that at least a capacitive negative voltage converter was not added to the circuit, then there would be a generator with adjustable DC component. Such a patent is in one of the kits on the ICL8038.

    The circuit is recommended to be supplied with a voltage of 9 - 12V, but then at a setting close to the max amplitude it limits the vertices of the sine wave. Since the catalogue max supply voltage of the XR2206 is 26V, you can give a higher voltage without problems. Already at 15V it does not cut off the vertices at maximum amplitude. I fed 24V and then the results were best.
    You would need to add a power inverter to reflect the supply voltage to the negative side, then we will have a +/-12V supply and it will make a nice generator. The current consumption is about 25mA. Maybe someone knows of a simple tried and tested circuit?
    I found such a full generator circuit from an XR2206 powered by a symmetrical voltage, using probably all the functions of the IC.
    Circuit diagram of a function generator using XR2206 .
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Topic summary

✨ The discussion revolves around a simple function generator based on the XR2206 chip, available for self-assembly from sources like Aliexpress. Users share their experiences with the device, noting its ability to generate sinusoidal, triangular, and rectangular waveforms from 1Hz to 1MHz. Concerns are raised about the quality of the output, particularly regarding DC components and waveform stability at higher voltages. Some users suggest modifications to improve performance, such as using a higher supply voltage and adding a capacitive negative voltage converter. The conversation also touches on the educational value of building such devices versus purchasing pre-assembled units, with opinions divided on the practicality and cost-effectiveness of DIY projects.
Generated by the language model.

FAQ

TL;DR: For ~17 PLN you get a DIY XR2206 generator covering 1 Hz-1 MHz in five switchable bands and drawing about 25 mA [Elektroda, CMS, post #17160459][Elektroda, Aimeiz, post #21156311] "Definitely an important element" [Elektroda, yogi009, post #17160491]

Why it matters: a pocket-size, low-risk signal source that costs less than shipping a commercial unit.

Quick Facts

• Kit cost: approx. 17 PLN on AliExpress; local shops ask up to 90 PLN [Elektroda, CMS, post #17160459] • Waveforms: Sine & Triangle 0-3 Vpp (adjustable), Square 8 Vpp fixed at 9 V supply [Elektroda, CMS, post #17160459] • Frequency bands (jumper): 1-10 Hz, 10-100 Hz, 0.1-3 kHz, 3-65 kHz, 65 kHz-1 MHz [Elektroda, CMS, post #17160459] • Recommended supply: 9-12 V DC, 5.5 mm/2.5 mm center-positive jack [Elektroda, CMS, post #17160459] • Typical current draw: ~25 mA at 12 V [Elektroda, Aimeiz, post #21156311]

What exactly comes in the XR2206 kit?

The parcel includes a pre-etched PCB, all through-hole parts, acrylic enclosure panels, M3 screws, knobs, and jumpers [Elektroda, CMS, post #17160459] You must supply longer M3 screws or spacers if you want the board mounted after soldering, because the factory screws are too short once solder fillets add thickness [Elektroda, CMS, post #17160459] No power adapter or test leads are included.

How difficult is assembly for beginners?

Soldering is straightforward because every part is through-hole. Arrange parts by height, start with resistors and diodes, then capacitors, sockets, and finally the larger potentiometers and connectors [Elektroda, CMS, post #17160459] A beginner with a 30 W iron needs about 30 minutes.

Why does the amplitude knob work "backwards"?

The PCB routes the wiper to the opposite side of the potentiometer, so clockwise rotation attenuates instead of amplifying [Elektroda, CMS, post #17160459]

Can I fix the reversed amplitude control?

Yes. How-To (3 steps):
  1. Cut the PCB trace from the wiper to the wrong pad.
  2. Solder a small jumper wire from the wiper to the other outer pad.
  3. Optionally replace the pot with a front-access model for smoother feel [Elektroda, tomal8403, post #17160751]

Is there a DC offset on the output?

Yes. The generator sits at roughly half the supply voltage, about 4.5-6 V when powered from 9-12 V [Elektroda, tomal8403, post #17160751] Use a coupling capacitor or add a bipolar supply to eliminate this offset.

How accurate are the five frequency bands?

Observed upper limits are roughly double the printed values: up to 20 Hz in the first band and 200 Hz in the second [Elektroda, CMS, post #17160459] Expect ±100 % tolerance unless you swap timing capacitors.

Why do my high-frequency waveforms look ugly on DSO150?

The DSO150 bandwidth is 200 kHz with 1 Msps sampling, so anything above 100 kHz shows aliasing and rounded edges [Elektroda, 2P, post #17161744] A higher-bandwidth oscilloscope reveals cleaner signals within the generator’s limits.

What’s the current draw of the unit?

Measured consumption is about 25 mA at 24 V, which scales roughly linearly with voltage [Elektroda, Aimeiz, post #21156311] That is less than many smartphone chargers’ standby draw.

Is this generator good for audio work?

Yes. The 0-3 Vpp sine covers the entire audio band with low risk to pre-amp inputs. One reviewer said it “explained mysterious behavior in audio circuits many times” [Elektroda, yogi009, post #17160491]

What are the main drawbacks?

  1. Fixed 8 V square wave amplitude can overdrive logic.
  2. Reversed amplitude potentiometer.
  3. Significant DC offset.
  4. Light enclosure slips; add rubber feet [Elektroda, CMS, post #17160459] These are manageable for hobby use.

Is it worth building my own generator instead?

Vintage DIY designs teach more electronics, but cost more in parts than this 17 PLN kit. One member concluded: build for education, buy for price [Elektroda, Anonymous, post #17174426]

Can I add symmetrical ±12 V supply?

Yes. Add a charge-pump inverter such as ICL7660 to generate –12 V from +12 V, then split the rails. A forum schematic shows full XR2206 operation on ±12 V [Elektroda, Aimeiz, post #21156311]

What measurement mistake should I avoid?

Do not use AC-coupling when viewing low-frequency rectangles or triangles; the scope’s high-pass filter distorts the shape and amplitude, leading to false conclusions [Elektroda, 2P, post #17161744]

How stable is the square wave above 500 kHz?

Edge-case tests show severe rounding beyond 200 kHz and complete loss of symmetry near 1 MHz on both pocket and CRT scopes [Elektroda, CMS, post #17160459] The generator meets its spec only at lower ends of each band.
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