FeelTech FY6800 60MHz Signal Generator / Counter Review
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- Опубліковано 15 лип 2024
- Covers everything but the rear connectors and the PC stuff …
↓↓↓ Complete description, time index and links below ↓↓↓
A while ago I found myself in need of a signal generator (link below). Not having one I resigned to using the test output of my oscilloscope and conditioned the signal with a few parts. But now I’ve bought the latest and greatest from Banggood.
I put that brand spanking new Feeltech FY6800 through its paces. And I go into great detail about it. If you endure that one hour long video you’ll be able to operate that thing, know its limitations and are aware of its quirks.
Introduction …
00:00 Introduction - it’s going to be a very long video
01:11 In the box - the unit, various cables and a guarantee card
01:47 Comparison - to the FY6600 and Ruideng/JunCe JDS6600
04:02 Mechanical - lightweight and a wee bit flimsy
Handling …
04:57 Switching - power and channels on and off
06:59 Waveforms - more than enough
10:22 Frequency - setting it is straight forward
11:44 Amplitude - same as frequency
11:56 Offset - same as above
13:28 Duty cycle - same as above
13:48 Phase shift - same as above
14:14 System menu - not quite intuitive
Bandwidth …
15:08 Sine - up to 60MHz, with some jitter above 10MHz
18:18 Square - up to 10MHz, maybe 20MHz, some jitter above 10MHz
19:59 Triangle - up to 10MHz, maybe 20MHz, some jitter above 10MHz
20:31 Saw tooth - up to 10MHz, maybe 20MHz, some jitter above 10MHz
Parameters …
22:20 Amplitude - maximum 20Vpp
23:16 Offset - ±10V, but the output is limited to ±10V
24:49 Duty cycle - 0.001% to 99.999%, with oddities at 0% and 100%
25:48 Phase shift - 0.000° to 359.999° absolute, not channel relative
Advanced …
28:30 Modulation - everything you’ll ever need, at least I’ll ever need
35:05 VCO - frequency, amplitude, offset and duty cycle voltage controlled
39:14 Sweep - same as VCO, but timer controlled
Counter …
42:10 Basics - in fact very basic and with a delicate input, but it works
45:48 Principle - of operation, probably counting zero crossings
System menu …
48:04 Settings - menu with information and basic settings
49:51 Configurations - loading and saving them, lots of them
Conclusions …
54:05 General - works, (almost) meets its specs, good value
56:33 DC offset - it’s annoying, but maybe it can be corrected
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This review is a big help for this rooke, thanks for taking the time.
You're welcome!
excellent review , detail and explanations were very helpful in working out how to use this unit that has just arrived thankyou for your effort and time
Thank you and you're welcome!
I just received this scope today and began playing with it. I think they may have fixed the offset issue you describe at 23:16 of your video. Great video. I followed long and got 300% more out of it than the manual.
Thanks - and you're welcome! Chinese manuals are notoriously ... brief 😉 That is if they're actually somewhat useful. In many cases they are just outright funny.
Very useful and complete review - thanks!
You're welcome!
Excellent review/tutorial. Thank you, much appreciated.
You're welcome!
Thank you for this superb review Robert, its very professionally done. You solved my problem of not hearing the internal AM modulation of my carrier because I wasn't leaving it in MOD mode! I just got the KKMoon FY6900-60 mhz unit which is very very similar. The only other kind of oddball thing is the "OK" button changes the units which took me an hour to figure out. Anyway, I subscribed to your channel. I will check out your other stuff soon! Dave from Phoenix AZ!
Thank you for the praise - and you're welcome! I'm always happy when people get something out of my videos.
BRILLIANT. Exactly what I needed to know. Thank you Robert.
You're welcome 🙂
Thank jou for taking time and making this clear video!
You're welcome!
Thanks for this detailed review. I don't have enough electronics knowledge to fully understand, but it seems to me that a device like this is an incredible value (current eBay retail price ~ US $140)! It makes me wonder how much better a $3000 device of this type would be, but I guess people who make a living in EE probably know what works best for them.
You're welcome! And yes, the unit has an incredible functionality for the price. But it also has some limitations, especially in regards to the output stage/amplifier (see ua-cam.com/video/u6zQM3S556A/v-deo.html ). For a few thousand dollars more you get a higher frequency precision/stability, lower noise/distortion, an output stage/amplifier that's worth its name, and trigger functionality.
Nice review. Thanks. I'd be very interested in your suggested video about trimming away the DC offset, as I have noticed the same problem on my unit but am not brave enough to take it apart on my own. Anyway, I agree with your opinion: this device is incredible value for money, despite the UI quirks. I could only have dreamed of having something like this 25 years ago.
You're welcome. I'd planned to make the trimming video as soon as that DC offset got in the way of something I needed to do with the function generator (which it hasn't up to now). Maybe I'm able to speed up things. No promises ;-)
This is exactly what i needed thank you
You're welcome!
Very well explained. Thanks.
Thanks for the praise! And you're welcome!
Very good video.. 👍
Thank you very much 🙂
Great video , thank you very much!
Thanks for the praise! And you're very welcome!
Excellent video thank you, I watched it all. I still have one question though.
Do you know what the min sweep rate is?
I have an older Feeltech unit that won't go finer than a 1Hz/s sweep rate.
My SDG1025 will sweep as fine as .02Hz/s.
You're welcome!Just according to the possible settings (haven't tested that with an oscilloscope yet): You can set the sweep period (time) between 999.99s and 0.01s. The upper and lower frequency can be set both between 60MHz (probably not very usable) and 0.1Hz. The DSS in that thing works down to 1uHz (Micro Hertz). So I assume the finest sweep you can achieve in theory is 0.1Hz/999.99s, or about 0.0001Hz/s / 0.1mHz/s / 100uHz/s. But I wouldn't put my money on that ;-)
A square wave needs at least the 3rd and 5th harmonics to look even remotely squarish. So the 20MHz square wave will need 100MHz of bandwidth to show the 5th harmonic. Your scope is already down ~3dB at 50MHz and will cut a lot more at 100. You cannot judge the generator based on what the scope shows.
Now, it is quite possible, even likely, that the generator has a 60MHz bandwidth limitation, but this test is inconclusive.
You're absolutely right about the test regarding the square wave bandwidth being inconclusive, because the bandwidth of the scope is too small. My bad!
@@robertssmorgasbord Go ahead and Riglol your scope to get the free 100MHz upgrade along the other nice add-ons! :)
Thank you for the in depth review, this comes in very handy since I am in the game for a frequency generator - currently trying to decide between the FY6800 and Rigol DP812.
@@robertssmorgasbord well first off all you should terminate with 50 ohms. With a 200mhz scope I still see a 50% decline in amplitude. BTW you can also measure with a simple diode peak rectifier and a multimeter. Nevertheless the -6db decline at 60MHz is because of a lack of sampling. The 250Ms give just 4 sampling points.
@@frozenfrogz Meanwhile I updated my Rigol to 100MHz ;-) Curiously the 100MHz option is no longer officially available from Rigol. And you're welcome (sorry for the late reply, somehow your comment slipped through the UA-cam cracks).
@@LutzSchafer I respectfully disagree that "you should terminate with 50 ohms". It's perfectly OK to take measurements on a 50Ohm BNC output with a probe adapter and an oscilloscope probe. A 50Ohm termination on the oscilloscope input is needed only when you're using 50Ohm BNC cable (to avoid reflections etc). And of course, terminating a 50Ohm output with 50Ohm you will see a 50% decreased amplitude.
That aside I find the idea that the sampling rate is the culprit most intriguing - there's some food for thought!
Very well done review, It's nice the way you started out showing Rival models, in the same price range,,, as this is how things are shown on E-Bay, amazon etc... The high frequency limits can be restrained by load impedance, cables and your limited 50Mhz scope band width as pointed out by Jacques... But yes the FY6800 looks like vary, vary good bang for the price... Is the video long?, No, not for showing us a good review of a complicated test instrument... As the FY6800 has just come out, they use a FPGA, so some of the things you pointed out can be changed quickly in there firm ware later, and FeelTech should heed your concerns.. Good for you Robert and FeelTech...
Thanks Don! I really appreciate these apt and to the point comments from you and the others. Now, if somebody at FeelTech would actually watch the video ... ;-)
Oh they will,,,, I suspect your review will be a go to before I buy kind of thing by middle of 2019, There marketing should, send you a new one, with those easy to update fixes that were clearly seen as frustrating. Then you can issue an update...
That would be nice and one can dream :-) However, in a UA-cam search for "feeltech fy6800" my video is at 5th place with 632 views while the 1st place has 7.434 views. Granted, the video at the 4th place with 1.447 views is just 15 minutes long, so it can hardly be an extended review, and at the 3rd place is a Russian video with 1.029 views. Still, I won't get my hopes up just yet ;-)
Excelente explicación !!!!!!
Thank you very much!
Thanks for the comprehensive review.
Between this and FY6600 and FY6900 which one do you recommend (assuming the 60MHz version of all)?
I don't see any specific difference in their specs other than FY6900 having slightly higher maximum pick to pick value (up to 24 volts for lower frequencies). But I don't know why the ratings for that in Amazon is less than, for example, FY6600.
I have neither bought nor reviewed the FY6600, so I can only give you the two reasons why I bought the FY6800 instead of the FY6600: 1. The FY6600 has real chincy membrane keys, while the FY6800/FY6900 has somewhat better rubber keys. 2. The FY6600 does not have the signal/BNC ground referenced to mains ground like the FY6800/FY6900 (or any mains powered oscilloscope).
@@robertssmorgasbord
Thanks for the info.
@@a000ab You're welcome!
Hi! Is it possible to receive sound modulation thru USB cable to the PC?
For what purpose need rear four BNC connectors and TLL port?
thanks
Nope, it's not possible to get any signals through the USB cable to the PC. The USB port is purely for controlling the FY6800.
Regarding the rear BNC connectors, they do exactly what there labels are saying. Trig/FSK/ASK/PSK IN: trigger input, frequency/amplitude/phase shift modulation input. VCO IN 0-5V: voltage controlled oscillator input. SYNC OUT: synchronization output. SYNC IN: synchronization input. For a more extensive use of these inputs see the video "Poor Man’s “Bode Plot” with FY6800 Signal Generator and Oscilloscope" ua-cam.com/video/ydJcsw4tD6I/v-deo.html .
Regarding the TTL OUT see the user manual: en.feelelec.com/index.php?case=archive&act=show&aid=64
Do you know if you can use the frequency counter to measure rf field, through connecting an antenna or some other way?
You definitely can't use the frequency counter input for that. It needs a signal with at least 1.5V amplitude and has (according to the manual) an impedance of (just) 100Ohm.
Hi Robert, excellent video, quick question, I want to use this to align FM and AM CB radios so under 30 MHz, I need it to output a modulated FM signal with a 1khz tone, can it do this? is there a limit? 1mv minimum is ok because I will reduce this with a step attenuator.
Thanks for a great video.
Well, that's a coincidence! I just tried to get out a 1mV 10Hz wave from that unit and it's noisy as hell! So I definitely would go with a attenuator (possible 1000 : 1). 1 kHz FM modulation shouldn't be a problem at all and 30 MHz is also kinda possible with that unit. But don't expect any wonders in regards to signal quality from that cheap Chinese box! See also my other video "FeelTech FY6800 60MHz Signal Generator Review Addendum II (Output Stage)": ua-cam.com/video/u6zQM3S556A/v-deo.html
@@robertssmorgasbord yes i looking for signal generator as well for cb radio 1k hhz 30 % modulation and read frequency of 100 mhz.also rigol DG1022U IS ANOTHER OPTION
@@Robalo844 Well, I guess a 30% 1kHz AM modulation with a 27MHz (CB) carrier wave is doable with the FY6800. But as I mentioned above: Don't expect a great signal quality! The FY6800's counter is specified up to 100MHz, but I personally wouldn't trust it to do accurate measurements at 100MHz. The Rigol DG1022 counter is specified up to 200MHz, so no problems there - I trust Rigol's specifications much more than I trust FeelTech's ;-) However the DG1022 only goes up to a 20MHz (sine wave), so no CB signal generation with it. The DB1022U is specified up to 25MHz (sine wave), so it also falls short of the CB's 27MHz. If you want to go with Rigol I would go with the DG1032Z (30MHz sine wave) or DG1062Z (60MHz sine wave) - counter on both is specified for up to 200MHz.
@@robertssmorgasbord how about the fy6900 60 MHz.thank you for all the information Happy new year,and goog luck
@@Robalo844 The FY6900 is basically a slightly tweaked FY6800 in a pimped up case - at least that's my personal opinion ;-) The important thing here (for you) is that the counter of the FY6900, like the one of the FY9800, is specified up to 100Mhz.
Very helpful, thanks for your time. Any way for it to provide a "start sweep" output pulse to sync external device to SOS?
You're welcome! Regarding your question: It has a BNC labeled "SYNC OUT" at the back, but I have no idea if it provides a "start sweep" at this output. Give me a few until after the weekend and I will test that.
I had a little time before I had to leave for work. So to answer your question: No (unfortunately). The SYNC OUT connector at the back just provides the square wave equivalent of whatever is coming out of the output at the front, not a single pulse at the start of a sweep. I'll upload a short two minute video on Sunday.
FY6800 is able to adjust amplitudes for both channels on the same time when you're visulizing them realtime on osciloscope, or is doing it for one channel only?
because on mine it wont allow doing it on both(like a stereo mode on audio, sort of saying), but swicth adjustings on one of them at the time(like mono)
it allows only to select either the cannel one, or the channel two for adjusting the amplitude or frequency, i cant do it for both on the same time...like i said
is this how suppose to be, or is there a problem?
i mean having 2 channels should not allow it for them to be set realtime on each one, and both on the same time?
The FY6800 offers modulation on channel 1 only. You will have to spend much more if you want a 2-channel signal generator that can do modulation on both channels. E.g. a RIGOL Rigol DG1022Z will set you back about 400 bucks.
Hallo! Many thanks for the review. I have a maybe stupid question. Since the 6800 has a IEC connector, I suppose that the the outer part of the BNC is reference to the mains earth. Is that correct? This could be dangerous if connected to the oscilloscope, since it's BNC are also reference to mains earth right?
Vielen lieben Dank im voraus :)
You're welcome! And yes, BNC ground is referenced to mains earth.
@@robertssmorgasbord Thank you very much for your reply, appreciate that! In this case it should be dangerous to connect the generator directly to the scope, right? Or do I miss something? Maybe the 20Vp-p output of the generator isn't enough to blast the probe of the scope?
BTW, really nice channel, I'll subscribe after this comment.
@@sesvid Nah, with 20Vpp you won't blow up any standard bench oscilloscope. Most, like my Rigol, are good for 300Vrms.
The grounding is a non-issue here, since you simply connect ground (generator) to ground (scope) to ground (mains earth - twice, once through the generator and once through the scope).
Word of caution: The reference of a scope's BNC ground to mains earth can become an issue when you measure a mains appliance (e.g. try to repair your TV). Connect the ground of your probe to something inside the appliance connected to mains live/phase (basically shorting main live/phase to mains ground through your oscilloscope via the probe) and you'll get a big bang ;-)
@@robertssmorgasbord Great! Many thanks again for your help. Everything is clear now. And please keep making videos on UA-cam. I like the way you speak with no hurry 👍
sesvid _
Any suggestions on the back panel TTL pins labeled RX TX?
RX/TX is a serial interface (5V level) for controlling the generator. I myself haven't tested it, but it seems other people are using it (e.g. hamprojects.wordpress.com/2018/10/21/fy-6800-generator-as-beacon/ ).
The USB port provides the same serial interface (serial via USB). The PC software for the generator uses it to, well, control the generator from a PC. And no, I did not test the PC software.
At 45:48 --> For DC coupling of counter you must input the signal to the Trig in on the rear (the first bnc...) instead of the regular one..
Thank you very much for the info! That's not something you'll find in the manual. How did you find out about that trick?
@@robertssmorgasbord in the manual (version 1.0, the only one I guess....), at page 31. Ya, is hard to read all due some "artistic" translation :)).....
@@robertssmorgasbord the manual of the "new" 6900...
@@SalvoMorina You're right! In version 1.1 (yes, you can download a version 1.1 from en.feeltech.net) of the FY6800 it clearly states on page 30: "When the DC coupling mode is selected, signal should be inputted from Trig IN terminal.". That's pretty clear. I'm such a dummy :-)
@@robertssmorgasbord you are not a dummy at all...
Hi Robert ! Could you please make a video on how to sweep an amplifier? I bought an FY 6900 (similar to the FY 6800). I am trying to get the sweep signal with a synchronization signal to have a steady signal on the scope, but I cannot get the sync pulse in synchronism with the sweep signal. Please explain the generator configuration as well as the interconnections. Thank you so much for you help. Regards, RJM
Hi René-Jean, ah yes, synchronizing a sweep with a scope ... six month ago I had a lengthy discussion with Nemo in the comment section of the addendum to this video ( ua-cam.com/video/TDv0kfaotyQ/v-deo.html ). Unfortunately, to this day I don't know, respectively, haven't verified if that is possible at all with the FY6800/FY6900. Maybe I should give it a try. But no promises here, it will be at least a few weeks until I come around doing that. Regards Robert
Hi René-Jean, a video describing how to sync a frequency sweep with an FY6800 to an oscilloscope - at the end I even sweep an audio amplifier ;-) - is out now: ua-cam.com/video/ydJcsw4tD6I/v-deo.html
When I use the sweep feature, it seems to come out in "chunks" instead of linearly.. For example if I'm testing a filter, when I sweep through the filter, it comes out in amplitude "blocks" and not a nice straight/curve..it's weird.
I haven't observed that myself, but I can totally picture it doing that. Generating a smooth sweep is not trivial (cheap to implement). My best guess is the unit simply changes the output frequency in discrete steps ("chunks") when sweeping. That would be the easiest (cheapest) way to implement a sweep.
@@robertssmorgasbord I think it might be because of the speed of sweep - I was trying to sweep in like .01 seconds. Maybe it just can't do it that fast linearly
@@researchandbuild1751 Have you tested it with a longer sweep time or a smaller frequency range? Does the problem disappear then?
@@robertssmorgasbord i think it seems to work dedent on slower sweep times like 1 second or so. I havent tested it much there because that would require a digital scope to see the long waveform and i only have an analog scope right now
@@researchandbuild1751 Well, maybe I put that on my list of of videos to make then.
Can anybody please tell me whether the FY6800 would be accurate enough for calibration and adjustment of an analog oscilloscope from the ealry 1970s? Or should I save and buy a more expensive unit? I have read a lot about this unit on the forums and here on YT - YT6800's problems with noise, jitter and other things.
At the moment I can afford to spend around 300 Euros / dollars (260 UK pounds) at most on a Uni-T, Voltcraft, Rigol, Sigilent or Owon (or maybe you can recommend something around my price point). I would like the most accurate and precise instrument I can afford at the moment - I want to be able to calibrate other instruments and devices with it. Thank you in advance!
Simple, but I guess kinda frustrating answer for you: Out of the box definitely no!
These FeelTech units are not very well calibrated themselves when they come out of the factory (offset, symmetry, amplitude). However, you can - if you have already an oscilloscope you trust (and/or a good multimeter) - calibrate them yourself within a few or a few dozen mV: ua-cam.com/video/O9JXn-9mAcs/v-deo.html
Frequency accuracy shouldn't be a problem as long as your expectations are within reasons (it uses a non temperature stabilized quartz as time base).
If you have a properly calibrated unit (offset, symmetry, amplitude) you can use it within reason to calibrate other stuff.
That said, what are your requirements? E.g. do you want to calibrate to 5%, 2%, 1%, 0.5% or even 0.2% amplitude accuracy (an 8-bit digital scope has already an +/-1 LBS error of about 0.4%)?
One more thing, I definitely wouldn't use its square wave output at higher frequencies (beyond a few MHz) to calibrate frequency compensation stuff. There is too much "dirt" on the raising an falling edges.
While the frequency settings are accurate enough, the voltage settings are poor. The actual output voltage will vary with frequency.
is it possible to use this device to align an AM radio - so for example to inject a modulated IF - say 455 - into the radio?
Yes, I don't see why not. AM frequencies (carrier) and audio frequencies (modulation) are well within the capabilities of that signal generator.
@@robertssmorgasbord Many thanks. I sat down and had a play. These are the steps I took:
Ensured both channels were active; set channel 1 to 455 KHz and outputting a sine wave; set channel 2 to an audible frequency - I chose 600Hz; selected the MOD button and chose AM modulation ensuring the modulation source was set to Channel 2; used the BNC to alligator clip leads to connect from Channel 1 to the grid of the converter tube in the tube radio I wanted to check. The 600Hz audio signal was heard from the radio and I could tune the IFTs to peak them.
@@German_byte You're welcome 🙂
Very well done.
I am wondering if it can output From 0-30mhz carrier frequency with a 300Hz-600Hz modulation??
A 30MHz sine carrier wave shouldn't be any problem. An AM modulation of that carrier with 300Hz to 600Hz should also possible. A FM modulation with 300Hz to 600Hz might be a bit tricky.
@@robertssmorgasbord I just need it to do alignment on a grundig satellite 2000 shortwave radio.sounds like the job then. Thank you.
@@ralph9987 You're welcome!
@@ralph9987 I have exactly the same area of application for the FY and therefore fortunately found this video. I am also thinking about buying it and I am quite confident that it works. At the latest when the device is here I will know. Several Grundig Concert-Boys, Satellites and Ocean-Boys will be happy about new alignment :-))
@@robertssmorgasbord BTW: Great video! Thanks a lot. Finally a detailed demo of the modulation options what I was looking for since longer time.
Can a modulation frequentie tone be generated, like for example, send a signal at 200khz with a modulation tone like 600hz, so that you can hear it a radio for example. So, with this tone generated, you can adjust then the frequenties of the radio.
Well, yes. Generating a 200kHz carrier sine wave modulated (presumably frequency modulated - FM) with a 600Hz signal shouldn't be any problem with this unit. And yes, the 200kHz carrier is stable enough to calibrate a radio.
@@robertssmorgasbord Ok, thx, but for the 200kHz i need AM (amplitude modulation). So, probably that will also work :)
@@ronnyverminck2741 AM, of course! My bad! Who would want FM modulation on a 200kHz carrier. And yes, that works too with this unit.
@@robertssmorgasbord i have received my FY6900 (probably nearly similar to the FY6800) but i can't seem to find how to add a audible tone, like 600Hz tone, on a 200kHz wave. I can set to AM, but don't know how to set the tone. I want to recalibrate my radio and want a tone that i can hear from the speakers. Thx
ok, i found it. I just need to set the 600Hz in the channel 2 and use Ch2 as the source. This works fine.
Hello!
It is possible to get a 25% duty for square signal where inside the 25% interval we have like 25 pulses ?
(Example: 100 micro seconds, 75 microseconds off, 25 microseconds on but inside these 25 microseconds I need lets say 25 pulses of a square signal)
Hi! Not really. I guess you could set up a 75us/25us square wave on channel 2 and use that to amplitude modulate a 0.5us/0.5us square wave on channel 1. But syncing the amplitude modulation to avoid cutting off / extending the first / last 0.5us/0.5us is not possible. Alternatively you could upload a custom waveform (8192 points). That should work better.
@@robertssmorgasbord thank you for your reply, really appreciated it!
@@robertssmorgasbord please can i can you about the second mentioned option (the custom waveform) how i can do it ? And shall i need a special function generator or any function generator can have this feature ? Sorry to bother you but i am not that expert in function generators
@@raghebsamrout8205 Most function generators but the really cheap ones support custom waveforms. I know that the FY6800 does. You need to install the FY6800 software on your PC. There you can either draw a waveform or you can load a waveform from a file (don't ask me about the file format, but it should be easy enough to find out, since you can also save waveforms to a file) and upload it to the unit.
@@raghebsamrout8205 You're welcome!
25:48 Phase shift - 0.000° to 359.999° absolute, not channel relative... Perhaps 180 degrees to start for both channels. 165 not so bad a representation of -15 degrees? Thanks for the video
Good idea to start with 180°! And you're welcome!
Thank you. Very well done. 73 N8VY Doug
I thank you for the praise! Coming from an amateur radio operator that means a lot.
can you sweep both channels simultaneously? forgive me if it was in the video, I just skipped through.
Nope, sweep works on channel 1 only.
no adapter for oscilloscope probe ?
Nah, had to roll my own ;-) But I plan to buy some adapters or probes that come with adapters. I also plan to buy some 50Ohm BNC feed through terminators.
I ordered the 100 MHz version it was out of stock so I had to wait a few weeks for it to be made. I got it today and when I hooked it up and turned it on it was DOA does not turn on at all.
I'm assuming you ordered the 100MHz FY6900 model (the FY6800 is available up to 60MHz only). It really must hurt to shell out over 100 bucks and then the unit is DOA :-( I whish you the best of luck getting your money back or a replacement unit!
did you get your money back or a replacement?
@@dany_2945 after contacting BangGood more than a dozen times on their customer service web site with email and never got a reply. I filed a claim with PayPal and got more run around then they said that the claim was closed and they had decided in favor of the seller. I called to voice my opinion and this time I got someone that spoke English and explained my case to her. She looked it up and came back and said that the way it was handled was bullshit and that she reopened the claim issued me a full refund and closed the claim. I still never heard anything from BangGood.
@@dwoaks1 I'm sorry to hear that, but at least you've got your money back. But it's kinda what I've expect from BangGood (and in extension AliExpress) - not that I had any personal experiences in that regard, it's just my guts talking. I'm sure there are reputable sellers on both platforms, but for most the "customer experience" ends as soon as they got the money. I've tried a while ago to get a firmware update for my Andonstar AD407 microscope from Andonstar - never heard back from them.
@@dwoaks1 i wanted to buy few things from banggood but i really don't trust it with more expensive items, do you think it's better to buy from amazon.de sellers? i am from Romania where shipping takes some time even if it's from Germany, i am trying to buy stuff from Europe at least (banggood has shipping from CZ republic for some items)
If you are at maximum amplitude and then apply an offset, clipping is what I would expect, looks perfectly normal to me, they don't call it maximum amplitude for nothing.
Well, I can definitely understand your point of view. But I would have liked to have seen at least a "Waveform clipped!" warning, if I input settings that will produce a clipped waveform. Otherwise you always have to do the math by yourself.
hi , can this unit generate the 2 tones necessary for ssb linearity?
cheers
I don't see why not. You have of course to mix the two outputs of the FY6800 with some external circuitry. However, why buy a $100 function generator and build an external mixer, if a simple $5 circuit that already includes a mixer can do the job: dk7ih.de/a-simple-2-tone-generator-for-testing-the-linearity-of-ssb-transmitters/
@@robertssmorgasbord cheers m8..i already have this 6800 for S9 signal receiver setting (attenuated) sensitivity..just dont really understand the circuit required to mix the 2 tones..
@@andrewverran3498 Have a look at this: electronics.stackexchange.com/questions/103435/naively-mixing-two-or-perhaps-more-audio-signals
The resistors should have the same value as the impedance of your input. You can enhance that circuit by putting capacitors in series/front of the resistors to remove any DC offset. The capacitors values should be roughly C = 10uF/R[kOhm]. So e.g. for 10kOhm 10uF/10 = 1uF and for 4.7kOhm 10uF/4.7kOhm = 2.1uF. It's not that critical.
@@robertssmorgasbord I think you are missing the point..please refer to W2EAW video on 2 tone SSB linearity..can the FY6800 do what his Signal generator is doing with of course the added Summer Circuit?
I have a fy6800 why would I want to build what you have suggested?
@@suzanneserich9852 I guess you referring to this video: ua-cam.com/video/3DxBg6h4Fc8/v-deo.html (#8: Two-tone test of SSB transmitter output). I'm no radio amateur, but I can't see any reason why that shouldn't work with a FY6800. You just need a very simple two channel signal generator for that test. And the FY6800 is just that.
Where did you buy your test probes?
The probes came with the Rigol oscilloscope. The BNC-to-probe adapters are home-made from BNC connectors (just rolled up some copper foil inside them until it was a snug fit for the probes' ground shield; the tip of my probes fortunately fit perfectly into the solder lugs for the BNC center conductor). The BNC cable came with the signal generator.
@@robertssmorgasbord Thanks very much. I wont spend time searching then :-) I'll make some myself as you did.
Could you make some videos on how to use the function generator in IRL ( with different electrical setups or constructions) eg. sweep, pulse, trigger, sync. I understand the functions, but have no idea on how to use them IRL.
@@Infinitesap You're welcome! If you find the self-made BNC-to-probe adapters to flimsy for your taste: Buy a cheap oscilloscope probe set that contain such an adapter (e.g. www.batronix.com/shop/measurement/probes/Testec-TT-LF-312.html ). And in this video you can see the FY6800 in IRL action: "Poor Man’s “Bode Plot” with FY6800 Signal Generator and Oscilloscope" ua-cam.com/video/ydJcsw4tD6I/v-deo.html .
The Rigol DS1054Z can't properly display square waves over a few Mhz, its bandwidth is too low. You need at least a 200MHz unit to see 25MHz square waves.
Also, I've noticed you plugged the oscilloscope probes directly in the BNC connectors; please don't do that. Beyond being mechanically damaging to the connectors, that is not how you measure 50ohm output generators. You need straight 50ohm coaxial cable and 50ohm terminations at the oscilloscope input.
You are absolutely right regarding the measurement of the square waves! My bad! See also the excellent thread started by Jacques Gilbert in January 2019 (currently 1 year and 4 month ago) as well as the comment of ELCRONICS
from January 2020 (currently 4 month ago) down below.
But I did not plug my oscilloscope probes directly into the BNC connectors of the function generator! It might look like it, but I really didn't. I used some homemade probe to BNC adapters (visible from 00:47 to 01:45) 😉 They are really just BNC connectors with one side stuffed with some rolled up copper sheet (for ground connection) and rolled up isolation material to get the diameter intended for coax cable down to the diameters of my probes 😄 And yes, people complained about them, so nowadays I do own proper probe to BNC adapters.
Regarding having to measure 50Ohm outputs with properly 50Ohm terminated BNC cables: Yes and no. It's totally legit to measure the 50Ohm BNC output of a function generator directly with an oscilloscope probe at these frequencies and power levels (doesn't work for HF power amplifiers though - they'd die because of reflected HF energy). All you're missing is the 50% voltage drop because of the 50Ohm termination. However, you're measuring the output without any significant load, so I might have missed some quirks of the output stage.
can you explain a little about this "50ohm terminations at the oscilloscope input"
I just got one of this FY6900 (60mhz variant) here from Europe (74USD delivered) and from a noob-standpoint, I'm trying to learn as I go while also trying to take my precautions, with the use of my new SDS AWG FY6900 60mhz connected directly to the Scope via the BNC cable that came with it, I reckon the cable is 50ohm BNC to BNC cable..
are this "50ohm terminations at the oscilloscope input" mainly referred to when somebody are using the actual scope probe, or is it some termination I need to take on some of the other ground connected BNC ports.
I have looked online and can see those "50ohm terminations" looks like a dead-end, and makes me wonder if that is like an end-plug.
I'm new to the scene and simply trying to find common ground while exploring. i.imgur.com/k29uitf.jpg
With the Fy6900 ua-cam.com/video/B2YNG1DNXv4/v-deo.html
@@JAKOB1977 Any RF transmission system has a source impedance (the FY6900 in this case), a transmission line characteristic impedance (the coaxial cable) and a termination impedance (oscilloscope input impedance). In case one of these don't match with the others (eg. all 50ohm), part of the RF wave will "bounce" back along the transmission line, combine with the incident wave at certain phase angles (depending on the length of the transmission line, velocity factor etc) and distort waveform / generate harmonics etc. The main issue is many/most oscilloscopes have a high input impedance (1Mohm + 13pF for example) which creates a complete mismatch in the transmission system, so 50ohm terminations are employed at the scope inputs to properly match the rest of the system. These terminations are either "pass-through" barrel type or a T junction that connects to the incoming coaxial, the scope input and a 50-ohm BNC termination. Rigol explains it in this video: ua-cam.com/video/Fg63gIrmQ2k/v-deo.html
@@JAKOB1977 & Razvan: Perfectly explained! Got nothing to add. And a big thank you to Razvan for answering that question.
@@JAKOB1977 Where did you find the FY6900 for $74 ?
Can it produce scalar wave using bifilar coil????
Well, I guess you could feed a bifilar coil with it (1W max - assuming the coil has a matched impedance of 50Ohm for the frequency used). But I have to admit that I don't know what "scalar waves" are. Thus I'm unable to answer your question!!!!
@@robertssmorgasbord That's a term from quantum physics (some extension of Maxwell's equations), often abused from the "free energy sub-culture community" for their BS claims...
@@LutzSchafer Your theoretical background is so much deeper than mine ... I just guessed from the use of "scalar wave" in conjunction with "bifilar coil" that this was some BS question :-)
Also, anything “scalar” is also a big red flag for woo and BS. Both “bifilar cool” and “scalar wave” in a single sentence is quite an achievement!
With small signals below 50mV, interference pulses (peaks) occur. Does anyone have a solution for the problem?
Not me 😞 I think there are some enhancement projects out there using a redesigned power supply with linear regulators to make the output signal cleaner. And at 50mV you certainly need a very clean power supply.
How about adding some attenuators to the output? A 20dB attenuator should cut the output by a factor of 100, so you could set the generator to produce a 5V signal, and 50mV signal would come out of the attenuator.
@@drtidrow Yes, you can do it that way. I get a clean signal even below 50mV. 20dB attenuates the voltage by a factor of 10, not 100. But that's enough. Important: Do not connect the Attenator directly to the FY6800, as everything around it is subject to interference and the Attenator will receive part of it. Better connect the Attenator at the other end of the line, away from the FY6800. Thank you for the great idea.
@@anyuser100 Yeah, I always get the power and voltage reduction factor mixed up.
I do like the idea of using a linear power supply in place of the switch-mode one to get rid of the switching noise, though there's so much crap in the air and on the lines from all the other ones around that it may not matter that much.
@@anyuser100 10dB is 10 and 20dB is 100 and 30dB is a 1000 as Robert said.
Your Rigol, as a 50mhz scope, won't be able to resolve anything but a sine wave around that frequency, by nyquist sampling theorem. So I don't think there's much value in looking at waveform shapes near the top of its range. To see a good square wave, the scope needs to see the original frequency, plus quite a few of its 3x harmonics correctly. So for 25Mhz square wave, it needs to resolve 25Mhz + 75Mhz + 125Mhz + 175Mhz etc. Therefore, its square wave might be ****, but you couldn't use that scope to judge it.
You're right, some of the waveform distortions are caused by my oscilloscopes bandwidth limit. BTW: I have the 100MHz upgrade installed on my Rigol DS1054Z (it has the same internals as the DS1104Z), but that's still a little low for a 25MHz square wave.
someone can tell what is the 14BIT on the genereator
The digital-analog-converter (DAC) is 14 bit - the signals are generated digitally and then converted to analog signals.
@@robertssmorgasbord ok so the the signal i guess is not good for calibrating a 24 bit audio device do you have in mind the best device for calibrating AD converters ?
@@fstopspictures8834 First a disclaimer: I have no experience with HiFi electronics. That said: You'll have a hard time finding a signal generator with a 24 bit DAC - I know of none. So why not go with a low distortion analog sine wave generator? E.g.: www.analog.com/en/design-center/reference-designs/circuit-collections/lt1028-lt1055-lt1004-super-low-distortion-variable-sine-wave-oscillator.html
People are designing circuit for this waw thats sound legit thank you bro
@@fstopspictures8834 Happy I could help, even if it wasn't my area of expertise :-)
Hello Robert, sorry if this a dupe, I replied to your question with my phone but now I cant find it? Anyways, to answer your question; often times one does not need "high end" test equipment to perform test. I would have given both my nads to have this little generator 30yrs ago lol oh, get a amateur radio licence so you can join the fun! 73 N8AUM
Hi N8AUM, you've posted your reply on the second part of the review ;-) There I answered: "Hi N8AUM, yes, compared to what was available 30 years ago I'm definitely complaining on a very high level about the output stage of that FY6800 in this video :-) And let's not forget how cheap that thing is."
@@robertssmorgasbord I don't need one but I just purchased one LoL
@@vidasvv Good on you :-) It's definitely fun to play with ;-)
Lots of artifacts come from your scope.
I wouldn't say lots, but definitely some ;-) There is already a discussion further down about the bandwidth of my scope being too low for measuring the square waves at maximum frequency.
270 degrees = - 90 degrees - any negative phase shift is possible
Indeed, it is. It's just not very comfortable/intuitive.
Incorrect testing when you test wave shape 21:06.
- You are using 50Mhz bandwitdth DSO ,so you are lossing a lot of harmonic of squre wave ,saw wave...
You can not know the real wave shape.
- fy6800 60Mhz bandwitdth ,that mean hight frequency (harmonic) was reduce by internal filter. (saw wave shape was normaly distort at near maximum bandwitdth )
- 21:53 is not spike ,it is effect by lossing hamanic by bandwitdth limit.
In telecomunication system bandwitdth limit is nessesory .
If you want a perfect shape at 10 Mhz, you need 1GHz DSO and 1GHz signal generator.
You are absolutely right! My bad! See also the excellent thread started by Jacques Gilbert in January 2019 (currently 11 month ago) down below.
I’m going to secure a brick to the insides of my unit to weigh it down
Yeah, the unit is a bit lightweight, isn't it? But why use a brick? Glue some copper plates to the inside of the enclosure, connect them to ground, and you have your additional weight plus shielding ;-)
@@robertssmorgasbord Well, Copper is expensive, bricks are cheap, LOL. Maybe a good compromise would be sheet lead (Plumbum).
@@aerofart That's in fact a great idea! You can actually get self-adhesive sheet lead (1.25mm thick)! Just don't forget to wash your hands after you worked with the stuff ;-) Plus, by using lead you also make that signal generator radiation resistant :-)
My sweep doesn't work :(
Wow, messed with sweep for the last hour and right after I posted that I decided to turn off and on (hard power) the FY6600 and now my sweep works great lol.
@@kurchak Well, I guess at that price level the occasional small hiccup is to be expected 😒 Anyway, you managed to get it working again 😄 I find the most annoying thing about such glitches is the time you have to waste on them 😡
Sorry to hear that! Hope you find a solution ...
@@robertssmorgasbord true! I also almost returned my brand new SDS1205XE because it was "acting funny"..... Turned out I just forgot to recalibrate my probes after I switched everything to 10X 🤣
@@kurchak Did something similar with an OWON once: It was off, sitting on the shelf for quite a while. Then, some day I got it out to do some timing measurements. But the timings I measured were totally nonsensical - until I self-calibrated the scope. Turns out the different timebases/oscillators/PLLs inside that thing need some calibration from time to time (pun intended) too 😲 I always though only the amplifiers/attenuators/ADCs need calibration. Well, one never stops learning 😉
Hello Robert, just wondered if the outputs of this device float above ground potential due to the switch mode power supply. A voltage of approx. 90v @ 50Hz was measured by another reviewer of a similar device (ua-cam.com/video/9o5MzTOzZo4/v-deo.html)?
Hi Mervyn, no they don't. The outputs of the FY6800 are referenced / connected to mains earth. Like the Daniu FY3224S it has a switch mode power supply, but unlike it the FY6800 has an IEC mains connector with a mains earth connection, and that is connected to the low voltage side ground of its switch mode power supply.
@@robertssmorgasbord Hi Robert, thanks for your reply and thank you for your effort in making these videos, they are very informative.
@@mervynposnett3248 You're welcome - and thank you for the praise!
offset for maximum amplitude is normal !
That might be so, but 85mV offset is kind of annoying. However, I should really measure the DC offset at lower amplitudes too (and I will if I don't forget it).
just wanted to say thank you for this awesome video very informative.
I am glad that they added grounding to the output shields However the jitter on all waves seems to be an inherent problem with the unit, as there was a Russian guy (ua-cam.com/video/ZxxFSSdewHw/v-deo.html) whom tried to change the power supply and the caps and the internal pots and still could not get rid of that jitter
You're welcome! And thanks for the info about the jitter.
the root of cause of the high jitter in this generator is FPGA firmware. It implements low quality NCO (numerically controlled oscillator) with high jitter, so you cannot fix it with hardware mods. Because this is software problem.
@@qrp7381 ahhh that explains allot thanks for the up[date such a pity ...but i guess you get what you pay for something i'm still learning. so if its software related do you think one day there may be a patch from the dev to fix this issue. or will there be some amazing coder out there that will tackle this as a varsity theses . :>
@@fred9za I think the jitter can be significantly reduced with rewritten firmware, but I doubt the manufacturer will not deal with this, because sales already good enough. I hear some guys from eevblog tried to write custom firmware, but it seems that it's not done yet. The jitter appears when XTAL frequency is divided with fractional divider. Due to low NCO quality, the mistake is too high in that case and leads to high jitter. If you try to setup frequency which can be obtaned from XTAL frequency with integer divider, the jitter will gone. For example, 5 MHz will works with no jitter.
The firmware is just doesn't care about divide error and this is the reason why high jitter appears.
@@qrp7381 Well, maybe, just maybe, FeelTech will offer an firmware upgrade at some point. That is if there's enough "space" in the FPGA left to implement a better NCO. But chances are they used the smallest, cheapest FPGA possible to do the job with no "room" left for improvements. So I wouldn't get my hopes up.
Modulation on mine don't work.
Sorry to hear that. Have you tried to return your unit? I myself have never tried to return anything I bought on Banggood or Aliexpress, so I have no experience in that regard. But at that price it might be worth trying to return it.
Works on mine perfectly, send it back for replacement, if you don't you have nothing to complain about.
I had bad keysight scope (meh quality control), sent it back underwarantee.
Watched too many war movies, a German accent sounds so sinister. "We have ways to make that function generator talk."
Herr Sattahip, we did not appreciate your inappropriate comment on the GREAT GERMAN ACCENT! Cheers ;-)
Slow, really slooow!
it is to look at least at 1.5x...
Anyway, good review. apart from the connection of those probes...
Thanks - I guess :-) And yes, I'm not the fastest (English) speaker. But I strive to get faster ;-) BTW I meanwhile bought a set of probes with BNC adapers ;-)
@@robertssmorgasbord don't worry, it's better! I'm Italian and prefer simple and slow English!
GJ 👍
@@janbe71 :-)
В общем, нихрена не понятно
Но дизайн похож
"In general, shit is not clear"? I'm sorry, but Google translate couldn't make sense of that :-( Извините, но Google переводчик не может понять это :-(
Wie wär's mal auf Deutsch? Oder ist Deutsch verboten?
Deutsch ist nicht verboten, wird aber nur von 160 Millionen (Mutter- und Zweitsprache) verstanden. Bei English sind es 1,5 Milliarden (Mutter- und Zweitsprache).