Author Topic: FeelTech/FeelElec FY8300S Quick Tear Down  (Read 4043 times)

0 Members and 2 Guests are viewing this topic.

Offline grizewald

  • Frequent Contributor
  • **
  • Posts: 515
  • Country: se
FeelTech/FeelElec FY8300S Quick Tear Down
« on: January 15, 2020, 03:10:18 pm »
Yesterday, I received a new FY8300S arbitrary signal generator. When unpacking it, the first thing I noticed was that there was something rattling around inside the case! So, regardless of breaking any warranty stickers, opening up the case and finding what was rattling around was the first priority before applying any power.

The case is great fun to take apart as the two ends now clip onto the main housing in four positions instead of two, so it turned out to be quite a battle. Thankfully, the tool marks on the plastic will be hidden once I put it back together. While I have everything in bits, I thought people might appreciate some tear down shots.



Everything looks very familiar from the FY6900. The same power supply, a very similar mainboard (re-spun to add the third output channel) and the same, unsafe grounding modification.

The rattling turned out to be one of the screws which hold the fan to the rear panel:



When I went to remove the other three screws, I immediately understood why the first one had fallen out. The screws are way too short for the job and as they have conical starts (being self tapping) hardly grip the mounting holes at all.

The fan itself is a 12V fan which seems to be running on 5V. It's certainly quiet and runs all the time when the machine is plugged in unless it is turned off via the switch on the mains input socket. It blows air from the case to the outside, pulling air into the case via the slots in the lower half, which are all nicely free of flashing. The wires to the fan sit on top of the wires carrying mains voltage from the mains input socket.

Here's the main PCB:



FeelTech couldn't be bothered re-spinning the PCB again to add a socket for the fan and have simply tacked the fan's power wires to a nearby regulator (which is now under a tiny heatsink which it shares with another regulator).



As the wires to the fan are just flapping around in the breeze, it's only a matter of time before they snap off where they are soldered to the regulator.

Finally, here's the power supply board. It still has a glass fuse. On mine, the ceramic capacitor just to the right of the fuse is actually fitted. I've seen pictures of the supply in the FY6900 and that capacitor often seems to be missing for some reason.



There are a few things that need doing before I put it all back together:

1. Fix the mains input socket wiring to properly insulate and strain relieve all the connections.
2. Return the number of grounding wires between the power supply and main PCB to two instead of one.
3. Secure the fan power wires and fit screws of the correct length to hold the fan securely.
4. Provide a properly insulated resistive connection between PE and power supply ground.
5. Put some heatsink compound between the output op-amps and their heatsink.
6. The soldering on the NOS relays seems to have been done after the board was assembled. I guess nobody bothered cleaning the pins of the relays before soldering as some of the joints are hardly making a connection (as far as I can see through the layer of flux which wasn't cleaned off the board after soldering the relays and output BNC connectors).

Given that FeelTech have seen the criticisms of the power connector connections and the grounding arrangement from the FY6900, it's disappointing to see them repeating the same mistakes in the latest design. The way the fan has been added is amateurish to say the least.
 
« Last Edit: January 19, 2020, 08:19:41 pm by grizewald »
  Lord of Sealand
 
The following users thanked this post: don.r, enut11, Jacon, PKTKS, edigi, alextwin007, duckduck

Offline PKTKS

  • Frequent Contributor
  • **
  • Posts: 632
  • Country: br
Re: FeelTech FY8300S Quick Tear Down
« Reply #1 on: January 15, 2020, 03:25:15 pm »

no surprises.

For the  price? still a good bargain.

bottom line: I don't care unless totally bricked if
I can open the housing and fix easy tidbits.

Simple design -  fair price - some fun
no worries if i can ditch the seal and disregard warranty

Can not say that for instruments of other price class


Paul
 

Offline grizewald

  • Frequent Contributor
  • **
  • Posts: 515
  • Country: se
Re: FeelTech FY8300S Quick Tear Down
« Reply #2 on: January 15, 2020, 03:29:22 pm »
I've certainly no arguments with the fact that it represents good value, but it really doesn't cost much to do the mains input and wiring in a safe manner.

  Lord of Sealand
 

Offline PKTKS

  • Frequent Contributor
  • **
  • Posts: 632
  • Country: br
Re: FeelTech FY8300S Quick Tear Down
« Reply #3 on: January 15, 2020, 03:37:16 pm »
I've certainly no arguments with the fact that it represents good value, but it really doesn't cost much to do the mains input and wiring in a safe manner.

yep and  certainly some fun improving the noisy smps with a linear one

for my use? I don't even bother that much.
 Just some fast waves here and there without hassle...

Paul
 

Offline don.r

  • Frequent Contributor
  • **
  • Posts: 730
  • Country: ca
Re: FeelTech FY8300S Quick Tear Down
« Reply #4 on: January 15, 2020, 05:17:50 pm »
Doesn't appear to be a huge improvement over the 6900 given the price difference. Mods will still have to be done to make it safe as well.
 

Offline Gregg

  • Frequent Contributor
  • **
  • Posts: 831
  • Country: us
Re: FeelTech FY8300S Quick Tear Down
« Reply #5 on: January 15, 2020, 07:09:42 pm »
There is a lot of room to put a linear power supply inside compared to the FY6600.  If my FY6600 dies, I may consider swapping the linear power supply I made into a FY8300 but I don't have any need for the third output.
 

Offline rhb

  • Super Contributor
  • ***
  • Posts: 3083
  • Country: us
Re: FeelTech FY8300S Quick Tear Down
« Reply #6 on: January 16, 2020, 02:39:50 am »
Sigh....  Why am I not surprised.

Given the almost non-existent customer support from F***Tech/F***Elec it's par for the course.

I bought a Keysight 33622A 120 MHz AWG out of frustration with the FY6600 which was at the time borked by V 3.0 FW.   Even a used unit from Keysight's ebay store was 35x the FY6600.  But it is quite simply incredible.  Less than 1 ps jitter and able to generate ~10 ns pulses with a nice Gaussian shape.

As for value, I'll try to find time to make some comparisons between the FY6600 and the 33622A.  The harmonic performance of the F***Tech is actually *very* good at low output levels.

In my campaign to get F***Tech to provide relief to forum members with borked V 3.0 units  I sent F***Tech a bunch of photos of the two units on my 8560A that were so similar you could not tell the two apart with the promise to post a more complete comparison if they took care of the forum members.  It took almost a year, though one forum member was himself part of the problem by not responding to emails about shipping info.

I had threatened to launch a campaign of complaints about the lack of safety approvals, so I find it very interesting that German customs seems to not be letting the F***Elec products into the country.  IIRC I did eventually make a complaint to the US product safety commission, but did not single out F***Tech. 

The thing I find rather intriguing at this point is forum members have put so much engineering time into correcting deficiencies that a competitor could build a better clone with relatively little effort.  With first rate customer support they could easily charge 50% more than F***Tech.

Reg
 
The following users thanked this post: rf-loop

Offline nctnico

  • Super Contributor
  • ***
  • Posts: 20117
  • Country: nl
    • NCT Developments
Re: FeelTech FY8300S Quick Tear Down
« Reply #7 on: January 16, 2020, 06:49:03 am »
Doesn't appear to be a huge improvement over the 6900 given the price difference. Mods will still have to be done to make it safe as well.
Well, there aren't any safety issues from a technical point of view. The mains wiring is rated for mains voltage use and the creepage / clearances are OK too.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline luma

  • Regular Contributor
  • *
  • Posts: 89
  • Country: us
Re: FeelTech FY8300S Quick Tear Down
« Reply #8 on: January 16, 2020, 11:33:15 am »
[...]
I had threatened to launch a campaign of complaints about the lack of safety approvals, so I find it very interesting that German customs seems to not be letting the F***Elec products into the country.  IIRC I did eventually make a complaint to the US product safety commission, but did not single out F***Tech. 

The thing I find rather intriguing at this point is forum members have put so much engineering time into correcting deficiencies that a competitor could build a better clone with relatively little effort.

I think more intriguing is the length of effort you will go to to try and prevent the rest of us from being able to import cheap test equipment.  We're buying $100 AWGs, nobody is harboring any ideas about them being as safe or stable as a $5000+ unit from Keysight.
 
The following users thanked this post: Jacon

Offline grizewald

  • Frequent Contributor
  • **
  • Posts: 515
  • Country: se
Re: FeelTech FY8300S Quick Tear Down
« Reply #9 on: January 16, 2020, 11:57:59 am »
Doesn't appear to be a huge improvement over the 6900 given the price difference. Mods will still have to be done to make it safe as well.
Well, there aren't any safety issues from a technical point of view. The mains wiring is rated for mains voltage use and the creepage / clearances are OK too.

Using a wire with low voltage DC insulation to link ground to protective earth while at the same time allowing that wire to come into contact with the switched mode power supply's HV components is a significant and genuine safety problem. As is the fact that the fan wires were also touching HV parts of the equipment.
I can't imagine having directly soldered mains wiring with no strain relief being allowed either.
  Lord of Sealand
 

Offline nctnico

  • Super Contributor
  • ***
  • Posts: 20117
  • Country: nl
    • NCT Developments
Re: FeelTech FY8300S Quick Tear Down
« Reply #10 on: January 16, 2020, 01:51:24 pm »
Doesn't appear to be a huge improvement over the 6900 given the price difference. Mods will still have to be done to make it safe as well.
Well, there aren't any safety issues from a technical point of view. The mains wiring is rated for mains voltage use and the creepage / clearances are OK too.
Using a wire with low voltage DC insulation to link ground to protective earth while at the same time allowing that wire to come into contact with the switched mode power supply's HV components is a significant and genuine safety problem.
But it isn't. Look more carefully at teardown videos of other devices and you can see the wire used for the ground has a 300V rating.
Quote
I can't imagine having directly soldered mains wiring with no strain relief being allowed either.
It seems the wires are soldered through the holes of the inlet. AFAIK there is no requirement to have strain reliefs on internal wiring. I agree it would be nicer to have a piece of heatshrink over the pars with mains voltages but OTOH it makes it difficult to inspect the solder joints.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline grizewald

  • Frequent Contributor
  • **
  • Posts: 515
  • Country: se
Re: FeelTech FY8300S Quick Tear Down
« Reply #11 on: January 16, 2020, 02:17:37 pm »
But it isn't. Look more carefully at teardown videos of other devices and you can see the wire used for the ground has a 300V rating.

My mistake. Looking closely at the wire which goes to the earth, it does indeed have a 300V rating. But that's less than it should have to be safe against the rectified mains voltage which is present in parts of the switched mode supply.

I'll still be reworking mine to make the wiring acceptable to my criteria. 
  Lord of Sealand
 

Offline CDaniel

  • Frequent Contributor
  • **
  • Posts: 349
  • Country: ro
Re: FeelTech FY8300S Quick Tear Down
« Reply #12 on: January 16, 2020, 08:11:46 pm »
And after teardown , can you check the jitter for square wave ? One of the issues with FY6600 ... if this is resolved than is not just an expensive toy and could worth the money
Power supply and other deficiences can be corrected , but sloppy firmware not .
« Last Edit: January 16, 2020, 08:14:52 pm by CDaniel »
 

Offline ArthurDent

  • Super Contributor
  • ***
  • Posts: 1193
  • Country: us
Re: FeelTech FY8300S Quick Tear Down
« Reply #13 on: January 17, 2020, 03:47:24 am »

Here's the main PCB:




One thing I noticed was that the oscillator has been changed from the 50Mhz one used in the FY6X00 models to the common 10Mhz, making it much easier to modify it from using the crappy little oscillator to a much higher stability OCXO. 
 
The following users thanked this post: don.r, Jacon, Bad_Driver

Offline don.r

  • Frequent Contributor
  • **
  • Posts: 730
  • Country: ca
Re: FeelTech FY8300S Quick Tear Down
« Reply #14 on: January 17, 2020, 06:12:45 am »
Now THAT'S an improvement I can admire.  :-+
 

Offline FeelElec

  • Contributor
  • Posts: 41
  • Country: cn
Re: FeelTech FY8300S Quick Tear Down
« Reply #15 on: January 17, 2020, 09:17:15 am »
Dear customer, we are very apologize for the trouble and thanks for your suggestion. We could accept your suggestion and replace the screws. If there is any problem with the product, please feel free to contact us.
Email: service@feelelec.com


FeelElec
 

Offline nctnico

  • Super Contributor
  • ***
  • Posts: 20117
  • Country: nl
    • NCT Developments
Re: FeelTech FY8300S Quick Tear Down
« Reply #16 on: January 17, 2020, 10:48:24 am »
I spot a solder bridge in the close up image of the oscillator!
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline grizewald

  • Frequent Contributor
  • **
  • Posts: 515
  • Country: se
Re: FeelTech FY8300S Quick Tear Down
« Reply #17 on: January 17, 2020, 10:51:00 am »
Dear customer, we are very apologize for the trouble and thanks for your suggestion. We could accept your suggestion and replace the screws. If there is any problem with the product, please feel free to contact us.
Email: service@feelelec.com


FeelElec

It would be a good idea as they currently fall out during shipping. If I hadn't noticed something rattling, who knows what a loose screw could have done!
  Lord of Sealand
 

Offline grizewald

  • Frequent Contributor
  • **
  • Posts: 515
  • Country: se
Re: FeelTech FY8300S Quick Tear Down
« Reply #18 on: January 17, 2020, 11:02:59 am »
I spot a solder bridge in the close up image of the oscillator!

If you mean the 20 pin chip just above the unpopulated 10 pin header, it's actually an HC245 bus transceiver which does the level conversion for the TTL outputs. It seems to be an intentional link between pins 17 and 18 as it was done after the PCB was assembled.
  Lord of Sealand
 
The following users thanked this post: nctnico

Offline grizewald

  • Frequent Contributor
  • **
  • Posts: 515
  • Country: se
Re: FeelTech FY8300S Quick Tear Down
« Reply #19 on: January 17, 2020, 11:10:39 am »
One thing I noticed was that the oscillator has been changed from the 50Mhz one used in the FY6X00 models to the common 10Mhz, making it much easier to modify it from using the crappy little oscillator to a much higher stability OCXO.

Well spotted! When I quickly looked at the output, I seem to remember a 10MHz sine wave being about 9.999991MHz when measured with my GPSDO timebased counter. Using a 10MHz crystal really does make it simple to add an external reference input.
  Lord of Sealand
 

Offline rhb

  • Super Contributor
  • ***
  • Posts: 3083
  • Country: us
Re: FeelTech FY8300S Quick Tear Down
« Reply #20 on: January 17, 2020, 07:24:10 pm »
That *almost* makes it worth getting one.
 

Offline grizewald

  • Frequent Contributor
  • **
  • Posts: 515
  • Country: se
Re: FeelTech FY8300S Quick Tear Down
« Reply #21 on: January 17, 2020, 10:34:49 pm »
And after teardown , can you check the jitter for square wave ? One of the issues with FY6600 ... if this is resolved than is not just an expensive toy and could worth the money
Power supply and other deficiences can be corrected , but sloppy firmware not .

Square wave at 1.32566Mhz. Solid as a rock!

  Lord of Sealand
 

Offline nctnico

  • Super Contributor
  • ***
  • Posts: 20117
  • Country: nl
    • NCT Developments
Re: FeelTech FY8300S Quick Tear Down
« Reply #22 on: January 17, 2020, 11:18:07 pm »
You need to look at multiple periods! A square wave is difficult for every DDS based waveform generator (and most digital ones are) unless it has a special mode for generating square waves (*). The problem is that a square wave period always needs to be a multiple of sample clocks. If the requested frequency isn't dividable by the sample clock then some periods will be longer and others shorter which shows up as jitter.

The older Siglent SDG1000 series for example had extra circuitry to turn a sine wave into a square wave to mitigate this problem (which wasn't without issues though).
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline grizewald

  • Frequent Contributor
  • **
  • Posts: 515
  • Country: se
Re: FeelTech FY8300S Quick Tear Down
« Reply #23 on: January 18, 2020, 12:48:29 am »
My mistake.

Here's a 9.32566MHz square wave. Triggering on the leading edge with persistence set to 10 seconds.



I'd be getting a thick trailing edge if there was jitter wouldn't i?
  Lord of Sealand
 

Offline grizewald

  • Frequent Contributor
  • **
  • Posts: 515
  • Country: se
Re: FeelTech FY8300S Quick Tear Down
« Reply #24 on: January 18, 2020, 12:52:16 am »
It's a different story if you wanted to use the generator's sync output though.

Ch1 is the same square wave, Ch2 is the sync output from the generator and the 'scope's trigger source.

  Lord of Sealand
 
The following users thanked this post: NoisyBoy


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf