Author Topic: FeelTech FY6600 60MHz 2-Ch VCO Function Arbitrary Waveform Signal Generator  (Read 287410 times)

0 Members and 3 Guests are viewing this topic.

Offline DC1MC

  • Super Contributor
  • ***
  • Posts: 1027
  • Country: de
Hi
What is the state of the bluepill sofware for Fy6600?

I was thinking to make a version for a STM32 discovery board.
Any chance to get hold of the source code?

Thanks

Sadly freemen67 suddenly disappeared in the middle of a conversation and never posted or even accessed the forum since then, I really fear for the worst  :(.

 DC1MC
 

Offline fisafisa

  • Regular Contributor
  • *
  • Posts: 72
  • Country: es
We all have bad periods in our life.
Hope he is fine.

Filippo
 

Offline Johnny B Good

  • Frequent Contributor
  • **
  • Posts: 311
  • Country: gb
 Well, it's been three weeks since that radio ham rally event in Blackpool that I mentioned in my last marathon posting about the voltage tests on my PS board modifications. I'm afraid to report that it failed to live up to my hopes regarding my desire to accumulate OCXOs and the other bits 'n' bobs I was hoping to acquire in face to face deals with the various traders who attend such events.

 It wasn't a complete wash out since I did manage to get my hands on a 13MHz CQE branded OCXO for just 4 quid that I'd spotted amongst a rather random collection of stuff laid out on one of the trader's tables. It wasn't the desired 10MHz but, for a mere 4 quid, I was confident I'd be able to use it as a 13MHz sourced 10MHz clock supply (it was an OCXO - the only OCXO I'd managed to spot for sale- and was only 4 quid!  :) ).

 Typically, whenever I enquired about OCXOs (and other items) that any trader looked like they might normally hold stock of, yet unconscionably failed to have on display, the answer was often, "Yes, I have them back at the shop but I didn't bother to bring any due to limited space in the van." or similar such lame excuse.

 I do appreciate the limited carrying capacity of their transport (and the strain on their backs in carting such stock from the van to the table(s) and then back again) but, for an event like this, especially these days, I'd have thought such items as high precision frequency components like OCXOs and RRIO opamps and PLL and divider chips and so on would have been high priority stock items on such outings.

 I can only presume that this is a sad reflection of the state of the hobby now being one of cheque book solutions to the advancement in building up the contents of a modern day radio shack rather than via technical expertise in home brewing or DIY modification of existing commercial amateur radio kit as was once the case several decades past.  :(

 Anyway, all that sadness aside, I did manage to grab hold of a pitifully few other bits 'n' bobs before having to admit defeat and call it a day. Needless to say, I failed to find even a suitable PSU enclosure to re-home the FY6600's PS board into with most of my purchases being more along the lines of speculative "might prove useful" items such as a couple of 10MHz crystals which did prove surprisingly useful in creating a crude filter to clean up the PPS 10MHz output from my u-blox M8N based GPS module I'd bought a few months earlier.

 That 13MHz OCXO that I'd managed to snag so cheaply didn't have any information regarding its pin out or any hint of whether it was a 5 or 12 volt part (the trader professed a total ignorance as to any such information - probably why he was happy to accept my offer of just 4 quid for its purchase). The best I could do in my on line searches for any sort of a data sheet was a single page image of a 13MHz 12 volt Vectron clone. I got the pin out details ok but I had my doubts as to whether my CQE version was, likewise, a 12 volt part. Discretion proved the best part of valour in my subsequent voltage probing tests from which I was eventually able to conclude that, rather unusually, it was a 5 volt rather than the more common 12 volt part.

 I lashed up a breadboarded circuit to generate a 10MHz signal via a doubler to feed a divide by 13 with 26 MHz which then fed the resulting 2MHz into a second clock multiplier chip to generate the required 10MHz (the 3N502's minimum input clock frequency being 2MHz, hence the multiply by 2, divide by 13, with a multiply by 5 sequence to convert 13MHz into a perfect 10MHz square wave signal).

 Since this was all powered from a single 5 volt rail, I was tempted to use this as a replacement to my original TCXO upgrade but although the peak current demand by the OCXO alone of 280mA (reducing to around the 170mA mark once up to temperature) looked likely to be just within the limits of the FY6600's 5v PSU rail, I rather thought the additional 70 to 90mA from the multiplier, divider, multiplier chips would break this particular camel's back.

 Further searches for a more specific data sheet for my 5 volt 13MHz CQE OCXO eventually disclosed a cheap source of 10MHz CQE clones at just £4.99 each from the following supplier:

<https://www.ebay.co.uk/itm/CQE-CRYSTAL-OSCILLATOR-10MHz-REDUCED-TO-CLEAR/253081992039?hash=item3aecdcbb67:g:x1gAAOSw~qNZh2rl>

<https://tinyurl.com/y6pl2xvk>

 I initially bought three of them just over a week ago before committing to another four to provide myself with a "Lifetime's Supply" at a bargain basement price. I hadn't wanted to disperse the news of my bargain of the century find for fear of creating a stock depleting demand on the supply. Having now secured my supply, I'm only too happy to now spread the good news as a "Public Service Announcement" to all and sundry here.  :)

 Be aware though, the stock is slightly mis-described as "unused NOS" when in fact on close inspection (of the last four examples in my case) they're obviously used stock - two of them clearly had remnants of a through plated hole clinging onto a pin or two. All seven have proved to be in excellent working condition and showed no sign of the more usual cosmetics typical of some Chinese recovered offerings which often hint that they'd been dislodged from their PCBs with a hammer before being slung into a skip.

 Quite frankly, why the trader in this case felt it worth the risk of damaging his credibility by claiming "Unused NOS" in the description on an item he could easily have sold for twice the asking price even when correctly described as "Used stock", is a mystery to me. Force of habit, maybe? Anyhow, they seem to be well worth taking a chance on as a dirt cheap bargain basement 10MHz 12v OCXO clone of the Vectron units described in that photocopied data sheet page I posted in my u-blox M8N GPS module thread. The only discrepancy being the 4Vpp ac coupled sine wave output versus the 4Vpp squarewave output described in the Vectron data sheet.

 In spite of the complication of adding an extra 12v 300mA smpsu board (recovered from a small wallwart), I decided to utilise one of these 10MHz OCXOs to upgrade my FY6600 instead of the original 13MHz 5 volt only unit. The extra power demand by the 10MHz OCXO and its smpsu once at temperature is just a mere 1.3W which additional thermal loading is no longer an issue once the signal generator has been blessed with a small cooling fan as it has been for the past 5 months with my own generator (for anyone contemplating modifications to their FY6600/6800s, a cooling fan must take the highest priority - I used a 50mm square by 10mm deep 12v fan powered off the 5v rail in my case, very quiet yet so very effective at dispersing the heat build up).

 Going the "12v OCXO plus additional 12v smpsu add-on" route proves a very effective way to apply such an upgrade. Unlike Arthur Dent, I chose to connect the little 12v 300mA smpsu board directly to the mains inlet socket connections so I could keep the OCXO powered up whilst plugged into a mains supply even when the whole generator is switched off by its back panel on/off switch rather than burn the additional 5 watts of standby power it consumes when placed into standby mode on the front panel button.

 Also, unlike Arthur's use of a change over switch arrangement with the external 10MHz reference input socket he'd fitted to his unit, I plan on using the "injection locking" technique to synchronise the internal 10MHz OCXO to an external GPSDO 10MHz reference sans the complication of a change-over switch and the risk of disruptive glitches which could confuse the FPGA logic into a locked up state.

 The only problem with this 'neat idea'(tm) despite my on line researches, being that I need to experimentally figure out an injection locking circuit to achieve this goal. It's a well document technique (often discussed in the context of avoiding unwanted injection locking of XOs of any type to external interference from close in frequency clock sources - so, "How hard can it be?").

 Unfortunately,  I haven't been able to find any example circuits with real world OCXOs so I'm on my own with regard to solving this particular mystery. I started a new thread a couple of days ago entitled:- " Injection locking the 10Mhz OCXO to external reference (upgrading a FY6600)" but so far, haven't had any 'takers' despite the attached images having been viewed 14 and 13 times so far. Don't worry, I do plan on eventually presenting a report on this new tangential approach to adding an external 10MHz reference to the FY6600/6800 AWGs we all seem to have a love/hate relationship with. I don't know how long it will take to develop a working solution so don't wait with bated breath on this.

 In the meantime (in the tradition of my recent posts into other threads), here are a couple of attached photos for those who may not have seen them already. The first shows my collection of OCXOs, sans the one fitted into the FY6600, and the second shows the effect of my crude two crystal and 4K7R 'T' 10MHz filtering of the GPS's PPS signal on the 'scope traces when comparing the 10MHz output from the signal generator.

 There's, hopefully, just enough resolution to reveal sufficient detail in what's going on. The picture is a fair representation of the reduction of the non-integer division induced jitter of a 48MHz clock down to a 10MHz sine wave although it can't show its mitigation of the sawtooth jitter to something less jittery and more wavery in character which makes attempts at calibrating a 10MHz OCXO to within 100ppt a little less fraught.

 Unfortunately, such filtering is no substitute for a disciplined OCXO since the filtered raw PPS signal still contains the +/- 10 to 12ns variations reflected in the Deviation Map window in the u-centre app which typically shows excursions of 3 to 4 metres from a median position (which itself wanders around). It's this effect which makes the matter of getting the OCXO calibrated to better than 50ppt a matter of pure dumb luck. Clearly, there's no substitute for a GPSDO when it comes to sub ppb precision in calibrating OCXOs. Anyway, enjoy the pictures!  :)

JBG
« Last Edit: May 21, 2019, 12:27:52 am by Johnny B Good »
 


Offline bitseeker

  • Super Contributor
  • ***
  • Posts: 8434
  • Country: us
  • Lots of engineer-tweakable parts inside!
Interesting mimic of the old Rigol case design. It looks like the "bumpers" are just part of the plastic enclosure.
I TEA.
 

Online wasyoungonce

  • Frequent Contributor
  • **
  • Posts: 424
  • Country: au
Wonder what the DIL socket on the back is?
I'd forget my Head if it wasn't screwed on!
 

Offline beanflying

  • Super Contributor
  • ***
  • Posts: 5057
  • Country: au
  • Toys so very many Toys.
Wonder what the DIL socket on the back is?

The 6600 has a TTL port so 99.99% sure it will be the same.
Coffee, Food, R/C and electronics nerd in no particular order :)
 

Online wasyoungonce

  • Frequent Contributor
  • **
  • Posts: 424
  • Country: au
Thanks tried to get manual but it’s not uploaded yet
I'd forget my Head if it wasn't screwed on!
 

Offline bitseeker

  • Super Contributor
  • ***
  • Posts: 8434
  • Country: us
  • Lots of engineer-tweakable parts inside!
Yeah, looked like a TTL port in the Banggood pic, though it's pretty hard to read the raised white lettering on the white back panel. I guess ink is expensive. ;D
I TEA.
 

Offline Jacon

  • Contributor
  • Posts: 33
  • Country: pl
Thanks tried to get manual but it’s not uploaded yet
This link:
http://myosuploads3.banggood.com/products/20190606/20190606070659FY6900SeriesUsersManualV1.0.doc
worked perfectly for me, yesterday & today.

It's a MS Word docu, titled:

FY6900 Series Fully Numerical Control
Dual Channel Function/Arbitrary Waveform Generator
User’s Manual
Rev1.0     May,2019
 
The following users thanked this post: Johnny B Good

Online wasyoungonce

  • Frequent Contributor
  • **
  • Posts: 424
  • Country: au
Ahhh ok thanks tried to open it on iPhone. Wot an idiot! :palm:
I'd forget my Head if it wasn't screwed on!
 

Offline DC1MC

  • Super Contributor
  • ***
  • Posts: 1027
  • Country: de
Oooohh, look at the big fat 3-pole power connector on the back  :-DD, some lessons were learned  :-+ !!! But where is the software ?
 

Offline beanflying

  • Super Contributor
  • ***
  • Posts: 5057
  • Country: au
  • Toys so very many Toys.
You are assuming the big fat Earth pin is connected inside the box  :-DD  :horse:
Coffee, Food, R/C and electronics nerd in no particular order :)
 

Offline Jacon

  • Contributor
  • Posts: 33
  • Country: pl
.... But where is the software ?
When the item will be available, I assume.

Today they are in pre-order state(21 pcs reserved already), which should be processed in ten days...
 

Offline Noy

  • Regular Contributor
  • *
  • Posts: 115
  • Country: de
Any difference to FY6800 already known?
 

Offline soundtec

  • Regular Contributor
  • *
  • Posts: 194
  • Country: ie
'Rigol' sprung to mind when I saw the 6900 too.

Maybe we will finally see a more usable version of the software from  FT soon ,

Just looking at the new manual now ,not sure if theres much difference , but hard to know for sure .
Maybe it has an improved clock ,output op amps, better supply ,and more accuracy across different output voltage ranges.

I see a few posts around in here relating to developing a software for these series of machines , basically external control ,
Id quite like a way of generating a series of audio tones for testing in conjunction with 'REW FFT' software to look at %THD .
I was able to get reliable sine waves at certain frequencies down to a THD of around 0.003% , less favourable frequencies show upto around the specified 0.5% of distortion .
 

Offline Cliff Matthews

  • Supporter
  • ****
  • Posts: 1810
  • Country: ca
    • General Repair and Support
For those thinking a PDF might have been a better idea..  :-/O
 
The following users thanked this post: grizewald, Johnny B Good

Offline bdunham7

  • Frequent Contributor
  • **
  • Posts: 389
  • Country: us
The only differences I see are the increased max Vp-p of 24V and the elimination of the 100uV step in the amplitude setting.  I guess we'll wait for a teardown to see what they've done for the power supply this time--but I'm not expecting much!  Meanwhile, the prices of the FY6600-60MHz have hit $40 on eBay, so if you like the idea of multiple synced units, now is the time to pick some up.
 

Offline Johnny B Good

  • Frequent Contributor
  • **
  • Posts: 311
  • Country: gb
You are assuming the big fat Earth pin is connected inside the box  :-DD  :horse:

 They've most likely repeated the mistake they made with the FY6800 and created a hard connection to the BNC grounds.  If they're still monitoring this thread, then they may well have used a link to the PE via a 1KR to 10KR "drain resistor" to squash the half live touch voltage down from 90 to 110vac  to 50 to 500mV 50Hz on a 240v supply without introducing the evil effect of an unwanted mains routed ground loop, a feature which hadn't cursed the earlier FY6600 (but at some risk of ESD damage to any devices under test).

 It will be interesting to see whether they fixed their skoolboy howler with the earthing of the FY6800 where they not only created an earth loop issue but had also, to add insult to injury, hijacked one of the two ground returns in the PSU to main board ribbon cable connector on account it was just the right length to reach the PE tag on the mains socket.

 Assuming the PSU board is still the same class II double insulated job used in the previous 6600 and 6800 versions it also won't requre a hard protective earth anyway. Providing a hard protective earth connection in the 6800 did more harm than good. One can only hope they've learn't their lesson by now. Has anyone managed to get hold of an FY6900 to check this out yet?

JBG

« Last Edit: June 10, 2019, 03:18:58 pm by Johnny B Good »
 

Offline GerryR

  • Regular Contributor
  • *
  • Posts: 216
  • Country: us
Hello, new here to this forum.  I had just purchased an FY6800-60M and ended up returning it.  The DC offset was over 35mV when set to 0.  There was a lot of jitter in frequencies above 20 MHz or so.  Amplitudes were way off into a 50 ohm load; there was considerable distortion in the output into a 10 k load.  Square waves started to look more and more like sine waves as frequencies got past 15 MHz.  Etc. Etc. Etc.   I haven't read all the posts in this thread yet, so I don't know if any of these problems have been experienced by others, but I am curious to know what others have found in actual use, i.e. tied to a real circuit and not just an o'scope.  Any input will be appreciated.
Still learning; good judgment comes from experience, which comes from bad judgment!!
 

Offline StillTrying

  • Super Contributor
  • ***
  • Posts: 2502
  • Country: dk
  • Country: Broken Britain
Seems to be new, slightly updated version (new case with back cooler):

00'010.000'000'000KHz

It looks like the 10kHz is very accurate, +/- 0.1ppb. :)
CML+  That took much longer than I thought it would.
 

Offline Cliff Matthews

  • Supporter
  • ****
  • Posts: 1810
  • Country: ca
    • General Repair and Support
You are assuming the big fat Earth pin is connected inside the box  :-DD  :horse:
Has anyone managed to get hold of an FY6900 to check this out yet?
AFAIK, they're still only pre-booking orders.
 

Offline bdunham7

  • Frequent Contributor
  • **
  • Posts: 389
  • Country: us
Hello, new here to this forum.  I had just purchased an FY6800-60M and ended up returning it.  The DC offset was over 35mV when set to 0.  There was a lot of jitter in frequencies above 20 MHz or so.  Amplitudes were way off into a 50 ohm load; there was considerable distortion in the output into a 10 k load.  Square waves started to look more and more like sine waves as frequencies got past 15 MHz.  Etc. Etc. Etc.   I haven't read all the posts in this thread yet, so I don't know if any of these problems have been experienced by others, but I am curious to know what others have found in actual use, i.e. tied to a real circuit and not just an o'scope.  Any input will be appreciated.

I think your issues are a combination of mediocre quality and unreasonable expectations on your part!  I don't know about the DC offset thing, my FY6600 is about 500uV offset so 35mV seems like a lot. The amplitude into 50 ohms will be lower than the front panel setting by about 1/2.  I can't address the HF jitter, mine is the 15MHz version.  The device has an output bandwidth of about 75MHz and at 250MSa/s, 100MHz would be the absolute ceiling anyway--therefore a 15MHz sine wave is only going to have the 3rd and 5th harmonics and that will look pretty rounded.  I realize that the settings allow you to select "square wave" up to 25MHz, but realistically 10MHz is about all these will put out that even resembles a square.  This is not a defect, simply a characteristic of a device with bandwidth limitations.

Yes, we've all had these issues and more.  However, I doubt you can find a better product at this price point.
 

Offline GerryR

  • Regular Contributor
  • *
  • Posts: 216
  • Country: us
bdunham7, thanks for your input.  I'm coming from a background where I have been using very high quality equipment, HP, Fluke Keithley, etc. so having to do a lot of fiddling to use an instrument is rather frustrating for me.  I don't think I was expecting too much after reading the specs of the instrument, but when you go back to the specs, you see that they left out some important info, like the output load for the specs given.  There is no "jitter" (edge, period) spec at all.  My fault for not looking a little deeper before purchasing.  I do agree that it is a lot of generator for the money, if you don't mind the fiddling, and from what I've seen, they would be better off just selling them as 20 MHz function generators with "some useful outputs to 60 MHz.
Still learning; good judgment comes from experience, which comes from bad judgment!!
 

Offline Johnny B Good

  • Frequent Contributor
  • **
  • Posts: 311
  • Country: gb
Thanks tried to get manual but it’s not uploaded yet
This link:
http://myosuploads3.banggood.com/products/20190606/20190606070659FY6900SeriesUsersManualV1.0.doc
worked perfectly for me, yesterday & today.

It's a MS Word docu, titled:

FY6900 Series Fully Numerical Control
Dual Channel Function/Arbitrary Waveform Generator
User’s Manual
Rev1.0     May,2019


 Thanks for posting the link. I've just downloaded and added it to my FY6600 folder for reference and having read through it I'm not particularly impressed. That increase to a 24Vpp only covers the frequency range DC to 5MHz. It would seem to be a "One Upmanship" exercise against the big players who are quite happy to regard the 20Vpp limit as the accepted "Industry Standard" (if you need more voltage amplitude, just add a linear amp).

 However, I did notice a downgrade of the 20Vpp limit over the range of 0 to 20MHz that applied with the FY6600 (and the FY6800 istr) to just 10Vpp from 10 to 20MHz. The FY6900 now adds the range 5 to 10MHz where the 24Vpp is reduced to 20Vpp before reducing the pp limit to 10V from 10 to 20MHz. It's quite obvious that this is their way to eliminate the gross distortion of their vast stock of THS3002i ICs they're still trying to use up.  >:( Since these limits are burnt into their proprietary firmware, this means you're going to see even less benefit out of an opamp upgrade to a pair of THS 3001/3095/3491s than was the case with the FY6600 and FY6800 models.  >:(

 I also noticed in their specifications a claim of less than 5 watts consumption which, imho, is an outright lie. I rather doubt they've managed to reduce the power consumption from the more typical 7 or 8 watts with the silicon upgrade required to achieve this reduction. Although a much improved smpsu board might gain some reduction, it's hard to see how they could trim off two watts worth on a 10W rated smpsu with the typical 80% efficiency rating for full load without raising the efficiency to 99%!  ::) This all seems extremely unlikely when you consider that their implementation of the power saving standby mode still consumes some 5 to 6 watts (a saving, afaicr, of only 1 watt or so at best).

 TBH, I think the FY6800 is the best OOTB product between the 6600 and this 6900 abomination. If they were to open source the firmware (unlikely in the extreme imo) or a keen enthusiast writes a replacement firmware (also unlikely but a more realistic scenario), this still leaves it lagging behind the performance of a fully modified FY6600/6800 even after it too has been fully modified.

 If I ever fancied getting my hands on another Chinese Cheepy, I'd choose the FY6800 since it's essentially an FY6600 with better front panel controls and the bulk of the earthed mains socket upgrade already completed (just needs some remedial work with a 10KR 'static drain' resistor and the damage to the ribbon cable making good).

 To my mind, after reading through the manual, this new FY6900 just looks like a downgraded version of its predecessors.

JBG
« Last Edit: June 10, 2019, 07:13:53 pm by Johnny B Good »
 
The following users thanked this post: Jacon


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf