Phil Hobbs wrote:> > I would like one with serial decode eventually, but I rarely need that > sort of thing.It should be possible to download the scope data to a PC and run a freeware app to decode it.
amazing ARB pricing
Started by ●October 25, 2018
Reply by ●October 28, 20182018-10-28
Reply by ●October 28, 20182018-10-28
On Sun, 28 Oct 2018 08:43:17 +0000, Tom Gardner wrote:> On 27/10/18 23:07, Johnny B Good wrote: >> It turns out the purity of the UK's national grid 50Hz sine wave >> supply >> is somewhat lacking even when compared to that of a cheap 2.8KVA >> generator [1]. For reference, it's more accurately best described as >> having a 'down sloping' flat topped appearance (with respect to >> absolute amplitude - it's an 'up-slope' on the negative peaks). I make >> this reference for the benefit of those armed only with a cheap digital >> 'scope[2] that simply shows a flat topping effect without any hint of a >> slope on the mains waveform versus the more pure looking sine wave from >> a cheap 1KW Parkside inverter generator (PGI 1200 B2). > > The "clipped sine wave" appearance surprised me, when I looked at it for > the first time since the 70s. > > I believe it is because there has been a change in the loads on the > grid. Nowadays there are a large number of devices with SMPSs. Many > presume a more-or-less constant input voltage throughout the mains > cycle, so they rectify the and smooth the mains, "topping up" the charge > in the capacitor only at the peak voltages. Hence significantly more > current is drawn at the peaks than at other parts of the cycle.That was my very first thought when I proved that the 50Hz 'Cal' waveform was indeed a true reflection of the mains supply. This issue of "Low PF loads by virtue of the narrow conduction angle" of the full wave bridge rectifiers with capacitor smoothing in the HT modules of SMPSUs in desktop PCs and more and more domestic kit which started to appear in the mid 80s, became recognised by the regulatory bodies who enacted regulations to force the manufacturers to address this problem by including PFC circuitry in all new designs above a minimum power rating (quite possibly the old 20W limit imposed on non PFC magnetically ballasted fluorescent lamps - remember the Philips SL18 CFL, anyone?). It's been quite a few years since I last recorded a mains supply waveform for closer examination so the sloped flat topping effect might not be quite so pronounced today. I've still got my mains voltage sampling wallwart transformer to hand so that will be one of the first things I'll be looking at with whatever DSO I finally decide to plump for. :-)> > As for inverters (i.e. not petrol-driven generators), I would be wary > about applying a "modified sine wave" output to valuable equipment. The > PSU might be unfazed by such rectangular input, but in cheap equipment, > who knows.I use an APC BackUPS500 to protect my NAS box from outages effecting the "Protected Supply" provided by the SmartUPS2000 in my basement. This is a "quasi-sine wave" (modified square wave - a circa 330 Vpk square wave with a 30% or so dead dead time between polarity reversals to approximate a 240vrms supply for IT kit possessed of PSUs that couldn't give a toss about "Sine-wave Purity"(tm). The SmartUPS feeding the 'Protected Supply' is a line interactive type meaning it passes the mains supply straight through, monitoring not only for outright outages/brownouts and dangerous surges and spikes, but also for the more modest sags and swells which it will boost or buck by switching taps on its (rather weighty) mains transformers to condition the supply voltage without resorting to running its sine wave inverter and burning up precious battery charge/discharge cycle life. The main charm of quasi sine-wave types of UPS is not only their low price but also their lower running cost in terms of their 'maintainance consumption'; in this case just under 3 watts versus the 32 to 35 watts of the SmartUPS2000 and the 20W exactly of the smaller SmartUPS700 (700VA/450W) long since retired due to having the worst maintainance consumption to protected capacity ratio of all of my UPSes. However, such good maintainance consumption to protected power level ratios aren't guaranteed to be as good as that 25 year old BackUPS500 so beware of this the next time you go shopping for a cheap 'n' cheerful UPS and ask to check the full manufacturer's specification, making it clear if needs be (the manufacturers tend to be silent on this point) that if it consumes more than 1% of its maximum wattage output capacity rating in maintainance consumption (what it takes after fully recharging its battery pack), you reserve the right to return it as "Not Fit For Purpose". As long as you restrict the use of such quasi sine-wave inverter based UPSes to kit that you know for sure to be using an smpsu such as desktop PCs etc, there's not really going to be a problem. However, if you're powering a cheap LED lamp via such a supply to provide a modicum of emergency lighting to avoid having to scrabble around in the pitch black by the glow of only an indicator LED or two, you may find yourself in the dark in short order anyway as the square wave pulses passed by the dropper capacitor to the LED string either kills the inrush limiter resistor (assuming the bean counters hadn't decided it was an unnecessary luxury item that could be replaced with a wire link) or else the LED string itself. If you're going to use a cheap clip on lamp holder to provide emergency lighting during an outage, your safest bet would be to pick one that'll accept a 15W pygmy lamp (either that or keep a battery powered LED lantern to hand for such emergencies). -- Johnny B Good
Reply by ●October 28, 20182018-10-28
On 28 Oct 2018 13:24:22 GMT, Rob <nomail@example.com> wrote:>Tom Gardner <spamjunk@blueyonder.co.uk> wrote: >> I believe it is because there has been a change in the loads >> on the grid. Nowadays there are a large number of devices >> with SMPSs. Many presume a more-or-less constant input voltage >> throughout the mains cycle, so they rectify the and smooth the >> mains, "topping up" the charge in the capacitor only at the >> peak voltages. Hence significantly more current is drawn at >> the peaks than at other parts of the cycle. > >More modern SMPSs should fix that by having PFC (Power Factor Correction). > >It basically is an extra switching boost-converter in front of the main >capacitor operating from unsmoothed rectified mains, it converts the >half-sinewave voltage to a constant voltage to charge the capacitor. >(the working point of the converter is changing all the time in the >rhythm of the mains voltage) > >Of course there still exists a lot of equipment without this, now >manadatory, feature. And it is not required for lowpower devices, >which become more and more prevalent.And there are countries where you can buy CE stickers by the kilogram. -- John Larkin Highland Technology, Inc lunatic fringe electronics
Reply by ●October 28, 20182018-10-28
mandag den 29. oktober 2018 kl. 00.38.04 UTC+1 skrev John Larkin:> On 28 Oct 2018 13:24:22 GMT, Rob <nomail@example.com> wrote: > > >Tom Gardner <spamjunk@blueyonder.co.uk> wrote: > >> I believe it is because there has been a change in the loads > >> on the grid. Nowadays there are a large number of devices > >> with SMPSs. Many presume a more-or-less constant input voltage > >> throughout the mains cycle, so they rectify the and smooth the > >> mains, "topping up" the charge in the capacitor only at the > >> peak voltages. Hence significantly more current is drawn at > >> the peaks than at other parts of the cycle. > > > >More modern SMPSs should fix that by having PFC (Power Factor Correction). > > > >It basically is an extra switching boost-converter in front of the main > >capacitor operating from unsmoothed rectified mains, it converts the > >half-sinewave voltage to a constant voltage to charge the capacitor. > >(the working point of the converter is changing all the time in the > >rhythm of the mains voltage) > > > >Of course there still exists a lot of equipment without this, now > >manadatory, feature. And it is not required for lowpower devices, > >which become more and more prevalent. > > And there are countries where you can buy CE stickers by the kilogram.you have to get them from somewhere
Reply by ●October 28, 20182018-10-28
On Sat, 27 Oct 2018 13:53:34 -0700, jjhudak4 wrote:> On Friday, October 26, 2018 at 11:32:42 PM UTC-4, Johnny B Good wrote: >> On Fri, 26 Oct 2018 13:27:07 -0700, Klaus Kragelund wrote: >> >> > A 200MHz scope for 379 USD: >> > >> > >> I've been considering replacing my ancient 1950s CRT dual beam 70Lbs >> 'scope with something more up to date recently and this Siglent >> Technologies SDS1202X-E 'scope looked like it might be a good value >> proposition (a snip at a mere £363.05 for UK customers via Amazon's >> 'Fulfilment' delivery) so have checked out some reviews[1] which seem >> to confirm this view. >> >> However, this is a subject of very recent interest so I haven't yet >> researched this in any great depth as yet so I was wondering if you had >> any advice on this 'scope or possibly better alternatives (100MHz B/W >> dual trace at a minimum) that you could offer to aid me in my search >> for a reasonably specced and priced unit? >> >> [1] Amazon customer reviews here: >> >> <https://www.amazon.co.uk/Siglent-Technologies-SDS1202X- >> Oscilloscope-Channels/dp/B06XZML6RD/ref=sr_1_1? >> ie=UTF8&qid=1540608976&sr=8-1&keywords=sds1202x-e> >> >> TinyURL <https://tinyurl.com/ydgpong6> >> >> (click the customer reviews link near the top of the page) >> >> >> The Defpom's Repair Channel review videos here: >> >> <https://youtu.be/64kxGDOg7es?t=19> Part 1 >> <https://youtu.be/laK1v2Zas4o?t=12> Part 2 >> >> -- >> Johnny B Good > > To each their own. When I wanted something a bit more portable than my > Tek 7903 I got a used tek for ~$250 USD, spent some time cleaning it up > and calibrating. Good as new. Not quite as glitzy but solid and > serviceable. > > Some tek scopes have Tek specific ICs and modules that are very hard to > find, but on the whole, very serviceable, if that be your inclination. > Post your interest on the tek NG and you will receive some very useful > info. >Thanks for that suggestion regarding the existence of a Tek News Group. That's well worth adding to my NG list (at least we're *not* dealing with some forum hosted on a shitty website). :-) In the meantime, I've just tracked down the UK agent for Siglent (labtronix.co.uk) who are selling the SDS1202X-E for a mere £365 with free delivery (by virtue of it being over £70). Also, they mention that they hold new stock with serial numbers which include the all important "BB" characters signifying that they're not the earlier versions that had been plagued by a probe compensation issue. Since they *are* a UK company based in Loughborough, Leicestershire, I've bookmarked their website as a potential supplier should I finally settle on this 'scope for lack of a better alternative. However, this may be one of those companies that only accept Paypal transactions... Just checked out their Ts & Cs and this is the case. I did set up a Paypal account several years ago but haven't used it and have steadfastly refused to acknowledge the endless pleas to change my account settings that I was receiving in my inbox every few months which may or may not have been phishing attacks - ignoring them seemed the safest policy since if genuine, the worst that could happen would be Paypal suspending or deleting my account, either of which would have suited me. I'm not overly keen to reactivate the old account or create a new one so it looks like I won't be buying from a company that doesn't support the more mainstream methods of payment such as Visa and the like. Possibly I'm being a little over-cautious in my steering clear of Paypal involvement - should I be? The few Paypal transactions I had made had all been successful, it was the emails about changes in their Ts & Cs and the requests to log into my account to change my settings (and no doubt agree to the new Ts & Cs) which rather put me off using Paypal for any more online transactions. However, I might change my mind about this given compelling enough reasons. -- Johnny B Good
Reply by ●October 29, 20182018-10-29
On Monday, 29 October 2018 02:40:29 UTC, Johnny B Good wrote:> On Sat, 27 Oct 2018 13:53:34 -0700, jjhudak4 wrote: > > > On Friday, October 26, 2018 at 11:32:42 PM UTC-4, Johnny B Good wrote: > >> On Fri, 26 Oct 2018 13:27:07 -0700, Klaus Kragelund wrote: > >> > >> > A 200MHz scope for 379 USD: > >> > > >> > > >> I've been considering replacing my ancient 1950s CRT dual beam 70Lbs > >> 'scope with something more up to date recently and this Siglent > >> Technologies SDS1202X-E 'scope looked like it might be a good value > >> proposition (a snip at a mere £363.05 for UK customers via Amazon's > >> 'Fulfilment' delivery) so have checked out some reviews[1] which seem > >> to confirm this view. > >> > >> However, this is a subject of very recent interest so I haven't yet > >> researched this in any great depth as yet so I was wondering if you had > >> any advice on this 'scope or possibly better alternatives (100MHz B/W > >> dual trace at a minimum) that you could offer to aid me in my search > >> for a reasonably specced and priced unit? > >> > >> [1] Amazon customer reviews here: > >> > >> <https://www.amazon.co.uk/Siglent-Technologies-SDS1202X- > >> Oscilloscope-Channels/dp/B06XZML6RD/ref=sr_1_1? > >> ie=UTF8&qid=1540608976&sr=8-1&keywords=sds1202x-e> > >> > >> TinyURL <https://tinyurl.com/ydgpong6> > >> > >> (click the customer reviews link near the top of the page) > >> > >> > >> The Defpom's Repair Channel review videos here: > >> > >> <https://youtu.be/64kxGDOg7es?t=19> Part 1 > >> <https://youtu.be/laK1v2Zas4o?t=12> Part 2 > >> > >> -- > >> Johnny B Good > > > > To each their own. When I wanted something a bit more portable than my > > Tek 7903 I got a used tek for ~$250 USD, spent some time cleaning it up > > and calibrating. Good as new. Not quite as glitzy but solid and > > serviceable. > > > > Some tek scopes have Tek specific ICs and modules that are very hard to > > find, but on the whole, very serviceable, if that be your inclination. > > Post your interest on the tek NG and you will receive some very useful > > info. > > > Thanks for that suggestion regarding the existence of a Tek News Group. > That's well worth adding to my NG list (at least we're *not* dealing with > some forum hosted on a shitty website). :-) > > In the meantime, I've just tracked down the UK agent for Siglent > (labtronix.co.uk) who are selling the SDS1202X-E for a mere £365 with > free delivery (by virtue of it being over £70). Also, they mention that > they hold new stock with serial numbers which include the all important > "BB" characters signifying that they're not the earlier versions that had > been plagued by a probe compensation issue. > > Since they *are* a UK company based in Loughborough, Leicestershire, > I've bookmarked their website as a potential supplier should I finally > settle on this 'scope for lack of a better alternative. However, this may > be one of those companies that only accept Paypal transactions... Just > checked out their Ts & Cs and this is the case. > > I did set up a Paypal account several years ago but haven't used it and > have steadfastly refused to acknowledge the endless pleas to change my > account settings that I was receiving in my inbox every few months which > may or may not have been phishing attacks - ignoring them seemed the > safest policy since if genuine, the worst that could happen would be > Paypal suspending or deleting my account, either of which would have > suited me. > > I'm not overly keen to reactivate the old account or create a new one so > it looks like I won't be buying from a company that doesn't support the > more mainstream methods of payment such as Visa and the like. Possibly > I'm being a little over-cautious in my steering clear of Paypal > involvement - should I be? The few Paypal transactions I had made had all > been successful, it was the emails about changes in their Ts & Cs and the > requests to log into my account to change my settings (and no doubt agree > to the new Ts & Cs) which rather put me off using Paypal for any more > online transactions. However, I might change my mind about this given > compelling enough reasons.several companies say they only take paypal, when really they accept debit/credit cards, they just use paypal to process them. You don't even need a paypal account to pay that way. NT
Reply by ●October 29, 20182018-10-29
On Sun, 28 Oct 2018 22:52:58 -0700, tabbypurr wrote:> On Monday, 29 October 2018 02:40:29 UTC, Johnny B Good wrote:====snip====>> >> I'm not overly keen to reactivate the old account or create a new one >> so >> it looks like I won't be buying from a company that doesn't support the >> more mainstream methods of payment such as Visa and the like. Possibly >> I'm being a little over-cautious in my steering clear of Paypal >> involvement - should I be? The few Paypal transactions I had made had >> all been successful, it was the emails about changes in their Ts & Cs >> and the requests to log into my account to change my settings (and no >> doubt agree to the new Ts & Cs) which rather put me off using Paypal >> for any more online transactions. However, I might change my mind about >> this given compelling enough reasons. > > several companies say they only take paypal, when really they accept > debit/credit cards, they just use paypal to process them. You don't even > need a paypal account to pay that way. >Thanks for that hint, NT. I'll try making an order to see what options are *actually* available at the payment details stage of the transaction. BTW, has anyone dealt with this company before? I haven't seen any comments about Labtronix as a supplier. Just wondering whether anyone here has any horror/good experience stories to relate in their dealings with them. -- Johnny B Good
Reply by ●November 7, 20182018-11-07
On Fri, 26 Oct 2018 08:21:39 -0700, speff wrote:> On Friday, 26 October 2018 06:40:37 UTC-4, Clifford Heath wrote: >> On 26/10/18 7:42 pm, speff wrote: >> > On Thursday, 25 October 2018 17:27:24 UTC-4, John Larkin wrote: >> >> https://www.amazon.com/Adoner-Precision-Arbitrary-819214bits-Modulation/dp/B07BF7Y7TJ/ref=sr_1_3? ie=UTF8&qid=1540502597&sr=8-3&keywords=fy6600&dpID=41vbYI% 252B7YiL&preST=_SX342_QL70_&dpSrc=srch>> >> >> >> Other places have this box for $99. >> > >> > $99 would be a very good price, from what I can see, better than >> > China list- looks like a more normal price would be about $150-$200 >> > in the US for the 60MHz version. The lower frequency versions are >> > significantly cheaper. >> > >> > It appears to use an Altera Cyclone IV FPGA driving 14-bit DAC. >> > 320x240 color TFT. This is NOT your hobbyist DDS chip. >> >> The prevalence of cloning in this kind of device is usually because >> someone published the designs. >> >> It's often an advanced hobbyist. I have a couple of gadgets like this; >> if you search hard enough you can find the original blog postings >> showing where the design was developed. There are plenty of hobbyists >> advanced enough to have developed this design. >> >> I haven't searched, but mere hardware copying wouldn't result in the >> plethora of clones; the original software has to be published >> somewhere. Otherwise the cloners would have to write it again >> (differently) to accommodate any design changes, and that's too much >> like hard work; they'd need to understand how what they were cloning >> works. > > Googled it and there's a huge thread at EEVBLOG on this product. > > https://www.eevblog.com/forum/testgear/feeltech-fy6600-60mhz-2-ch-vco-function-arbitrary-waveform-signal-generator/>Yeah, thanks (I think). I've just spent the last couple of hours reading that thread and am only on page 8 (after having a quick peek at the last 10 pages to see how it petered out)! My interest is motivated by my purchasing a "fy6600-60m" in the small hours of this morning for £75.66 from an Ebay trader offering free[1] delivery from a UK warehouse (delivery ETA 10th to 12th of this month). This buying decision was prompted by several days of watching countless Youtube reviews and teardown videos ad nauseum (I was resorting to not only (briefly) watching repeats but also looking at Russian and German language reviews). "You certainly have to kiss an awful lot of frogs to find your prince.". In this case, I mostly found warty toads amongst the 'frogs' and the closest I came to finding a 'prince' was still a frog. :-( The business with PSU mains frequency leakage from the smpsu used is simply the price you pay to reduce the more obnoxious HF switching spikes from polluting the DC rails - it's a fekin' compromise that none of the moaning nincompoops seemed to properly understand. Also, another stand out "moan of ignorance" was in regard of the DC offset range interaction with the Pk2Pk voltage swing limits. Then there was the even more staggering ignorance that you need to terminate a 50 ohm co-ax feed, fed from a 50 ohm signal source with... guess what? A FIFTY OHM RESISTIVE LOAD!!! Gah! Even a radio ham fell into this trap. :-( After finally satiating myself of all this low grade video evidence on Youtube, I finally managed to conclude that this would be a suitably cheaper alternative to the 360 quid Siglent SDG1032X Signal Generator I'd been eyeing up on Labtronix.co.uk to go with my recently purchased Siglent SDS1202X-E dual channel 200MHz 1Gsa/s DSO (also from Labtronix). At a mere £75.66 postage free delivery within the week, I can easily forgive its "shortcomings". For the money, it's excellent value, "warts 'n' all". That thread in EEVblog seems to offer ways and means by which to sandpaper down the more objectionable warts - I have yet to finish reading it. Still, it's something to help pass the time whilst I wait to take delivery of my 'new toy'. :-) The PSU leakage issue can be readily sorted - there's ample room to even fit an inefficient analogue PSU should one so wish but a much better solution, imo, is to use a decent smpsu that uses a transformer which incorporates a shield between the HT and LT windings to avoid having to resort to the bodge of a 5nF Y cap to ground the HF hash to half mains voltage via another pair of Y caps which measure introduces the possibility of damaging ESD sensitive electronic kit as a result of this compromise. Anyway, the EEVblog thread you linked to looks well worth reading, especially now that I've paid my money and have an actual "fy6600-60m" about to wing its way to me. :-) [1] Unfortunately, the courier in this case is Royal Mail and their tracking web page is still claiming "Tracking information is not available for this service" which could mean that "goodlucksell" haven't handed it over or, just as likely, Royal Mail haven't updated their tracking system (or their tracking system is so slow, it's shit). -- Johnny B Good
Reply by ●November 7, 20182018-11-07
On Thursday, November 8, 2018 at 12:04:50 AM UTC+1, Johnny B Good wrote:> On Fri, 26 Oct 2018 08:21:39 -0700, speff wrote: > > > On Friday, 26 October 2018 06:40:37 UTC-4, Clifford Heath wrote: > >> On 26/10/18 7:42 pm, speff wrote: > >> > On Thursday, 25 October 2018 17:27:24 UTC-4, John Larkin wrote: > >> >> https://www.amazon.com/Adoner-Precision-Arbitrary-819214bits- > Modulation/dp/B07BF7Y7TJ/ref=sr_1_3? > ie=UTF8&qid=1540502597&sr=8-3&keywords=fy6600&dpID=41vbYI% > 252B7YiL&preST=_SX342_QL70_&dpSrc=srch > >> >> > >> >> Other places have this box for $99. > >> > > >> > $99 would be a very good price, from what I can see, better than > >> > China list- looks like a more normal price would be about $150-$200 > >> > in the US for the 60MHz version. The lower frequency versions are > >> > significantly cheaper. > >> > > >> > It appears to use an Altera Cyclone IV FPGA driving 14-bit DAC. > >> > 320x240 color TFT. This is NOT your hobbyist DDS chip. > >> > >> The prevalence of cloning in this kind of device is usually because > >> someone published the designs. > >> > >> It's often an advanced hobbyist. I have a couple of gadgets like this; > >> if you search hard enough you can find the original blog postings > >> showing where the design was developed. There are plenty of hobbyists > >> advanced enough to have developed this design. > >> > >> I haven't searched, but mere hardware copying wouldn't result in the > >> plethora of clones; the original software has to be published > >> somewhere. Otherwise the cloners would have to write it again > >> (differently) to accommodate any design changes, and that's too much > >> like hard work; they'd need to understand how what they were cloning > >> works. > > > > Googled it and there's a huge thread at EEVBLOG on this product. > > > > https://www.eevblog.com/forum/testgear/feeltech-fy6600-60mhz-2-ch-vco- > function-arbitrary-waveform-signal-generator/ > > > > Yeah, thanks (I think). I've just spent the last couple of hours reading > that thread and am only on page 8 (after having a quick peek at the last > 10 pages to see how it petered out)! > > My interest is motivated by my purchasing a "fy6600-60m" in the small > hours of this morning for £75.66 from an Ebay trader offering free[1] > delivery from a UK warehouse (delivery ETA 10th to 12th of this month). > > This buying decision was prompted by several days of watching countless > Youtube reviews and teardown videos ad nauseum (I was resorting to not > only (briefly) watching repeats but also looking at Russian and German > language reviews). "You certainly have to kiss an awful lot of frogs to > find your prince.". In this case, I mostly found warty toads amongst the > 'frogs' and the closest I came to finding a 'prince' was still a frog. :-( > > The business with PSU mains frequency leakage from the smpsu used is > simply the price you pay to reduce the more obnoxious HF switching spikes > from polluting the DC rails - it's a fekin' compromise that none of the > moaning nincompoops seemed to properly understand. > > Also, another stand out "moan of ignorance" was in regard of the DC > offset range interaction with the Pk2Pk voltage swing limits. Then there > was the even more staggering ignorance that you need to terminate a 50 > ohm co-ax feed, fed from a 50 ohm signal source with... guess what? A > FIFTY OHM RESISTIVE LOAD!!! Gah! Even a radio ham fell into this trap. :-( > > After finally satiating myself of all this low grade video evidence on > Youtube, I finally managed to conclude that this would be a suitably > cheaper alternative to the 360 quid Siglent SDG1032X Signal Generator I'd > been eyeing up on Labtronix.co.uk to go with my recently purchased > Siglent SDS1202X-E dual channel 200MHz 1Gsa/s DSO (also from Labtronix). > > At a mere £75.66 postage free delivery within the week, I can easily > forgive its "shortcomings". For the money, it's excellent value, "warts > 'n' all". That thread in EEVblog seems to offer ways and means by which > to sandpaper down the more objectionable warts - I have yet to finish > reading it. Still, it's something to help pass the time whilst I wait to > take delivery of my 'new toy'. :-) > > The PSU leakage issue can be readily sorted - there's ample room to even > fit an inefficient analogue PSU should one so wish but a much better > solution, imo, is to use a decent smpsu that uses a transformer which > incorporates a shield between the HT and LT windings to avoid having to > resort to the bodge of a 5nF Y cap to ground the HF hash to half mains > voltage via another pair of Y caps which measure introduces the > possibility of damaging ESD sensitive electronic kit as a result of this > compromise. > > Anyway, the EEVblog thread you linked to looks well worth reading, > especially now that I've paid my money and have an actual "fy6600-60m" > about to wing its way to me. :-) > > [1] Unfortunately, the courier in this case is Royal Mail and their > tracking web page is still claiming "Tracking information is not > available for this service" which could mean that "goodlucksell" haven't > handed it over or, just as likely, Royal Mail haven't updated their > tracking system (or their tracking system is so slow, it's shit). >Thanks for the hint I just bought one also. I have a HP33120 Arb, but it is single channel, and I need dual channel to do PWM signals for halfbridge drivers etc Cheers Klaus
Reply by ●November 7, 20182018-11-07
On Mon, 29 Oct 2018 15:23:30 +0000, Johnny B Good wrote:> On Sun, 28 Oct 2018 22:52:58 -0700, tabbypurr wrote: > >> On Monday, 29 October 2018 02:40:29 UTC, Johnny B Good wrote: > > ====snip==== > > >>> I'm not overly keen to reactivate the old account or create a new one >>> so >>> it looks like I won't be buying from a company that doesn't support >>> the more mainstream methods of payment such as Visa and the like. >>> Possibly I'm being a little over-cautious in my steering clear of >>> Paypal involvement - should I be? The few Paypal transactions I had >>> made had all been successful, it was the emails about changes in their >>> Ts & Cs and the requests to log into my account to change my settings >>> (and no doubt agree to the new Ts & Cs) which rather put me off using >>> Paypal for any more online transactions. However, I might change my >>> mind about this given compelling enough reasons. >> >> several companies say they only take paypal, when really they accept >> debit/credit cards, they just use paypal to process them. You don't >> even need a paypal account to pay that way. >> > Thanks for that hint, NT. I'll try making an order to see what options > are *actually* available at the payment details stage of the > transaction. > > BTW, has anyone dealt with this company before? I haven't seen any > comments about Labtronix as a supplier. Just wondering whether anyone > here has any horror/good experience stories to relate in their dealings > with them.Apologies for the tardy follow up but I decided to try ordering the 'scope from Labtronics the following day to see whether I could pay without having to revive or create a paypal account and discovered the Guest Paypal option which I chose to complete my order. The 'scope arrived two days later and I've been a little preoccupied in the six days since then gaining familiarity with 'My New Best Friend' (that and dithering over whether to order a Siglent SDG1032X for 360 quid or go for the much cheaper FY6600-60M at a more disposable £75.66 instead). As you can probably imagine, such choices don't magically resolve themselves these days without spending hours and hours checking out Youtube review and tear down videos ad-nauseum until you can't find any more new ones, no matter how hard you look, created by people with a proper understanding of things like 'mains tingle voltage' from every commodity SMPSU ever used without benefit of safety earth connection and the importance of terminating a 50 ohm BNC cable with a 50 ohm resistive terminator and so on and so forth. When I have to read between the lines (more a case of looking past the misunderstood misgivings which seem to pointlessly pad out a 10 or 15 minute video into an hour long treatise on how to modify this or that aspect of the kit in question), that can be quite a few evenings (even afternoons - really, most of the day but with natural breaks and lunch, tea and supper breaks plus the odd household chore and food shopping trip) worth of my time before I'm finally convinced I made the best cost/ performance trade off choice I possibly could (in the circumstances... I reassure myself - I finally plumped for the FY6600-60M). Said FY6600-60M is promised to reach me any day between Saturday and Monday - Sunday seems unlikely, it's via Royal Mail so even Saturday seems optimistic. After spotting that the only difference in spec between the 30, 50 and 60 MHz versions lay in the upper sine wave frequency limit (all else being identical), it did occur to me that the differences might simply have been a matter of a firmware upgrade and possibly a couple of capacitors or some such so I tried searching for a 60MHz hack for the slightly cheaper 30MHz model. Surprisingly, in view of the various mods referenced in the EEVblog thread, none were forthcoming. However, with typically less than a tenner price difference between the 30 and the 60MHz models, I wasn't too put out. An 8 to 10 quid price premium on the 60MHz model over the 30MHz one seemed a fair enough price point but that hadn't stopped me from looking for a possibly even cheaper option. Now that I'm satisfied I hadn't overlooked an opportunity to pay even less for a 60MHz sig gen, I feel a little happier over splurging that little extra on the 60MHz model. At least it's ready to go without the faff of hacking a 30MHz unit, leaving me to address just the other perceived shortcomings so roundly discussed in the EEVblog here: <https://www.eevblog.com/forum/testgear/feeltech-fy6600-60mhz-2-ch-vco- function-arbitrary-waveform-signal-generator/> Apologies if Pan has line wrapped the url. You can try the Tinyurl below if it has. <https://tinyurl.com/y9kydgwx> I've got as far as the eighth page in that 69 page thread. I did have a look at the last few pages to get a hint of just how long it had lasted. However, "cutting to the chase" in a long thread like this isn't a sensible idea when there seems to be some worthwhile discussion about improving the product. I just might learn some useful things about my next 'new toy'. :-) -- Johnny B Good
