amazing ARB pricing

Not just SMPS, many mains transformers and motors go into soft saturation near peaks. But in general I think it is more to do with the large number of appliances within a few tens of metres of you - the waveform on the HV grid pylons might be much purer?

piglet

Just browsing casually, in the 10-60 MHz range, going from $100ish to $350ish seems to get you from 8 bits to 12, 14, or 16 bits, and from 8 KPts to 1+ Mpts per waveform.

has a good selection of test gear so it's easy to compare features there (I'm a satisfied customer, YMMV), but there are more and more places to buy so price shop to your heart's content.

--
Regards, 
Carl Ijames

The analog scope will just show a solid rectangle of light when the sweep is too slow for the waveform. I think a digital scope could do that, with a bit of code, instead of aliasing. It could also intensity weight on duty cycle, like an analog scope does.

One quickly learns to recognize the aliasing and crank up the sweep rate.

--

John Larkin         Highland Technology, Inc 

lunatic fringe electronics

Lots of them do that now. It's a nice feature.

You can also just live in 'envelope' mode.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC / Hobbs ElectroOptics 
Optics, Electro-optics, Photonics, Analog Electronics 
Briarcliff Manor NY 10510 

http://electrooptical.net 
http://hobbs-eo.com

Lbs

on's

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for

it's a somewhat effective way to get a scope to see signals above its frequ ency limit, doing the enveloping externally.

NT

I prefer to just buy a faster scope. Why waste a nice excuse like that? ;)

I have scopes with bandwidths of 50 GHz (11801C), 20 GHz (11802), 3 GHz (TDS 694C), two at 1 GHz (TDS 784A), and a number of slower ones. Fast boat anchors are pretty cheap.

I would like one with serial decode eventually, but I rarely need that sort of thing.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC / Hobbs ElectroOptics 
Optics, Electro-optics, Photonics, Analog Electronics 
Briarcliff Manor NY 10510 

http://electrooptical.net 
http://hobbs-eo.com

Likely much less than $80. Even back in the early 90's we had Asian pricing and rest of world (ROW) pricing. I learned that very quickly when working in South Korea for the first time. Internet was in its infancy so they had wallpapered a whole hallway with daily updated computer printouts (remember the "tractor paper"?) and there was a constant pilgrimage to that wll by design engineers. It's amazing how low you can go if a transistor costs around one cent. They also did not have the hugely expensive placement cost penalty that many Western enterprises had to or sometimes still have to deal with.

What blew my mind was when in the mid-90's (!) someone showed the fully burdened cost of a simple fax machine, from scratch to packaged product with manual and all. That cost total was slightly under $7.

Profitably making and selling an ARB generator for around $100 is a piece of cake for Asians. Especially since the R&D costs are often, ahem, negligible.

--
Regards, Joerg 

http://www.analogconsultants.com/

(20, 30,

ency step

t just

compared to 20MHz. That's for the original unit from the factory. Some (may be most) of the eBay ones appear to be clones. I wonder if they cheaped out on the DAC.

100K pieces.

omers with friends with more convenient and easy to use high-performance, c ost-effective products.

the instrument sets the square wave output, press the F4 button to switch between the duty cycle and the lifting edge time setting, thus making the i nstrument more applicable! One of my sig gens' does square waves with adjustable edges, that can useful.

GH

the instrument button life is longer, the operating feel is more comfortabl e.

Speff! Good to see you back again! And making great sense, too. We need more of that here nowadays.

--
This message may be freely reproduced without limit or charge only via  
the Usenet protocol. Reproduction in whole or part through other  
protocols, whether for profit or not, is conditional upon a charge of  
GBP10.00 per reproduction. Publication in this manner via non-Usenet  
protocols constitutes acceptance of this condition.

I've mostly been using cheaper stuff, that doesn't have that feature. You turn it off and it forgets, and goes back to defaults.

Have you tried one of the new keysight 'scopes? I have yet to find something to complain about.. and mostly I'm just amazed. I was doing single screen captures bang... there's the event I'm looking for, now I need to see how it ends, I turn the time base knob.. and low and behold the rest of the signal is there!

George H.

It should be possible to download the scope data to a PC and run a freeware app to decode it.

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. :-)

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

And there are countries where you can buy CE stickers by the kilogram.

--

John Larkin         Highland Technology, Inc 

lunatic fringe electronics

you have to get them from somewhere

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

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

's

d p

h

hat

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 p aypal account to pay that way.

NT

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

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

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).

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

]

(

(

y

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