Rigol oscilloscope prices have sky-rocketed!

"geoff"

or the Rigol example

or the ebay user agreement

- you sheep shagging kiwi FUCKWIT !!

.... Phil

Yeah when we had surplus stores here I got many big transformers that way. They all (electronics surplus stores) disappeared years ago unfortunately.

MrT.

It shouldn't be a problem until a local official seller that can't possibly sell them for the same price complains. There are countless companies like (presumably) Rigol that have diferent wholesale pricing in different countries, so an official dealer in say Australia can't even buy it for less than what someone in China sells it for at a profit. Or to hold on to their dealership they aren't allowed to sell it under a certain price. With the advent of ebay and online trading, the world is a global marketplace, so these sorts of traditional regional pricing models make it a big fat mess. You can bet your bottom dollar the ebay sellers in China are (or were) not dumping the scopes at a loss, they made a very tidy profit.

I have since heard that another Rigol seller also had their auctions banned for "dumping". So this appears to be the reason for removal of the hundreds of Rigol's that were for sale on Ebay. So it's likely that one (probably official Rigol) seller, that may not even sell on Ebay, spoiled all the fun by complaining.

Dave.

And that affects eBay how?

MrT.

sage

nit

wave

It will certainly make it very noisy

I don't know where "here" is for you, but in the SF Bay Area, so much manufacturing has left the area that the surplus stores are struggling to get surplus stuff. Throw ebay into the equation, and there is even less stuff available in stores. But isolation transformers are more of a lab item than a production item, so they may still be in your area locally, but probably stashed in some garage.

Topaz transformers show up from time to time at electronics flea markets. In the days when small company owned a Vax, the Topaz was your isolation transformer.

Have a nice day. Oh wait, somebody as screwed up as you never has nice days.

You really make the rest of the Aussies look bad.

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log.com

Dumping is selling beneath the cost of manufacturing, so only the manufacturer can dump. A vendor can buy out the merchandise from a store that goes out of business and sell those items for less than the manufacturing cost. In the states, the FTC would have to declare a dumping situation. [I haven't had to deal with the FTC in a long time, but it was an amazingly accessible organization considering you were dealing with the government.

Like I've said, I need to see the documents on this alleged dumping. I just don't see Ebay taking sides in any kind of dispute like this. Rather, I see Rigol deciding not to sell stock to certain vendors that they don't like. An individual company can set up any distribution channel is desires (well maybe excluding automobiles). A prime example is Apple, that reduces it's vendors to keep the price of their good high.

You can make an isolation transformer that will handle a kilowatt from two junked microwave oven transformers. Just remove the HV windings and the magnetic shunt, leaving the primary windings. Connect them together with two coils wound on each core with a few turns of No 12 insulated building wire. Calculate the number of turns to not exceed 20A at the intended maximum load.

ay.

ly.

This sounds very bodgy to me.

Getting 2 identical transformers, and putting the 2 primary windings on one core would be a better idea This would involve taking them (the E and I parts) apart and putting them back together - not easy for the inexperienced.

Whether in practice it would work well is another matter.

There almost certainly aren't any, it's an internal ebay decision. The seller probably just got an email informing them their listings have been removed because of a breach of some rule, and that's it, end of story. Some monkey at Ebay has spoken.

Ebay are judge, jury and executioner, and they are famous for showing it. Indeed, they have to be shown to take complaints of legal matters seriously, and they err on the side of caution every time. If they get any complaint with the wiff of a legal basis, they'll just pull the listing(s). Their site, their rules, they don't muck around, and the "victim" (sellers in this case) usually doesn't get any recourse.

Maybe, but there are many other ways to obtain them, esp in China, so that doesn't explain the lack of no more cheap Rigol scopes on Ebay. The only facts are that Ebay have removed the cheap Rigol listings for what they are calling "dumping". You can still buy the unit at the old cheap prices from various other online dealers, drop-shippers, and Chinese sources, here is but one example:

Dave.

Yep, had a Topaz myself once, but I've never seen one going cheap in Australia! Not to say it can't happen, but you'd have to be very lucky, not something the OP can necessarily go and buy at a reasonable price just because he wants it. And not something you'd want to carry in your car either, to use with an inverter supply!

MrT.

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Freight for a Topaz down under would be significant. Topaz has made some units that are small, well small for a Topaz. Maybe 12x8x8 inches.

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log.com

I didn't want the scope. [I'm the one that suggested getting a used Tek versus Chinese mystery gear.] I'm just very doubtful of the story. Ebay has as much to lose from dissing a seller as to dissing an manufacturer. In fact, more to lose from dissing the seller since the manufacturer isn't sell their product on ebay.

Basically, the story doesn't pass the smell test. Now if Rigol cut out the sleazy dealers, that would also explain the scope not being on ebay, right? It is far easier for Rigol to not give the jerk gear to sell rather than try to get ebay to prevent the sale.

Doctor, it hurts when I do this. Well, stop doing that!

I have heard from two people who have contacted previous Rigol ebay sellers directly, and both have said their listings were pulled for the same "dumping" reason. So there is no reason to doubt the story.

Ebay already make so much money the commisions on these scopes are nothing to them. It is more important to them that they be seen to be acting on complaints. It's been happening for many years now, nothing new here at all.

Wrong. As I said, there are plenty of places to buy this scope wholesale cheaply in China, so I imagine it would be hard for Rigol to cut out these small time ebay sellers directly. There were so many cut price Rigol sellers on ebay you didn't know were to look, everyone simply jumped on the Rigol popularity bandwagon, flipping it for a profit to us westerners from whomever they bought it from in China. There were zero reported cases of any dodgy sellers. All that are left now are a couple of the expensive sellers.

Nope, much easier for someone (maybe Rigol directly, we don't know) to simply complain to Ebay and let them use their famous overzealous legal paranoia to block all cheap sellers. Doing it the other way around would be like pushing brown stuff up a hill with a pointy stick.

Dave.

Would it work if I just connect HV windings together? So as to avoid any rewounding job.

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If you have to do it - try using a pair of 240 - 110v / 48v / 24v units back to back or other matching voltage low voltage surplus transformers.

I did this 25 odd years back using 2 surplus (free) 240v to 24v @15a units back to back, and it worked fine for many years. It wont be as efficient as a single purpose designed transformer, and will be heavier and run hotter.

Remembering that there will be 2 lots of losses, and that normal transformers aren't designed to be used "backwards", you will NOT get the full rated VA out of this arrangement, it will cost more in electricity use.

I wouldn't even contemplate that idea of putting microwave HT windings back to back - it would be an absolutely totally and instantly LETHAL device if anything went wrong, not just an irritating "ZAP". Please, Please Please do NOT muck about with these things. these voltages (remember that unlike TV EHT supplies these oven transformers have plenty of current behind them) can even punch through damaged or underrated insulated tool handles and to your hand, delivering a lethal shock !

If there was a breakdown to the output winding, which could possibly happen with old parts - specially ones from faulty microwaves pulled from rubbish dumps, or that had mouse / insect infestations - I would hate to think what could possibly happen to anyone or anything connected on the 240v isolated "secondary" side.

If you didnt join the 2 HT windings together in a proper way, and insulate properly the connection point could even arc, starting a fire.

Either physically remove the HT winding first if you are going to muck around with it, or better still, just do yourself a favour and chuck the microwave oven transformer (and the modification idea) in the rubbish bin before someone gets killed.

not

Ouch ! That is one hell of a transformer :)