I agree with Tom, In general I never (fall for) cheap Chinese chips on eBay. But I have to say, UTSource seems to be an exception. I’ve gotten probably about 6 packages from them over the years. Not yet, V-regulators, but in every case the chips were 100% fine, and on the surface definitely appeared to be the genuine article. Some (video chips)were in their factory packages. It seem like there is a flood of 323k knockoff’s out there. I have actually been using 78H05’s These are 5V, 5A regulators. Yes I know overkill for our boards. But I happen to have an old stock of them here. Perhaps we should search around for these. I like Ian’s idea of checking out used parts stores. I have not done that in a while. I think I going to drop by a local one here , http://www.weirdstuff.com/ for anybody that lives in the bay Area. John From: n8vem...@googlegroups.com [mailto:n8vem...@googlegroups.com] On Behalf Of Tom Lafleur
Sent: Wednesday, June 4, 2014 4:53 AM
To: n8vem...@googlegroups.com
Subject: Re: [N8VEM-S100:3947] Re: Power distribution across an S100 Board and voltage issues with TO-3 Regulators.. I've been using UTSource for over 4 years, many order for older parts, never had an issue. But no matter where you get parts, there is always a chance of bad parts. ~~ _/) ~~~~ _/) ~~~~ _/) ~~~~ _/) ~~ On Tuesday, June 3, 2014 9:20:49 PM UTC-5, Tom Lafleur wrote: Looks like UTsource has large stock of LM323k and AK
There are three problems with utsource
1) Its basically ebay-ish so availability is random. If you have to get stuff like obsolete FDCs this way, then it has to be put up with it, but a simple 5V reg should not be this difficult to source.
2) I don't trust utsource, I ran the same search and got different results, and crucially, different prices, $8/each this morning. I assume we're both getting the same $4 shipping deal for a total of $12 per reg. I can buy a genuine factory sealed non-counterfeit non-pull made by TI from mouser for only $37 which is only 3 times as much, so I'd be tempted to use a known good reg rather than fry every chip on the board with a shorted reg or a remarked power transistor with a new silk screen. $12 is a lot of money for some dude to sandpaper off the silkscreen on a 2N3055, print LM323K on it, and ship it. I've heard the stories about the Jameco 323K and have gotten DOA 323K myself so I won't do business with distributors / resellers of those parts anymore. The greater marketplace itself for 323K's is broken and I'm done with it.
On the other hand, a LM323T is current production from multiple sources, distributors all over the world, it does the same thing, and I can add one to my existing Mouser order for a buck fifty. I usually buy ten-packs for a buck and a quarter each. So I can do the same thing for well under a thirtieth the cost if I'm willing to "compromise" and use a TO-220 shaped heatsink instead of a TO-3. So that's what I do. Sometimes takes a little hole drilling or creative use of mica insulators but it can always be done.
I do remember when 323K were like $2 but once my junk box emptied, and I found out it costs almost $40 a piece to refill the junk box, that it, I'm done with 323K, it was all 323T from then out no matter how ugly it made the board look.
3) UTsource refuses to list quantities other than ultra-vague less than 10, 10-100, and over 100. The problem is only some line items are over 100, and some of our PC board orders are getting to be 50-ish. So aside from the shadiness and extraordinary expense issues above, we're bordering on clearing the market, which is not going to amuse the pinball people and other historical users. They "need" antique TO-3 regs for restoration jobs and I feel bad poaching from them when we don't have to. No worries with the 323T, Mouser in the USA alone (and there's a zillion other mfgrs and other distributors) has over 5000 just of the STM part currently in stock and there's other distributors and other mfgrs so we're not going to disrupt anyones antique restoration project or whatever.
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