I ordered 20 of these:

https://www.newark.com/solid-state/1n270/rf-diode-pin-0-8pf-100v-do-7/dp/10P4366

...and received 20 of these:






Not sure what they're up to here, but these are not 1n270 or even germanium for that matter. They test to a forward voltage of 0.7, and they look like someone took some silicon diodes, painted them black, and stamped them with a fake part number.

Requested return on their website. After a few days they answered and requested a "video of the problem". Sure! I made them a nice little video comparing the looks and multimeter readings of a real 1n270 that I had in my collection vs. whatever this thing they sent me.

Took them a couple days again, they answered and said that had to forward the issue to their technical department. Man, are they really this hard up for the $30 they stole from me?!

Guess I'll give them a couple more days before I just dispute it on my card and forget it ever happened.

Lame.
 

your link gives me:
Access Denied (Error 403)

https://pinside.com/pinball/forum/topic/1n270-diodes-alternatives-gottlieb-system-one
https://www.lessmiths.com/crystal/dtest.shtml
https://www.diystompboxes.com/smfforum/index.php?topic=118007.0
https://synthcube.com/cart/index.php?route=product/product&product_id=7683
https://www.alldatasheet.com/htmldatasheet2/445438/NJSEMI/1N270/214/1/1N270.png

I don't know that Newark is being malicious. I think Newark sent you real, genuine 1N270s as supplied to them by the manufacturer, but also that the 1N270 is not what you really wanted. Sure, it says "germanium", on the datasheet, but it also says that Vf can be as big as 1.0V.

The 1N270 is a PIN diode, not a PN diode. It's specific to RF applications, and reacts differently to forward voltages than normal PN diodes. The fact that it happens to be made of germanium is incidental.

Newark probably thinks they played absolutely straight with you. I think that you misinterpreted the germanium in the data sheet for "has a forward voltage like a germanium PN diode" and it doesn't mean that because of the PIN nature. I would suggest asking if Newark will accept a return of the order.

Long rambling explanation follows.

Newark is a retail distributor. They buy large quantities of parts from manufacturers, store them, and sell them at a markup to low-quantity (that is, less than about 1000 - 10,000 at a time) buyers. It is decidedly not in their best interest to try to fool small-time buyers, as you note. Even more, it would take more work on their part to try to sell some faked/wrong parts to some people, not others. Keeping track of the foolery would require effort that isn't otherwise needed, and could destroy trust in them if it gets out.

One thing that Mouser, DigiKey, Newark and any other distributors do to earn their money is ensure the supply chain. After the flood of semiconductor fakes, the entire reputable parts industry, manufacturers, wholesalers, and distributors alike, got together and worked out ways to keep fakes out of the supply chain. So they work really hard at ensuring that they get the actual manufacturer's part. This effort has pretty much stopped fake parts being slipped into the bins at the distributors. I don't actually know that what you got was NOT a fake, but the odds are highly against it, just from an economics and reputation view.

I looked at the data sheet that Newark provides for the 1N270 from Solid State Inc., the manufacturer. The data sheet does say "germanium", but it also says "optimized for radio frequency response" and that the forward voltage is 1.0V max. I did some looking for more generic 1N270 diodes, and found that it is/was a PIN type: P-type-Intrinsic-N-type. The intrinsic silicon region between the P and N gives it a current-variable resistance in RF applications, and is the main reason to have a PIN diodes instead of a PN diode. Newark's data sheet does not say "PIN", but other data sheets for the 1N270 do. PIN diodes have different forward characteristics than PN diodes.

Quote from: Onion Ring Modulator on October 23, 2024, 08:27:18 AMI ordered 20 of these:

https://www.newark.com/solid-state/1n270/rf-diode-pin-0-8pf-100v-do-7/dp/10P4366

...and received 20 of these:






Not sure what they're up to here, but these are not 1n270 or even germanium for that matter. They test to a forward voltage of 0.7, and they look like someone took some silicon diodes, painted them black, and stamped them with a fake part number.

Requested return on their website. After a few days they answered and requested a "video of the problem". Sure! I made them a nice little video comparing the looks and multimeter readings of a real 1n270 that I had in my collection vs. whatever this thing they sent me.

Took them a couple days again, they answered and said that had to forward the issue to their technical department. Man, are they really this hard up for the $30 they stole from me?!

Guess I'll give them a couple more days before I just dispute it on my card and forget it ever happened.

Lame.
 

Quote from: Onion Ring Modulator on October 23, 2024, 08:27:18 AMNot sure what they're up to here, but these are not 1n270 or even germanium for that matter. They test to a forward voltage of 0.7, and they look like someone took some silicon diodes, painted them black, and stamped them with a fake part number.

What's missing is the test current you are using.  Without that it can't be said the diodes you have are silicon.  Perhaps measure the diode voltage with 100uA though it.  If you get 0.5V to 0.6V then it's probably silicon.

Test at 1mA to compare with other ge diodes.

At higher test currents you may very well see 0.7V drop on a ge diode.

You can see how the diode drop depends on the test current.  Taken from Duck's link to the old thread,

QuoteFernando

1N270  0.236V@1mA, 0.34V@6mA FAKE? - sold as BKC but suspicious reading. One thick black line (see below) - STEEP CURVE
1N270  0.265-275V@1mA, 0.58-0.62V@6mA - (ST) two black lines. - SMOOTH CURVE
1N270  0.30-32V@1mA, 0.79-1V@6mA  -  (Unknown brand) two black lines. - VERY SMOOTH CURVE
...
I was very surprised of such a different readings from the 3 different types of 1N270 diodes (I tested many specimens of each type)
The type sold as "BKC" on the bay (showing a picture of a BKC bobbin and even having "BKC 1N270" printed on their body) match Ivan's plot for "1N270-Modern" (at least up to 6mA). They have one thick black line. FAKE ?
The other two 1N270 types had different Vf but with a more credible curve, both close to Ivan's plot for "1N270-NOS".

Good point Rob.

Another thing that is missing is that to the manufacturer, the actual things they stuff into shipping containers are not the "part". The part is the DATASHEET, and anything that fits inside the minimums and maximums on the datasheet is one of them, and can be shipped and supported by warranty.

That's why I put in that stuff about the data sheet saying 1.0V max. To the manufacturer, if they are made of germanium, and the forward drop is less than 1V at 200ma, how the forward voltage gets to that point is irrelevant. The disconnect is that "germanium" is not equal to "has the same V-I characteristic at lower currents as a normal germanium PN diode".

The fact that Vf is not 0.2 to 0.3V at lower currents is not relevant to the manufacturer, or to a certain extent, Newark. From their point of view they (very, very probably) shipped the parts meeting the datasheet promises. As you correctly point out Rob, they even might be similar to ordinary 1N34-ish germaniums at low current. Maybe.  But they're intended for something else, and that intrinsic region may do funny things to low-current voltages.

Quote from: R.G. on October 23, 2024, 12:03:00 PMAnother thing that is missing is that to the manufacturer, the actual things they stuff into shipping containers are not the "part". The part is the DATASHEET, and anything that fits inside the minimums and maximums on the datasheet is one of them, and can be shipped and supported by warranty.

Agreed.  Technically (legally) the part only has to comply with what is on the datasheet.   Many datasheets, especially early parts, had very wide tolerance and many unspecified parameters.  Very sparse datasheets with ranges you could pass a bus through.   The real parts however had much tighter specs and the unspecified parameters tended to sit within a reasonably tight window.   Well, at least from the major suppliers.  We might even see some consistent differences between suppliers.   Some examples of such parameters are: diode drops, and transistor VBE, diode and transistor capacitances.

The thing is you could trust that these unspecified parameters were going to be in some ball-park.   It's more of a gentleman's agreement than a legal agreement.  (Sometimes one manufacturer would specify an extra parameter and you could build-up a picture of some of the "unspecified" parameters by looking at datasheets across different manufacturers and different eras.)

As cheaper parts and alternative manufacturers started to infiltrate the market, say as early as the 80's, the parts have a tendency to deviate from those unspecified parameters more and more.   While they meet the specs in the datasheets they don't comply with the gentleman's agreement.   One example that comes to mind are the capacitances of BD139 transistors.  The original Philips parts had quite low junction capacitances but some of the cheaper knock-offs had more than 5 times capacitance.  The capacitances aren't specified so it passes the datasheet.

Thanks for all the feedback. I think the most important thing I missed on that listing page is the line "Image is for illustrative purposes only. Please refer to product description." - the image is the regular transparent glass 1n270 that I am used to. I'm sure my fellow ADHD travelers will relate...

What a pity that we are separated by a huge distance, and I cannot simply hand over to you a whole handful of old real germanium diodes, knowing that they will not just lie around idle, but will come in handy.
Huge distance + complete lack of experience in sending international parcels.

If you need a place for them to go, happy to pay shipping!   

Quote from: sinthmart on October 24, 2024, 10:15:58 AMWhat a pity that we are separated by a huge distance and I can't just give you a whole handful of old, real germanium diodes, knowing that they will not just lie around, but will also serve for something.

CheapSuitG - International parcels from Russia seem like an extremely complicated procedure to me, but maybe I'm wrong and I should go to my post office and find out first-hand how it works. And how expensive it is.
What country do you live in? You can't send parcels from Russia to some countries. And in general, my country is behaving in a particularly vile manner right now(( Rolling back into the barbaric past.

I am in the USA, probably not worth you time to check. Appreciate it though! 

Quote from: CheapSuitG on October 25, 2024, 12:24:37 PMНо я ценю это!

Yes, very far. And it seems unlikely and illogical.
But I went to the post office and asked. The main difficulty for me will not even be the amount (which seems acceptable to me, as an exception), but filling out the parcel registration (I don't like all these things)). But let's not give up on this option yet.
I only ask you to share these diodes with those who are really interested)).
I can even do this for the sake of my respect for your wonderful, and my beloved Tom Waits))

Quote from: sinthmart on October 29, 2024, 08:02:46 AMI can even do this for the sake of my respect for your wonderful, and my beloved Tom Waits))

I send you a virtual beer!! Tom Waits is one of my musical favorites. I even once got to see him live in a bar in downtown Austin Texas when he was starting out.

If you have some, happy to share with people in the US!

Quote from: sinthmart on October 29, 2024, 08:02:46 AM

Quote from: CheapSuitG on October 25, 2024, 12:24:37 PMНо я ценю это!

Yes, very far. And it seems unlikely and illogical.
But I went to the post office and asked. The main difficulty for me will not even be the amount (which seems acceptable to me, as an exception), but filling out the parcel registration (I don't like all these things)). But let's not give up on this option yet.
I only ask you to share these diodes with those who are really interested)).
I can even do this for the sake of my respect for your wonderful, and my beloved Tom Waits))