25-08-2019, 12:59 PM
Certainly a partial explanation. You'd need three things for it to work for a seller:
1) Getting a load of LM317T for nearly nothing. The prevalence of NOS out of production parts from China suggests large left over inventories from when a product ended. That's totally believable.
2) Ability to remark a part very easily and cheaply with almost no labour and invisibly.
3) A very large number of people buying LM338T that only need LM317T. The real LM338T is cheap anyway.
You've sort of explained (3) though considering how cheap "real" LM338T are there must be a lot of cat 3 people and (1) and (2) must staggeringly apply. Most of these sellers have a huge inventory of parts that do what is claimed. The usual kind of "fake" is actually for expensive military/Aerospace/automotive parts and the supplied parts work. What are they faking? Two aspects. One is that the part may be actually ex-equipment and the other is that the part is probably really only tested to commercial for domestic production and possibly also in a cheaper package (material or radiation levels).
It's possible that the suppliers to the sellers are doing the fraud, I suppose.
I've had problems years ago with RS, so the companies changed to Farnell. Long ago Radiospares never returned parts to the maker. I worked in a Capacitor factory in early 1970s and all the just out of spec parts were sent to them if the production targets were not met. At the end of the 1970s in another company we had sealed clear bubble packs of RS parts pined to the notice board: Pre-blown fuses, screws with no thread etc. No doubt RS has improved QA as selling to production & R&D has replaced sales to Service Depts of Radio & TV shops.
I found that Maplin in its last years was dreadful. I was getting cheaper parts at better quality from Asia.
Professional users etc are better buying from Mouser, Farnell, RS etc. But many hobbyists can't afford them, especially outside UK and with the shipping charges etc. So we buy ex-USSR surplus from Baltic States and Eastern Europe and cheap parts from Asia.
1) Getting a load of LM317T for nearly nothing. The prevalence of NOS out of production parts from China suggests large left over inventories from when a product ended. That's totally believable.
2) Ability to remark a part very easily and cheaply with almost no labour and invisibly.
3) A very large number of people buying LM338T that only need LM317T. The real LM338T is cheap anyway.
You've sort of explained (3) though considering how cheap "real" LM338T are there must be a lot of cat 3 people and (1) and (2) must staggeringly apply. Most of these sellers have a huge inventory of parts that do what is claimed. The usual kind of "fake" is actually for expensive military/Aerospace/automotive parts and the supplied parts work. What are they faking? Two aspects. One is that the part may be actually ex-equipment and the other is that the part is probably really only tested to commercial for domestic production and possibly also in a cheaper package (material or radiation levels).
It's possible that the suppliers to the sellers are doing the fraud, I suppose.
I've had problems years ago with RS, so the companies changed to Farnell. Long ago Radiospares never returned parts to the maker. I worked in a Capacitor factory in early 1970s and all the just out of spec parts were sent to them if the production targets were not met. At the end of the 1970s in another company we had sealed clear bubble packs of RS parts pined to the notice board: Pre-blown fuses, screws with no thread etc. No doubt RS has improved QA as selling to production & R&D has replaced sales to Service Depts of Radio & TV shops.
I found that Maplin in its last years was dreadful. I was getting cheaper parts at better quality from Asia.
Professional users etc are better buying from Mouser, Farnell, RS etc. But many hobbyists can't afford them, especially outside UK and with the shipping charges etc. So we buy ex-USSR surplus from Baltic States and Eastern Europe and cheap parts from Asia.
