odd looking 2N5088 7429

[Will.mendil]

Hi,

Although I have been checking this forum for a whilst, this is my first post. I just bought some 2N5088 online, and received the parcel today, and strangely enough, the transistors I got look weird. I am only starting to fill up my stock on parts and i have never seen any of those. Has anyone bought similar transistors? are they the same (just a different manufacturer) basically, what's up with them?




I have not tested them yet, and I therefore do not have any standard 2N5088 to compare them with. So if anyone has any insight on this matter, it will be very welcomed.

Cheers

[theehman]

pics?

[Will.mendil]

woops, apparently the links did not work, my bad.

here they are:

[theehman]

photos are marked private

[Will.mendil]

a bit big, but voila

[theehman]

Never seen any like that.  Wouldn't surprise me, though.

[Pojo]

Where did you get them?

[Will.mendil]

I don't know if I should say. _ebay....

[smallbearelec]

Consider yourself lucky. I have never seen 2N5088s in a "dot" package like that, though some of the other TO-106 and TO-109 that I have do get up into the 300-400 bucket that's typical for the device. So they may well be "real". What do the gains measure?

[Pojo]

Do you have a multimeter with an hfe function? All 2n5088's I've seen typically have hfe that fall within the 300-600 range, just your typical high gain silicon NPNs. I would imagine they're fine, I see no reason anyone would counterfeit or relabel transistors as common and cheap as these. But the package makes me curious of the story behind them...if it's just an early version or something.

[Will.mendil]

Unfortunately, I do not have any function to characterise transistors on my multi metre. Has any of you got a idea on how to measure the gain of this transistor with the basic functions of a victor 86C.

They do look cool, and i actually wonder if the legs are not gold plated, or maybe it's just brass. Is it a good bargain or a rip off (1,89 dollar rip off ^^) (for 20 of them)

[Will.mendil]

Maybe someone recognises the logo.

[Will.mendil]

Apparently you were right. It seems to be a TO106 package



I am going to look online to see if there's anything special about this packaging. Though maybe someone has an idea.

[digi2t]

Are there any more for sale?

Looks like the Teledyne logo.

[PRR]

Sure looks like quite old Teledyne. Mil-quality. I suspect nobody has that molding machine running today. So the molding is probably NOS. The stamping is easily forged. But I don't think Teledyne is much sought after. The part number could also be forged, but why forge a good number on an odd package from a forgotten brand?

1974 date-code is reasonable and fairly sweet. By this time TI had set a high standard in epoxy Silicon for long enough that competitors like Teledyne had caught-up.

[PRR]

> anything special about this packaging

No.

Except that's a lot of thick gold on the leads.

At the time, it was considered less rugged than metal types, better-looking than TI's one-shot epoxy package. In fact the epoxy packages have generally been more reliable than metal, not that you'd know in a stompbox.

The early forms of this package were two parts. A white cup to hold the header, then the black epoxy to seal it. This may also have side-stepped TI's patents on one-shot packaging. Really the "hard" way to do it, though made sense when you were only set up to make a million instead of a billion.

[Will.mendil]

Well I've ordered some, hopefully, normal 2n5088 and will do a comparison test on a tone bender or maybe you can call for a better 2n5088 pedal with standard parts to test these transistors.


PRR > They look super cool though!

[digi2t]

Don't mean to harp, but are there any more of these for sale? If so, could you shoot me a link?

[duck_arse]

doesn't really matter the performance, you got yourself a load of good mojo there, though. very nice.

[Will.mendil]

Sorry, but the link was an auction an ebay, apparently from a private seller, I cannot find any new offers, and the description specifically stated that they were meant to be TO 95. So I don't even now if they are going to sell any more of these.