What the heck is this ceramic disc with fins?

gage

May 8, 2013
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I've tried the google. i've tried numbers and combinations of numbers. i don't see anything written on the other side of them. they're roughly between the size of a dime and a quarter.

I have a handful of these things and i have absolutely no idea what they are. can anyone tell me if it's a capacitor, resistor, plutonium container, whale caltrop, or suchlike?

thanks a bunch!
 

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gage

May 8, 2013
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They appear to be old school transistors...

**EDIT**

Confirmed, RF amplification transistors...

Coke is it, as they say! Thanks so much, now i can google the heck out of them.

(on a related note, it appears that the whales don't have anything to worry about...)

Really appreciate your help. I guess the new rule is, if it has a multiple of three contacts, maybe it's a transistor.

thanks again,

gage
 

davenn

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Sep 5, 2009
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just for your info
commonly the connections are .....

attachment.php


The 4 emitter pins are connected internally as shown by the black lines

All the emitter pins go to the groundplane of the circuit board
The larger of the 2 centre pins is usually the Collector, larger because its carrying more RF current

Dave
 

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duke37

Jan 9, 2011
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WARNING
Some RF transistors use beryllia as an insulator. Do not damage it, how would you dispose of it?
 

shrtrnd

Jan 15, 2010
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I don't know if this device has beryllium in it, but for trivia:
The dust from beryllium is supposed to be toxic when inhaled.
We use a lot of devices with beryllium in them, and yeah, we have to pay a hazardous
waste disposal place to get rid of them when they go bad.
But just using devices with them is supposedly alright. We're just prohibited from
sanding, lapping, or allowing any of it to turn to dust which can be inhaled.
 

gage

May 8, 2013
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Thanks, all (and especially to davenn for the general case). Seems odd to have four emitters, but that's probably because i have no idea what the heck i'm talking about.

Does look like i have some playtime for the weekend though. Still have more googling to do to find a datasheet, then it's time to break out the multimeter, arduino, etc, and go to town.

Also, thanks, duke, for the Beryllium warning. Since i have about 20 of these things, it's good to know that crushing and snorting them is a bad idea :) (Seriously, though, thanks - I'd rather not expose myself, the kids, etc, to Be).
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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Jan 21, 2010
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Seems odd to have four emitters

Just 1 emitter, but 4 connections to it.

Not a designer of RF stuff, but it speaks to me of a desire to have the lowest impedance connection to the ground plane as possible. And I'm thinking Class C, but that's just a series of educated guesses.
 
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