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I usually buy electronics components at an online surplus store and they usually throw in the box some more goodies to pack what you order.

I bought a multi section plastic container and it was filled with all sort of components, and this one in particular intrigues me. Here is a photo:

Mystery components

They seem to be transistors, maybe their odd shape is because they are RF or something...

Some "old school" guy that has used them?

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  • \$\begingroup\$ The answer below from @jippie is likely to be correct, but are there any markings on these? \$\endgroup\$ – David Mar 14 '14 at 11:50
  • \$\begingroup\$ They're very colorful. Most of that type wot I've seen have been black epoxy. Are they perhaps ex-Soviet parts? \$\endgroup\$ – Spehro Pefhany Mar 14 '14 at 13:53
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Transistors in a TO-50 package commonly used in RF applications. The leads can be soldered flat onto the PCB, reducing lead inductance. Can be either some type or FET or BJT.

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    \$\begingroup\$ I concur and have used devices like this in RF designs. You can still buy them from regular sources. \$\endgroup\$ – Andy aka Mar 14 '14 at 10:52
  • \$\begingroup\$ that was my suspect. There is no marking on them anyway... \$\endgroup\$ – Vladimir Cravero Mar 14 '14 at 13:41
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While they may be what Andy and jippie say, they also MAY be "MMIC"s

Wikipedia - MMIC aka Monolithic microwave integrated circuit.

These often have a 4 lead package with 2 opposite pins being ground, but this is not essential. And a transistor may also have 4 leads with two being ground. The image below is from the above Wikipedia page.

enter image description here

However, to rather meld the answers given - a MMIC "IC" MAY be as simple as a single transistor with internal biasing resistors. Or a pair of transistors. Or much more.

The diagram below is a Mini-Circuits ERA series MMIC amplifier.
Diagram from Mini-Circuits AN-60-10 BIASING MMIC AMPLIFIERS - e.g., ERA SERIES

enter image description here

Which ends up in circuit diagrams looking like this:

enter image description here


This one actually uses all 4 pins for different functions - so yours is not one of these :

enter image description here

BUT, some of these could be - Table 15 from this useful page

enter image description here

But, ALL of these with 4 leads are transistors intended for LNA use (table 1).

enter image description here

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