Gentlemen,
I've come across an RF transistor which seems to be available in 3 very different ecapsulations. I'll use these links from Ebay for simplicity and hope they're still up by the time anyone reads this. :-)
The first case appears to be based on the TO-220 dimensionos but appears to be all plastic:
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The second is what I would typically expect to see an RF transistor encased with:
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The final one is a conventional TO-220 with metal heat sink.
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The optimal casing is number 2, offering good thermal conductivity away from the device plus low parasitics.The one with the conventional TO-220 provides heat sinking adequate for a device of this power rating, but is not so good on the parasitics. Fortunately these are only used up to about 30Mhz so presumably get-away-with-able.
I don't know what to make of the all plastic encapsulation, which seems to have nothing to recommend it. Any comments? Datasheet here:
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