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Old February 4th 07, 05:41 PM posted to rec.radio.amateur.homebrew
mister35mm mister35mm is offline
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First recorded activity by RadioBanter: Apr 2006
Posts: 3
Default Two QRP questions, one easy, the other, tricky...

Ok then.... I give up.

I had checked out the maximum frequency on all these old bipolar power
trannies, and basically, I've stuck them on ebay.

I seem to have quite a few BD139 power transistors. They are not as
'meaty' looking as they are medium power, plastic cased and are not
small signal types.

Looking at the data sheet he- http://www.ortodoxism.ro/
datasheets2/6/0rwiehk82adehe25p4gkxjros2yy.pdf

It say these transistors are good up to 190MHz, so does this mean I
can use one instead of a 2n2222 (I have lots of these BD139's and if
they'll work, I'd like to try)

Would I have to change any of the component values of the Michigan
Mighty Mite ( http://cs.okanagan.bc.ca/ve7ouc/eng/kc6wdk-
mirror/transmitter.html ) component values to use a BD139? Say 1/2 or
1 watt resistors?

Stephen
G7VFY