UHF (70cm) PA
BV wrote:
P.S. It's a linear amp i want to build
73 de OZ1BV, Brian
A bit of advice:
The Motorola data book suggests that these devices are designed for Class C
service, and their design guide gives a circuit without DC bias. The Vbe max
is only 4 Volts, which gives a useful hint!
Your DC bias circuit needs to /very/ accurately track temperature to prevent
thermal runaway - the design of the bias circuit /will/ /not/ be trivial.
The gain of the circuit will be disappointing - you'll be lucky to get close
to 10 dB - so the drive requirement will be surprisingly high.
If I was designing a UHF PA, I'd choose FETs these days!
Bob
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