Can i put a mosfet instead of BJT in a RF amplifier circuit ?(RD06HVF1 instead of 2SC1971)

Thread Starter

Maz2858

Joined Jan 27, 2021
5
I am making a RF amplifier circuit that needs 2SC1971 npn transistor but i don't have it anymore so i bought RD06HVF1 mosfet from an uk seller from ebay so i want to know if i can just replace the 2sc1971 with a RD06HVF1 in my RF power amplifier circuit
Thx
 

dl324

Joined Mar 30, 2015
12,442
Welcome to AAC!

MOSFETs aren't drop-in replacements for BJTs. If you post the schematic, we can determine which parameters would be important for a substitute BJT.
 

Thread Starter

Maz2858

Joined Jan 27, 2021
5
Hi ! Here is the schematic for my RF amp (there are 4 stages actually)
I want to use RD06HVF1 mosfet instead of 2SC1971 bjt
Thanks

RF AMP.png
 

bertus

Joined Apr 5, 2008
21,148
Hello,

There will be almost nothing seen on the output.
C22 of 0.1 μF will basicaly short the RF signal.

For the mosfet, you will have to create a bias voltage on the gate.
On page 5 of the datasheet in post #2 there is an example circuit for 175 MHz.

Bertus
 

Thread Starter

Maz2858

Joined Jan 27, 2021
5
Sorry, i typed the wrong value in the capacitor, the 0.1u capacitor at the ouptut is actually 75pF
Thanks for the info
 
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