Hi, here is a circuit which protects the output transistor from accidental SWR. If SWR increased, the supply to the output transistor (via Q2) will decreased, wow!
- I am little confused on C12 (polarized). I think on original circuit, there is only "1" so I guessed 1uF. Or should I have to show you a original old circuit?
- And I think I can use almost any transistor as Q2 which has Ic= 2A or 3A (like BD135?). And any general PNP and NPN as Q3, Q4, Q5 like BC557 (PNP) and BC547 (NPN). Any huge mistake?
-And....it's designed to almost 25 or 30 watt Tx. The rectified voltage is through 10k potentiometer so I thought it can work even at 1 watt Tx or even at 100watt Tx, isn't it?