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take a look at this circuit

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rishi_azzuris

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hi there,

can somebody tell me what is this port1, port2, port3, port4. i'm confuse which port is the power supply, is it port 1 or port 2.. or both are power supply ports. there was a phrase in this document stating
"The amplifier is keyed by applying 28 V to R1, this turns on the transistor. The collector can be left with 28 V also during receiving."

i don't understand this phrase above. can somebody explain to me. i also need to know which is the rfin and rfout ports. pls state to me which ports is it, is it port 3 or 4. i've put the circuit below with the ports on the diagram itself. i'm sure you guys out there can help me find the ports.pls help
 

E-design

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He uses the voltage drop across the diode to bias the transistor on via the choke. He uses a 28V supply on the collector and a key switch from the 28V supply to turn the transistor on and off. During receive there will be no RF drive, the 28V bias will be off. Leaving the 28V on the collector will make no difference as the transistor is turned off and has no RF drive. The bias diode is usually in close thermal contact with the transistor to enable the bias to compensate (lower the bias voltage) as the device heats up.

RF input is at C1, RF out at C5 and 28V supply on Dr3
 

rishi_azzuris

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i've completed this circuit, now i'm testing it. will i be able to measure the output power if i don't give a rfin signal. if yes, how do i do it?
 

E-design

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The article says you need a 1-10W RF signal into this amp. You need to find one. Maybe someone you know has a VHF ham TX.
 

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