150w RF amp for 88-108MHz (band 2). The amp has 2 stages using a mosfet for the first stage (BLF244) which requires 0.5-1watt of RF input to get about 20watts to drive the final stage (the SD1407) which can push nearly 200Watts on this design!
This design is more or less broadband however I added 2 variable capacitors after each stage for optimum matching and power output. Make sure the trimmer and the capacitors after the final stage (SD1407) are a high voltage kind (at least 200v).
The power on this amp can be varied by adjusting the bias voltage (using the white pot) to the BLF244 mosfet. I added a zener diode onto the bias supply to protect the (expensive) transistor from too much bias voltage.
150W RF amplifier circuit schematic and PCB layout
Alex Hedberg
Hey MIke!
I am currently looking for a RF FM transmitter amplifier. These are the specifications I need:
Tech spec. needed:
Outputpower >2W
powersupply <12v
RDS support – (EON support)
Can I tune what packages I want?
Output impedence: 50 Ohm
Can it be interfaced through embedded systems or only things like windows?
I2C support (Optional) or similar
Can you help me with this or do you now someone who can? The amplifier is for a prototype and I will in the first round need 10 and later if we like it we might need 50-500 the next year.
Please contact me at alex@evamsystem.com
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Mike Hudson
Hey Joshua, thanks for stopping by. I agree the handwriting on the drawing is very poor. If there are any values you cannot read or see on the dwg then let me know and i’ll find it. I’ve known people be successful with that drawing only… good luck
Joshua Kaleb Scurlock
Do you have a parts list for this rf amp?