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help with high frequency amplifiers

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wakoko79

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I'm building a high frequency amplifier for fm transmission (~96MHz). Can anybody give links/ pointers regarding this?

We are to transmit power to a 50ohm antenna with 10dBm power.

I just don't know what to do. Please help.
 
It has to be discretes because IC's can't go that high. You might buy one of the Radio Shack inline TV-FM amps. I took one apart once and it is pretty simple.

It's been a long time since I worked on this stuff, but I know there are transistors specifically designed for RF amp applications.
 
You won't go far wrong with a 2N3866 transistor in the output stage. Others to consider are BFR90/BFR91/BFR92/BFR96/BFR96S if they are available where you are. 10dBm is quite a low power so you won't probably need a tuned circuit although if you can, it will help with effiency.
Just be aware that 96MHz is in the commercial FM band of practically every country in the world, so you may/well be illegally interfering with a licensed band.
 
You won't go far wrong with a 2N3866 transistor in the output stage. Others to consider are BFR90/BFR91/BFR92/BFR96/BFR96S if they are available where you are. 10dBm is quite a low power so you won't probably need a tuned circuit although if you can, it will help with effiency.
Just be aware that 96MHz is in the commercial FM band of practically every country in the world, so you may/well be illegally interfering with a licensed band.

I guess that's why the power was set to only 10dBm. Can you give tutorials/ link about the actual circuit? I would be happy even if the output stage is just a class A and driver stage are CE amps. I just want it to work for checking. We're currently discussing Y-parameters in class so it really doesn't help much in designing actual circuits.
 
There are several FM transmitter ICs available, as I discovered with a quick Google search. They don't say what the output power is.
I'm not endorsing these as the optimal learning experience - I'm just responding to a previous post.
 
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Thats a good link roff
the IC's have datasheets assoc with them that the OP can click on and view the specs :)

Dave
 
I guess that's why the power was set to only 10dBm. Can you give tutorials/ link about the actual circuit? I would be happy even if the output stage is just a class A and driver stage are CE amps. I just want it to work for checking. We're currently discussing Y-parameters in class so it really doesn't help much in designing actual circuits.

I think you underestimate the power. A local signal of 10dBm at 96MHz will knock out FM radio receivers for several hundred metres with even a small aerial.
 
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