High Frequency power amplifier.

Audioguru again

Joined Oct 21, 2019
The very old amplifier circuit was designed by students in South Asia.
It produces interference to other communications that makes it illegal.


Joined Jan 23, 2018
This circuit was not "designed", but rather drawn based on what looks good. It might sort of function on ham radio frequencies, but not very well. It appears to be a single frequency application, and it is not suitable for any other applications. In addition, it is a "class C"amplifier and will deliver a rather distorted signal at any frequency except the one it is tuned to.


Joined Nov 6, 2012
Why do You need "DC to 3Mhz" ???
How much Power do You need ??

You're not likely to get DC from any RF-Amplifier,
DC and RF just don't mix well.

For high-Power-Broadcasting, a single, huge, Vacuum-Tube may be the simplest solution.

Just purchase a Linear-Booster-Amplifier for CB-Radio.
All the inevitable Bugs have already been worked-out.
It will go all the way to ~30Mhz comfortably, and without any drama.

Solid-State-RF-Amplifiers work by special "Magical-Spells",
it's almost impossible to make one operate the way it's supposed to on paper.
Fudge-Factors seem to apply to every single part,
including what time of the Day it was manufactured.

Thread Starter

david miles

Joined Jan 20, 2013
Thanks for all your answers- really good.
As I need something tunable, I will now obviously drop the design I posted.
I will buy something if I have to, but I would prefer to make something myself if I can.
So, can anyone point me to a circuit design that could be tunable from say 1Khz to 3Mhz with a reasonably clean output signal? It doesn't need to be super powerful.


Audioguru again

Joined Oct 21, 2019
LEDs use DC current. The output of an RF amplifier is AC current.
You can connect LEDs back-to-back plus a current-limiting resistor then some LEDs light during the positive voltage swing and the other LEDs light during the negative voltage swing.
Why use audio, ultrasound and Radio Frequencies to light LEDs??


Joined Oct 7, 2019
I would like to have a circuit that can light up a 10watt led module, or a bunch of normal white leds.
Please tell us what 10W LEDs you want to use. What power you have. We are looking at a LED driver.
Also, I don't know of a reason to turn a LED on/off at 3mhz. Maybe a laser LED.


Joined Aug 21, 2008
Bandwidth in that range is easy to get. The key questions are what kind of power you need and what the source and load impedance are.


Joined Feb 24, 2006
Bandwidth in that range is easy to get. The key questions are what kind of power you need and what the source and load impedance are.
Funny you should mention that. One recent poster claimed, without offering any evidence, that they were negligible. What he meant was that he did not know how to measure, compute, or estimate them, so they were going to be ignored.