(Part 2) How to Design, Build, and Test an RF Linear Amplifier (LTSpice)

This multi part video focuses on the critical design aspects of an RF Push-Pull amplifier. The example shown uses an IRF510 MOSFET transistor to explain impedance matching, biasing, amplifier classification, circuit stability, feedback, tuning, power output, harmonic distortion, and other important design characteristics. It also introduces LTSpice, a FREE simulation tool. From this video, the viewer will gain an in-depth understanding of how to design, build, and test an RF power amplifier. Please visit my web site for the RF amplifiers and other products I offer. rflinear-amplifiers.com

[@enriquevarela8616]

Fantastic explanation is a topic that no one explains on CZcams and if it does, it does so in a very complex way that we radio amateurs cannot understand
Thank you very much, greetings from Spain

[@rfmanchannel6915]

I'm happy you found this helpful! RF Man

[@pctoollaptop9212]

with these videos sir history is written a greek radio amateur is behind this message is fully understood this work you are doing keep up the good work

[@markadams8676]

Great video , looking forward to the rest of the series ..

[@rfmanchannel6915]

Thanks for your feedback!! RF Man

[@johnjames378]

Very good, looking forward to the next video.

[@LACA999]

Today's Elec. engineering students totally lucky than us, we were not 30 years ago and you are growing this help with gorgeous explanation. 73's

[@LousyPainter]

Very well explained! Thanks.

[@joselobo8731]

Thank you. After a month trying to change a Band pass filter i saw in another video, where the autor showed an LCSpice simulation of his filter but.... without sucess, in 30 mins of watching your video i made it. Once again thank you for sharing your knowledge. 73's

[@pctoollaptop9212]

Με αυτά τα βίντεο κύριε γράφεται η ιστορία ένας έλληνας ράδιο ερασιτέχνης είναι πίσω από αυτό το μήνυμα είναι πλήρης κατανοητό αυτό το έργο που κάνετε συνεχίστε να είστε καλά

[@alfonsea3bfl869]

Good job RF man.

[@rfmanchannel6915]

Thanks for you comment!! RF Man

[@tawfiqulalam8928]

Very nice demonstration, thanks a lot.

[@reallybadaim118]

Thank you

[@zahedalsawadi7084]

Excellent explanation ... Thank you.

[@pilobond]

I've been using LT Spice for a while, but never new you can do this. Amazing and thank you. VA3GPJ

[@CircuitShepherd]

The inductance is proportional to the square of the number of turns.

[@rfmanchannel6915]

Yes. Also, the impedance ratio equals the number of turns squared or the square root of the impedance ratio equals the number of turns. Regards

[@davidmcneill3964]

@@rfmanchannel6915 Since the inductance is proportional to the turns ratio squared, the 20uH:10uH inductance ratio is equal to a turns ratio of root(2). Then, since the impedance ratio is equal to the turns ratio squared, root(2) squared is 2, thus transforming 100 ohms to 50 ohms, or 25 ohms to 50 ohms. It's intuitive when the ratio is 2, but when you require some oddball number for an impedance ratio, it's easier to do the math.

[@bob_mosavo]

Thanks 😁

[@YO6TJJ]

At min. 28:51 you meant a 1:2 ratio isn'it (instead of 2:1 what you said) Because it is 10uH PRI and 20uH SEC? I watched the video careffully and learned a lot from it. Thank you so much! I am doing live in LTSpice all your demo now.

[@emailuser3869]

RF Man can't thank you enough for taking this on! 73 W6MGV

[@RodneyStevens]

This is a great series of videos! Would you be willing to share the LTSpice file with all the components?

[@hb9hal]

👍

[@letitrotfuckit]

Thank you for the video. for some reason I cannot get LT spice to give me the correct impedance values, for a 1 to 1 match it gives me the resistance in fOhms which are apparently very small. How do I couple the two inductors? man the tool is not easy to use at all, it is a challenge, if only EasyEda could measure impedance(I do not know how to tell it to).

[@rfmanchannel6915]

You need to use the 'K' directive. Here's an example for L1 and L2 which are 2 separate inductor. (K L1 L2 1). K is use to couple L1 and L2 and 1 is 100% coupling. I hope this helps. RF Man

[@TheRobgee1965]

might be little of subject but can u show how to match a vavle output ie pl519 which it says 2.5K to 50 ohms at 51 mhz

[@rfmanchannel6915]

Sorry, I don't have the equipment or Spice models for this type of analysis. Regards RF Man

[@shehabeldinahmed1156]

28:14. why missmatch i dont understand this point

[@ditditdog]

Great FB thanks 73 HANZ YL3JD

[@nagasainathkoduru9995]

You didn’t showed how to calculate transistors input impedance

[@Davidsmith218]

What am I doing wrong

[@user-ij1lh4eb1e]

Hello, my name is Sam. I designed a HF transmitter circuit. And I have a problem with the antenna that I explained in a video.
Please let me know if you have a email address to send it to you.
thank you
Best regards

[@rfmanchannel6915]

Please visit my web site at rflinear-amplifiers.com