RF Chokes - what are they and how are they used?
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- Опубліковано 9 вер 2022
- This video discusses the purpose of an RF Choke used to bias a Bipolar or LDMOS Power Transistor. It focuses on the design requirements, construction, and various testing techniques.
- Наука та технологія
A true theoretical and practical class, wonderful.
thank you very much
Awesome video sir, keep schooling the people. 73
Thanks!! Will do... RF Man
This is my buddy here man! I call him rhe Genius for a reason. His words are so valuable to me ive recorded him just as we hang out so I can learn later..... need to get back over to hang out with him. Their aren't many of him out there that are teaching and spreading knowledge? Not for 💰 or any type of gain, but because he has love for this happy and he enjoys teaching just like I do.
Another good video to learn from! I didn't realise just how much coil winding spacings affected capacitance.
This video was GOLDEN!!! This is exactly why I use 43 on all my DC Chokes Bar None! I use 61 on my RF Transformers for better core saturation characteristics which I learn from you my friend :)
Wanna chat with you soon because...im about ready to use that scope I got from you and I want to be able to read the rf voltage after the choke.
I'm happy to help you anytime my friend!
I stumbled across this channel. Wow the content is fabulous!!! Any help in showing how to set the VNA to do those sweeps would be great and also how to get the VNA software on the computer. I salute you on this content and your approach. So many people get stuck in the mud explaining it and you made it easy for the viewer that may not be as technical as a lot of people. You want me to keep learning more. Please keep the videos coming. One of my favorite sites!!!
Thanks for you comments. I am glad you fine my videos useful. Here is a link to a video showing how to download the VNA software. ua-cam.com/video/Rwm2q4H7iQA/v-deo.html
Regards
Amazing!
Thanks for your comments. I watch your channel all the time. Great content!!!
Can you show a video setting up a high q factor narrow band choke? Thanks EDIT. Disregard. I am only watching the rest now showing the nbw choke. Thank you
Thank You!
Could you please show us how you set up the NanoVNA to see graph?
Great video - thank you. One thing that wasn’t really clear in the video though was why the choke had to be a min of 500 ohms?
This is the minimum impedance needed to attenuate the RF ripple. 500 ohms is referenced in many design guideline white papers and other technical sources.
man i love you !
Thanks for your feedback. I'm happy I can help!!
That makes sense at VHF and UHF frequencies you would want more attenuation and at the sacrifice of less bandwidth which in turn increases your q factor. So it's a trade off
Hello, I assume that the input and output impedance during the measurement is 50 ohms
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The now have tiny mini versions of all these chokes - like 1/4” wide.
The size of the toroid and gauge of the wire used should be determined by the amount of current required. There are charts online that show current vs wire gauge. Regards
Is the vna in dbv or dbm? Thanks
Great Video!
What would you get for broadband performance if you double, or stack two cores together?…
Would it get broader?
I’m trying to get better power efficiency from the RF Amp of the (tr)uSDX SDR Radio.
Thanks! 73 WA4ITD
You will only see a small improvement. Regards
Help, RF Man!
Thank you for your videos!
They are so helpful in understanding RF!
Could you please give some insight for a very nagging problem with the low amplifier efficiency with the popular (tr)uSDX SDR transceiver?
So many Hams have been trying to solve efficiency issues with it but can’t get a handle on it.
Your insight could really help us out.
Thank you! 73 WA4ITD
Hello Frank, I've seen this unit on You tube. Do you have a schematic for the circuit board? I will take a look. Regards
What causes Plate RF choke in vacuum tube HF amplifier to burn
Heat ? Sorry not the answer you were looking for... is it being used beyond it specs ?
Hi good day RF man I like your videos so please keep upload I leaned from you a lot really Thank you so much
And I hope you advice me where I can buy SemiconductorsRF Power LDMOS Transistor
I find AliExpress selling MRFX1K80H for 160$ and I wandering its original please advise me Mr RF
Thank you again
It's probably a countified part. I would only buy from a US supplier (Arrow, Digikey, etc.)
@@carminecampo2045
Thank you so much for your reply
🌹🌹🌹
@@carminecampo2045
May please you can advise me , where I can buy TelePost LP-700 for
Which good store online in US
The dumb things i find everywhere, for 30 years!
In Power Amplifiers of RF, in the force circuit, THERE IS NO CHOKE.
In RF Power Amplifiers, there are no noticeable continuous curents.
In the Drain, in the Collector, of the final, THERE IS NO CHOKE, NO RF BLOCKING.
It is, or must be, if you want it to be a good amplifier, a non-blocking inductance,
must be a transmission inductance.
It does not block, it doesnot filter, and it does not let CC pass, because there is no CC.
The small polarization curent, that opens for AB regim, it is neglectable.
So, there is no CC AC separation.
It is not filtering, something else applies, to calcvulate that inductance, and that is...
The Maximum Transfer Theorem.
The inductance that you call Choke, if it is to be choke, then ideal would be infinite inductance.
However, that would kill all amplification.
The inductance must be minimal, therefore it is NO CHOKE, it is a STORAGE INDUCTANCE.
The storage inductance is part of the transmission, the main transmission of AC power.
I don't agree with the others guys. The video is turning around the subject not really explaning choke with it's physical limitation... nice video otherwise.