RF Choke Demo

RF Choke Demo

[@barn5923]

Morning Rick we do appreciate all that you do to help us to become more knowledgeable in radio electronic Thanks very much

[@saturn5tony]

Any absolutely perfect explanation of an RF coil / resistor comparison I EVER HEARD!! In 6 minutes I got an example of something I knew, but to actually see, was an excellant way! Good job Rick. When I got my degree in electronics, I would have gradualted in a few months rather than years if YOU were teaching!!!!

[@skycarl]

Another great look at the inside workings of a circuit. Chokes can be those mysterious components that work but can make you ask why. Thanks for another fun education video.
73

[@AllAmericanFiveRadio]

On the trainer there will be no signal because it is ground, all though your right there is a small amount of RF being shorted out. There will be a little RF getting into the power supply of the transmitter and I would like to show it, but I gave the AM Transmitter to SpeakerFreak95. And most of the RF will be shorted out though the filter cap. Its interesting that 150pf cap across the filter cap works better to short out the RF.

[@MrSuperheterodyne]

Fantastic video. Very very nice teaching method you have, and nice clear explanations. I am grateful for these videos! Thanks!!!!

[@rothschadel]

great vid. could you add a segment showing the oscilloscope hooked up on the other side of the coil also. It should show little RF, correct?

[@bisbeejim]

Thanks for the video. I've wondered all my life what a choke coil actually did.

[@AllAmericanFiveRadio]

Impedance is AC resistance, and it increases with AC frequency. The 39 ohms is DC resistance. That's it.

[@AllAmericanFiveRadio]

Hey John,
I've done this before 2-3 years ago, but this one is a little more polished, and it is a different example. Anyway I should have bought stock in a capacitor company before you started working on that TV.
Regards,
Rick

[@joernone]

Rick,
Fantastic. This info is vital to one of my own future vids. But you're about four years overdue. :-)
Thanks, my friend.
Regards,
John

[@GroverCricketDaisy]

Hi Rick my question is regarding the choke coil. Does the coil stop the FR passing through it due to the magnetic field that it sets up and only allowing DC through? Thanks Bill

[@AllAmericanFiveRadio]

Hey Bill, it is the Moving magnetic field that produces impedance. Here are two videos that mat help.
Impedance, Back EMF, AC Resistance
czcams.com/video/y11SbmXPY18/video.html
Impedance Back EMF Practical Demonstration
czcams.com/video/JrI7I93XzYk/video.html

[@cyberlightbeing]

The way you explain stuff is simply brilliant!

[@Pwaak]

It's a real joy watching and learning from your video's! Thank You!

[@kuizatz]

Excellent, thanks so much.

[@AllAmericanFiveRadio]

Thank you, and your welcome.

[@OIE82]

Very cool video on chokes. So I guess a choke is (can be based on freq.) to AC what a capacitor is to DC. ?

[@AllAmericanFiveRadio]

A choke is frequency dependent.

[@billwilliams6338]

ALLAMERICANFIVERADIO, Why is a CHOKE frequency dependant for what reasons?
Is the Chokes storing current like a reservoir like the filter capacitors or is the Choke doing something else to the AC ripple, not sure if the Choke is regulating the current?

[@AllAmericanFiveRadio]

Yes the choke/coil does store energy. Here are some videos that may help.
Oscillators, the Basic Tank Circuit 1
czcams.com/video/fQ4yRVEzXQA/video.html
LC Resonance Testing Demo
czcams.com/video/84WmnlKgTeg/video.html
LC Resonance Oscilloscope Demo
czcams.com/video/G_RCyDdt2rM/video.html
PI filter, Resistor Choke Oscilloscope Demo
czcams.com/video/WzwaHO6WPCk/video.html
Capacitors, DC and AC Current
czcams.com/video/NInt1Ss3vQ4/video.html

[@MyTube4Utoo]

Interesting. Thank you for the video.

[@AllAmericanFiveRadio]

Thanks

[@southernexposure123]

Thanks for the good illustration. The choke you used was about 39 Ohms DC.
The impedance of a coil changes with AC frequency, So let me see if I have this right - the importance of and effectiveness of using chokes rated in certain mH & uH is to choke AC from entering the power supply depending on the different frequencies of the RF amplifiers? And would there be any need for chokes in the IF?
Thank you
Thanks

[@billybonewhacker]

once again im learnin damn it. btw im building some of homer davidsons stuff from his book radio projects you can build.now i undetstand why all the chokes are needed. maybe you could do one on that 455 khz ceramic filter.thanks

[@GroverCricketDaisy]

Thats amazing how that works

[@AllAmericanFiveRadio]

It is still fascinating!

[@AllAmericanFiveRadio]

Thanks Mick Bradford

[@multi-talented7986]

What if I apply 1mega Ohm resistance instead of 50Ohm? Will the RF signal still short to ground?

[@AllAmericanFiveRadio]

This is a low impedance circuit to DC and a high impedance circuit to RF. If you substitute a 1M ohm resistor for L2 you now have a high impedance circuit to DC and RF. But there is no RF because the plate has insufficient VDC.

[@tommee10533]

Fascinating video sir, thanks for sharing it.

[@rolandosalgado1552]

Thanks for share , 👍

[@AllAmericanFiveRadio]

Thanks

[@eugenifibla4496]

Great Video! Very Educational. Congratulations.

[@MrUbiquitousTech]

Great demo Richard, thanks for sharing!

[@AllAmericanFiveRadio]

Thanks

[@Phenyl82]

Thanks for this videos. Always learning from you. I appreciate it,

[@vibra64]

Another great video on electronics theory. Thanks!!!!

[@danhassan2108]

It is because the back emf that the AC cannot pass the inductor yet the dc can pass the inductor right? Thank you for another concise video! you are not one of those other youtubers who does not know how to explain circuits:D

[@AllAmericanFiveRadio]

AC current is changing constantly which causes the magnetic field to change constantly, and it's the changing magnetic field that is opposing, and are blocking AC current. DC current also produces a magnetic field and this magnetic field does oppose this current, but once the magnetic field is established and has stopped moving then there is no longer any opposition to the DC current.

[@ericalbert6954]

Merci beaucoup !

[@AllAmericanFiveRadio]

Your Welcome!

[@AllAmericanFiveRadio]

Thanks John

[@AllAmericanFiveRadio]

Thanks vibra64

[@AllAmericanFiveRadio]

Thanks MrSuperheterodyne

[@YQTFun]

Could you do more on AM and FM modulators?

[@mitchellpurelife]

Thank you! Great video! I agree with Don Lewis.

[@danielpincu7743]

Excellent explaining!

[@AllAmericanFiveRadio]

Thank you, and your welcome.

[@Froggy19510]

Another great video. That's why I am a subscriber.

[@AllAmericanFiveRadio]

Thanks Phenyl82

[@jstrunck]

Nice choke vid!
Thanks,
John

[@MickLBrad]

Nice work, Rick.

[@st2nh]

Many Thanks OM

[@AllAmericanFiveRadio]

Thanks yearningsoul

[@AllAmericanFiveRadio]

Thanks skycarl

[@gurtobe]

Cool

[@AllAmericanFiveRadio]

Thanks cyberlightbeing

[@AllAmericanFiveRadio]

Thanks mrvesteraas

[@AllAmericanFiveRadio]

Thanks YQTFun

[@AllAmericanFiveRadio]

Thanks Pwaak

[@AllAmericanFiveRadio]

Thanks gurtobe

[@AllAmericanFiveRadio]

Thanks barn5923

[@AllAmericanFiveRadio]

Thanks jstrunck

[@ve2dzo]

Hi Rick
Do you have a email?
Is there a way to check a slb-1 or slb-3 diode mixer for shorts or open

[@AllAmericanFiveRadio]

Thanks st2nh

[@AllAmericanFiveRadio]

Thanks tommee10533

[@AnastasisGrammenos]

cool

[@AllAmericanFiveRadio]

Thanks.