#303 

This channel is pure gold.

I feel like enlightened! As soon as I get an oscilloscope, i will make everything you used here!

A godlike presentation Alan! You mean you don't have to count pulses. I already purchased a stethoscope!

I always enjoy your stuff. Teaches me new things and new techniques . Please don't get tired of teaching us.......

By far my favorite engineering youtube channel. I also enjoy the Boom guy, Australian Guy and the Bell Labs Microwave Guy. They all have really educational videos and very practical approaches, but I find this channel the best, none explain things so clearly. Probably the calm voice also helps. When I watch the Australian guy all I hear is screeching.

Very elaborate and clear presentation, thanks a lot ! I am interested to study and finally make some pulse-counting detectors, so I watched your clip very carefully. Congratulations! While studying the history of this type of demodulation, I discovered that there were many companies that produced FM tuners with pulse-counting. The undisputed champion is Kenwood, but I also noticed Accuphase, Heathkit and Fisher. Here are some FM tuner models equipped with pulse-counting demodulators: Kenwood 600T (1976), KT-615/815/917 and L-07TII (1979), L-01T and KT-80 (1980), KT-9XG, KT-900/1000/1100 (1981). Kenwood produced pulse-counting discriminators using discrete components, discrete+some known ICs (TA7060P, SN74LS03 or SN74LS38N, HA1457, NJM4558D) and dedicated/proprietary ICs (TR4010A and TR4011). Another FM tuners with pulse-counting: Fisher TFM-1000, Heathkit AJ-1510AS . I hope that these informations will help. Also, a good source of info is the "Tuner Information Center" at www.fmtunerinfo.com/kenwood.html . Good luck and be sure you have one more student watching your clips! :) Best 73s de Cezar YO3FHM

Best educational videos on RU-vid! Thank you again.

To the best of my knowledge including the many years I worked in RF, I never came across this type of Discriminator. Very interesting to me. Thanks again for giving me something to look into.

These videos rekindle my love affair with electronics. Thank you w2aew!

Glad to have you back.

What a brilliant demo! This is the type of project that makes me want to get back into RF engineering.

Very good explanation. I have an old Modulationmeter for AM and FM. The FM-Modulation is measured with this principle, because such a FM-Demodulator is very linear when built properly.

Remarkable video. Thanks Alan!

Alan did it once again. I said it once boys and I'll say it again. Pack your stuff because there is one engineer here and it's Alan.

Thank you for teaching great stuff. One of the best channels.

Wow!!! Perfect explained. All your videos are amazing Alan, thanks a lot.

Fascinating. It seems like digital-style circuits with switching are "unreasonably effective". they are still so useful for such an analog, frequency domain problem as FM demodulation.

Thank you for producing such great information-loaded videos. ARL 73!

Very cool, Alan. Appreciate the top notch content for my ride home from work!😊

I always thought the carrier frequency was fixed, and it was another signal that frequency modulated.. now I know better! Thanks!

Nice to hear someone who knows their stuff and speaks with confidence on a very interesting subject.

Ah the nostalgia. I first came across the pulse counter in point to point microwave links for video and audio distribution. One thing I can't drag out of my memory is that we were told the pulse counter was inherently 3dB less noise than a Foster Seeley, but I am damned if I can remember why.

I am amazed by your explanation skills. Thank you.

Another mystery unveiled for me! Thank you Alan, always a great pleasure to watch your videos. I even downloaded every video you posted for me to watch in case YT goes down. I said it before and I have to say again: you are a treasure for us. Thank you, prof. Alan Wolke

Thank you, for another selfless gift to the world. You are absolutely the world's best teacher on RF design topics.

Thanks Alan for yet anotber delightful video. The format is just perfect, finely polished. Nothing needs to be added or taken away. :-) Every bit of it is enjoyable and the sum makes for a really efficient learning tool. Knew nothing about RF before I started watching your videos and those of Shahriar/TSP, but I am glad to say that your work paid off. I am now no longer afraid of mysterious looking shielded cans....for the first time last week I had the opportunity to be confronted with the stuff ...albeit to a modest extent....FM radio reception in my 20 year old car was horrible. Car has a preamp sticked to the base of the roof antenna. Yeah, a shielded can ... I thought yeah let's open it see what's inside this thing, maybe I can fix it ! And yeah I was lucky I could fix it... Just yet again a bad electrolytic cap ! LOL But whatever, point is I was not afraid of opening the can, and took pleasure at studying the board to see how it's put together, armed with all the knowledge you and Shahriar dispense ! Anyway, all this long winded post just to thank you for taking the time to produce such marvelous videos. They are very efficient and enjoyable, extremely appreciated, and as I tried to illustrate above....they actually produce positive results :-) It takes work to produce such well crafted videos so I don't know how long it will be before you get tired of it, but even if you were to give up tomorrow, I would still be very grateful for all the videos you have done so far ! :-) I see that you are now past the 100K subscribers, quite a milestone for a niche channel like this one. This means people really see value in your work, so I am hoping this will keep you motivated and that we will be able to enjoy your little gems for a little while :-) Greetings from Frog land, Vincent Trouilliez

It's pity you don't produce videos so often ... I love your explanations! As always superb video! Thank you so much.

Thanks a lot Alan. Please don't stop! You make a lot of sailors better aviation electronics technicians!

Thanks Alan! Nice video! I can't believe that some jerk disliked this video!

What a great little tutorial. This explanation makes it very clear. Really makes sense now.

waw..., I am always amazed at the clarity with which you can explain every subject you touch upon. Thank you very very much for these videos! All the best from Belgium!

Love your videos. Very straight forward and clearly explained!

Well, this is quite an elegant solution. Sure I have to build a railroad communications receiver this way. Russian railways use 2.130 and 2.150 kHz FM channels so I could simply build a fine receiver using ferrite antenna with differential RF amplifier IC and circuits shown here. Great job, thank you. 73 de R2ATO!

Great explanation and demonstration Alan. Enjoyed it very much. Thumbs up

What a great job! Crystal clear explanation from beginner to expert. Thank you very much also for the link from VK2ZAY.

I used to demodulate FM with quadrature fm demod or pll circuit ,by reading the output dc voltages ,THANK YOU aLOT

I am always looking forward to your videos -- you are the only one where I asked youtube to notify me :-).

Best videos on RU-vid! Watched this video 3 months ago with the intention of improving my radio building skills. Was my first introduction to pulse generation. As I learned more about PWM circuits, I got side tracked and made a modulated carrier IR circuit and motor control circuit. Eventually, I'll be ready to make a Pulse Counting FM Demodulator. Thanks for sharing and educating us!

Absolutely exquisite video ! So pumped to go to my own little lab and spend the weekend there ! Really enjoyed this video.

Very informative video. Helped me visualize demodulation and how exactly it is done.

Alan, always great stuff. I’ve never attempted to build an FM receiver from scratch, but this method looks so simple.

You keep me learning new stuff thanks to your excellent videos. Thank you !

Very enlightening. I have a Heathkit AJ-1510a tuner which appears to use such a detector. Integrator/amplifier uses a 709 opamp; I want to see if a better opamp will improve audio quality.

As always educational and entertaining. Thanks.

I realy love your way explaining things. Thank you for spending time on it. Dick Netherlands.

Really you are the best to explain things. It goes straight into mind. Pulse counting technique is really interesting. Thanks for all your efforts in making this video.

Thank you for this excellent vídeo, very well explained. Greetings from PY5ZWS , Brasil.

It'll never be said enough, but thanks for putting up such quality content, man. You've helped me through my undergrad to grad to real world work experience - even if what you've posted is not directly applicable to what I'm working on. The explanation of your content is superb. It's something to emulate.

Outstanding as always. Clear, concise explanations and interesting content.

Very clearly and well explained.

Useful video. I like it

Fantastic video Alan - as always. I found this at just the right time as I'm playing with fm modulation and demodulation for the first time. I built your circuit and was amazed at how well it worked. I'm looking at building it into a larger receiver like VK2ZAY. Thank you so much for explaining so well. 73 Nick M0NTV

Oh man, that is good stuff. FM demodulation has always sort of mystified me and that goes a long way towards making the picture clearer. I'm definitely going to take a stab at building one of these and testing this out!

Finally got my TA2111 chip project operating in FM mode. It's been my practice stage to gain experience combining the Osc and RF coils with a ganged capacitor as Alan has suggested. It's been much harder than an AM receiver! I think I'm almost ready to try the pulse counting FM receiver...

A real experts pointer. Tek.

Nice MDO and nice demo!

Thank you for this video sir, really very useful and interesting, thank you for your time and effort.

That was very interesting. Never knew there were multiple ways to discriminate FM. Cool stuff!

Great video. Thumbs up. This actually could be a pulse counting FM demodulator if the pulses were fed into digital circuitry which calculated the time between successive pulses (i.e. the instantaneous period of the output) and the reciprocal of this would then be the instantaneous frequency which represents a voltage at that point in time.

Awesome video, thanks for sharing this technique - I always learn something from each video you make

Brilliant, I'm alway looking for different ways to come do things .

Your notes are great!just don't forget to take a break sometimes, tech, computers, etc is more addicting to me than ANYTHING!!!!!!

Great explanation and video as always Alan. Thanks for the shout-out to my old receiver project too!

Loved he signal source material at the end! :)

Clear explanation and demo as usual, great stuff, thanks.

Great video. There is also another reason why we need to down convert to use this demodulation method, and that is it is very difficult to generate sharp pulses with low duty cycle at high frequency. For example for 100MHz signal, you need to generate pluses with 1ns or better ( Lower pulse width) and then integrate them. Of course, you can use say 20KHz bandwidth integrator (bandwidth of sound or info) that is not hard, but generating 1ns pulses or better is hard, but not impossible. Maybe, this is another way of direct conversion receiver.

Innovonics used this method in their broadcast industry tuners such as their 530 modulation monitor. They take the broadcast band down to the very common 10.7 MHz first IF. Then they drop that by 10MHz leaving a 700 kHz 2nd IF, ideal for the broadcast band. A fully loaded broadcast station with stereo and RDS at 100% modulation, +/- 75kHz in North America, is 253kHz occupied bandwidth. 700k is a pretty good number. Well implemented this method has extraordinary fidelity.

Enjoyable video, thanks for sharing, it gave me a lot of information that i didn't know. Thanks

Good to see a new vid - excellent as always.

i always enjoy your stuff!!!!!...thank you for ur help tnx sir keep it up!!!!

Very good explanation, very interessting, thank you for the video

Great stuff! This is a new one for me. Great job as always. Thanks a lot.

You are a magician! Love your videos!

Would love to see more radio circuits analyzed by yourself .. Thanks Again....

Very interesting Alan! Always enjoy your videos. I am also working on FM receivers (see my channel), but did not know this method of FM demodulation yet. I’ll certainly give it a try. My preferred method at this moment is using a crystal filter and tune the IF to be on the slope of the filter.

Thank you for an interesting video. The IF filter cannot remove the image. There are always two tuning points. I have used this technique for 2m FM reception. Also there was a tiny pocket FM receiver made by Sinclair in the UK in about 1970.

The more I try to understand radio or electrical theory the more I'm convinced that it's literal magic

I have a Kenwood KT-815 receiver, which uses a pulse count detector. Both the specs and the sound are excellent. Belar uses the pulse oount detector in their FM modulation monitors, --de N3TPS

A very classy pointer !

I made pulse count FM radio... sounds is good and circuit is simple ( good for beginners ). dont need special measurements and settings ( like a clasic discriminator circuit )

Awesome video. Very well explained

This is actually the first time I see RM being used for practical (rather than sound design) signal processing... My background is basically not electronic so I still need to learn a lot. Giving that this is already the 303rd video I guess I have a lot to catch up then :)

That ”Remarkable” tablet looks amazing. Love that you can have graph paper as a background. Can it do smith charts too?

I always enjoy your videos, but I have to ask. Are you secretly Forrest Mimms III? Whenever I see you draw everything out on the graph paper it brings me right back to the little paperbacks from radioshack.

Thanks! was so much interesting. Please take care of yourself and upload more often 😁👍🏻

Thank you, excellent video

Lots of good info. Thanks.

Great work. Thank you

fantastic! thanks!

Good job dude 🙏🙏🙏

Thought about using a digital function like a Schmidt trigger for the limiter function? Really like all your postings.

Finally a fm demod i can actually build

Excellent! Thank you

I've been thinking of something similar, if I could use the FM modulated rf to change and alter the freqency of a square wave oscillator, then simply by integratigration of the edges (via a small capacitor and r ) [I'm a great fan of Shmit triggers , namely using a coil instead of a r in the feedback! ] obtain pulses praprtional to the modulation frequency. Using say the +'ve pulses and then average out to obtain the Af !

Great content, as usual. What tablet/software are you using? it looks very nice and readable.

Great video.

A very interesting FM demodulator. Do you think it would be an issue to have the LO tracking the RF frequency so closely? I guess one consideration would be to have the LO not sitting on the next upper or lower FM channel adjacent to the one being demodulated but somewhere between the stations... As always, another pure gold video. Stellar stuff! Cheers,

The bloody thumb is to freaking small! Thanks Alan! ✊👍👍👍👍👍

Awesome video .. I have to ask though, what tablet is that?

Thanks for another great video - I wish I could give 10 thumbs up :-)