About

“The Signal Path dot com” has been established by a few of us as a part-time project. Our goal is to help new students and hobbyists familiarize themselves with testing equipment, testing procedures and circuit design. Furthermore, we hope to introduce various test equipment to the market and help manufacturers advertise their new products. “The Signal Path” in a non-for-profit website. Please feel free to contact us with your suggestions and feedback.  If you would like to send us an equipment or part for review and demonstration, don’t hesitate to send us an email to hosts@TheSignalPath.com.

People Involved:

Shahriar Shahramian's Photo

Shahriar Shahramian

Shayan Shahramian

Shayan Shahramian

41 comments

  1. Steve says:

    Fantastic blog. I love the detail you put into your videos/experiments. I’m an aging EE and you have no idea how amazing the tools you have available to you these days are.

    I would love to see you do a detailed video on some of the microwave PCB stuff – you looked through the USB microscope at the inside of some *very* interesting gadgets – the transmission line stuff that is inside these things are such marvels of engineering. My guess is you could make it seem almost easy! Do a quarter-wave transformer or impedance match on a PCB and demonstrate. That would be fascinating.

    A detailed tutorial on IQ modulation with the CDMA stuff and cellular use etc. would also be great.

    You are amazingly talented and I hope for nothing but success for you and hope that this blog will continue.

    SSM

  2. Simon says:

    Hi there!

    First of all, I would like to say: Keep up your great work!
    Although there are other “famous” blogs (e.g. EEVblog) on the net, yours is more advanced in terms of technical aspects and professional background information and not that “popular science” stuff …

    Anyhow, I have a question:
    I have some trouble with finding the right connector / adapter for my sampling oscilloscope (Tek 11801C).

    The sampling heads of this scope have “precision SMA 3.5mm” inputs. And here starts my problem: I don’t know what kind of cable and/or adapter I should buy.

    I don’t need the RF – performance of the precision SMA connectors. For my application, standard SMA would be fine. As they are mechanically compatible with the precision ones, one could say: okay, just screw them in … But I’m afraid to damage the sampling head inputs.

    My fist though was, to use some kind of adapter: precision SMA SMA
    But I was not able to find one (eBay). Next, I thought to buy a precision SMA cable (e.g. SUHNER Sucoflex 100), and then rip of one connector and replace that with a normal SMA to get some kind of adapter kabel for daily work … but I’m unsure, if I’m able to mount a standard SMA onto an air-insulated cable ?!

    Can you give me a hint? How can I build a “connector saver” cable for daily work? What kind of adapters / cables you are using?

    Maybe this aspect gives a nice follow up video of your initial video on RF stuff (“Tutorial on Microwave and mm-Wave Components and Modules” 7/2013) …

    Best, Simon

  3. Michel says:

    Hi Shariar,

    Love to see tutorials on PLLs and mixers when you get a chance

  4. Mark DeArman says:

    Thanks for another great video. I am always excited to see you publish the next one. Unlike a lot of other EE related video content available on the the Internet, I like that your videos are long and complete; They always remind me of TAs teaching labs in college. Hope you have the time to keep it up. The EE/DSP/ATE/etc. field is so diverse now, it is great to see videos about other areas of the industry. Thanks again, Mark.

  5. Sheldon says:

    I saw your tutorial and experiments on Magnetic Levitation. I am very interested in this project. I have sent you email about this. Can you reply me? Thanks a lot.

  6. Michel says:

    Shahriar, I got addicted to your blog last year, it is great. Now I’m having withdrawals! Probably busy with other stuff, hopefully you can update soon.

  7. David Grey says:

    Hi,Shahriar, We have not seen or heard from you with your featured programs on Various topics you have had running.Are you ok and I hope you have not had any sickness with you or your family over the past months or is it simply a case of to much work and not enough time which effects us all during the coarse of a year.
    Over the last 6 months or so I have been Exparimenting with the DVB-T dongle which they use for digital TV but can also be used as a very simple spectrum anayliser.The cost of the dongal is only round 30 New Zealand dollars.If possible on one of your forums I think that is the correct term that you could actually be able to tell us how senistive in terms of how many microvolts it takes to see an actual signal they now have an up converter to go from low frequency round 10Khz up to around 40 mhz which is the low end of the dongals frequency range.

    Hope to see you again on yournforum very soon David Grey.
    If you have any questions related to the dongal reply to me on my email.

  8. Zucca says:

    Hello! Your videos are incredible, thanks! I would like to buy your entire lab. Greetings from an Italian EE eng.

  9. Barry says:

    So glad that you have a website that is linked to my non logged in youtube account. I will view and post comments from here from now on.

    thanks for a wonderful website.

    Barry

  10. Petra Gant says:

    Hi Shahriar

    The videos are good but please remember that not all electronics engineers are guys :)

    Hello from Hungary!

    Petra Gant

  11. Mark says:

    Hey Shahriar,
    Love your work! I am a bit of a newbie in the electronics area, altho I have been doing Auto Electrical repairs for 9 years and recently got my Certificate 3 in Auto Electrical.
    Electronics is a facinating field and sites like yours, EEV and others really help people like myself to learn, understand and feel confident in repairing electronic devices.
    I have been on the EEV blog asking about Oscilloscope earth leads, devices without an earth circuit (at the power plug) and how to do testing without blowing fuses, diodes or the oscilloscope (Rigol 1052) I am still a bit confused! Some have said that you don’t need to hook up the earth lead and can do testing with just the probe on an IC to test for duty cycle etc, but I am struggling with the concept that you don’t need an earth to complete the circuit. Coming from the Automotive field, this goes against everything I know about circuits. Maybe I am just not reading it right! Help!

    Also, just like other comments, could you share a bit more about where you are (Australia?), you mentioned that you work at Dell? It would be interesting to find out a bit more about where you work and your personal lab.

    Keep up the good work – even tho a lot of it goes over my head, it is sites like yours that make me want to learn and progress.

  12. Dwight_Chroot says:

    Lucked into your your Passive Filters/Data Transmission/Equalization video researching electrosmog mitigation instruments/techniques/materials

    I really appreciate what you’ve done here, and I have a suggestion/request.

    I had one semester of college electronics, and had a great instructor, but I can’t go back to school. But I’m good at self training in technology(ASE and A+ that way), and what I’ve prepared for self-training electronics lab is hoard a bunch of old rear projection big screen tvs. I’ve repaired some flat screens , cured them of capacitor plague and common failed IC’s boards like rectifiers,

    but what I want to do for my educational benefit is troubleshoot these old TV boards because they do have IC’s but they also have standard macro circuitry and there’s a lot of common circuits and subsystems on these and I want to know those, should learn them easily by troubleshooting them.

    It’d be harder to learn anything with boards that are all surface mount IC’s I think, because I doubt the manuals give schematics to those, I’m expecting decision trees and dumb instructions(like manually testing a car ECM by probing the harness but worse-)

    I may be wrong, but the point is could you demonstrate the right way to probe a similar circuitboard on something that’s easier to obtain as junk than Lab Instruments? I’ve made some risky assumptions with all that, but I hope it kind of makes sense what I’m trying to do even if I earned some rotten fruit…hehe.

    And Hello from Tulsa, and thanks!

  13. Mike says:

    Hi Guys,

    We are just discussing over on the EEVBlog how your videos give us all a big case of test equipment envy!

    I would love to see a video one day just about the background behind the Signal Path Blog. Maybe a tour of your workspace and equipment, what sort of things you generally work on professionally and with your personal labs, what equipment you’re looking to get next, etc.

    I like the content of the videos, but it’s the equipment that makes my jaw drop :)))

    Glad you are back “on the air!”

  14. David Grey says:

    Hi I have not been able to leave an answer on any of your teaching videos at all U Tube does do allow me to subscribe to your blog.Thank you for spending the time and effort producing the information and materials on your blog.Could you reply to me on personnelly if possible if not dont worry. I envy your Lab setup wish I could do the same at home,The equipment I use is fairly outdated and manufactured by Marconi and designed back in the late 60’s. I have a kit built spectrum anyliazer from an electronics magazine using a tv tuner.
    Regards David Grey.

  15. mohsen says:

    Hi shahriar
    I wanted to interface a dvd-rom Pickup head in some project but cant find any circuit or tutorial on that please help me

  16. Jason says:

    Shahriar, thank you for the videos- i watch then to learn your work process, anyhow i am only a novice and I am upgrading from an Arduino UNO to the Arduino DUE, and need a power supply for my lab (kitchen table)… What are your thoughts on the new DP800 series from Rigol? I used a 555 timer chip to create a charge pump for a negative voltage expirement, but I wonder how much a person really needs negative voltage in the lab – I have yet to actually need it…. Do you find yourself using it often? Is it something you could do without? Lastly, what is the benefit of having all three channels positive on a power supply?

    Thank you,
    Jason
    P.S. I promise, last question, should I just use “wall warts” and make my power supplies and spend the money on a very nice DM3068 ? Thanks, I appreciate your advise!

  17. Minna Millet says:

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  18. Ahmed Musa says:

    To whom it may concern:

    It is amazing what you are doing. Thank you sir. I have an Osiliscope and wants to get my Rigol Spectrum Analyzer.I am afraid to damage it as I heard a newbie could easily damage those expensive hardware. If I may request is to add videos for the following: 1- How to use a Spectrum Analyzer with an experiment perhaps getting the frequency response of Band Pass filter and also an experiment on how to read the spectrum of a signal. What is span what is center frequency. 2- What you should do and what you shouldn’t do with these expensive hardware (How now to damage it because of the wrong input signal) Thank you :)

  19. Jeff says:

    Just watched your video on polarization control. Great work! The video left me wondering what other obscure instruments you have lying around… Perhaps a video on “Tour De Lab” is in order?

    • Shahriar says:

      I think during the last video (on class AB amplifiers) I did a quick lab tour. I have a few ideas I still have to make videos for. Don’t worry, I always try to pick interesting topics! ;)

  20. harold housen says:

    how do I become a member

  21. christian says:

    To whom it may concern,

    Greetings, I wish to begin by introducing my self; my name is Christian and currently an electrical engineering student at Florida International University. I recently viewed one of your videos on youtube titled “Tutorial on the Theory, Design and Characterization of a Single Transistor Bipolar Amplifier”. Before I get to the point of this email I’d like to add that I consider myself a highly dedicated student as well as ambitious. I’m currently taking level 2 analog electronics and I am having serious trouble on the calculations of what size capacitors to use for power amplifiers, class a and b. This has been eating me alive for the past week and I can’t seem to figure it out. I saw on your video that you chose a capacitor value to give you a BW of 20 khz and you stated for the viewers to determine the other capacitor value, which is why this email is being sent to you. If you can, do you mind explaining how do you calculate that mathematically? In addition, the other problem I seem to have is determining the input impedance and output impedance for a common emitter amplifier. Also, in your video you stated that the Beta was =100. Isn’t Beta = Ic/Ib. If you don’t mind please specify how you achieved your result. In conclusion, I’m very eager to learn this process as soon as possible. I have tried consulting my professor but unfortunately he rarely ever has time to explain such a tedious concept. I apologize in advance for any inconvenience and trouble, I would be highly grateful if there is anyway you can assist with this issue I’m dwelling. Either a short video or a simple email will be perfect. I understand you gentlemen are busy and might not have the time to contribute. Thanks again for your time.

    sincerely,

    Christian

    • Shahriar says:

      Dear Christian,

      Thanks for the kind comments.

      Let me first tell you that these concepts are not necessarily simple. Meaning that, it is normal to take some time to fully understand them. First, before you worry about frequency response, familiarize yourself with the difference between “DC Operating Point” and “Small Signal Analysis”. I feel that you have some of these issues confused. Start from there and let me know how it goes.

  22. Joachim says:

    Hi Shariar & team,
    can you do a vid about math foundations for fourier analysis for beginners and hobbyists? Would be great.

    Greetings

    Joachim

  23. Technoholic says:

    Great Work.Very helpful for Enthusiasts and Professionals at the same time.You don’t get this to learn this in schools these days because of more emphasis on theoretical learning.Please keep it going

    Best WIshes

  24. Ken Condon says:

    Hey guys,

    I’ve been watching a couple of videos and felt the need to personally thank you for the great work. I’m a junior EE student and the technical level of the videos has been perfect for being introduced to topics that we haven’t hit on in class.

    Thanks!
    Ken

  25. Mohammad says:

    Thank you so much for dedicating your time sharing your valuable knowledge. Your videos are really helpful for me.
    You know, we are suffering from lack of practical experiments and courses, specially those RF and accurate measurements in universities here in Iran.

    Wish You The Bests

  26. What a fun resource. I stumbled across this site accidentaly as one of the blog posts came up on YouTube after a video I had been watching. I use many of the same pieces of equipment in my lab and it is always interesting to see how others do things or approach a particular problem.

    -Thank You, Kenneth

  27. Ken Crane says:

    I just wanted to add my kudos to your efforts in the youtube videos. You do a really good job of explaining what you’re looking for and how to go about troubleshooting this very complex equipment. Your discussion about rf stuff is over my head as I’m into mostly analog audio. But I really appreciate the time you take to explain the circuitry. I tend to freak out when I encounter things like ASICs and other unobtainables but you have given me hope. Thank you. BTW, how come I only seem to find old Radio Shack junk when dumpster diving?

  28. Roland Govantes says:

    Greetings Shahriar,

    Your mastery in electronics allows the video viewer to comprehend, visualized and journey with the wondering electrons through a maze of active and passive component easily with respect to time. The way you present each subject and the caliber of each video is the secret to your success.

    As an electronic junky I can’t wait for new videos.

    Continue your excellent work.

    Cordially,

    Roland.

  29. Nemanja says:

    Great blog! Electronics is my hobby and this blog helps me a lot! Thanks a lot!
    Greetings from Serbia!!!

  30. Tarik says:

    You are great man, please continue your work.

  31. Joachim says:

    Hi Shahriar,
    cool science stuff. Love it. Now we know how hard it is to do science with that martian temp diffs for Curiosity…
    Do more of that physics experiments in the future, for example test some different acceleration sensors for the sake if they really are in spec.

    Gretings from Germany.

  32. Aljaz T. says:

    Hi guys!
    Very good video blog!
    I am student and this blog it is a big help for me.
    Keep up the great work!

    Best regards from Slovenia (Europe)

  33. Thanks for your blog post. The things i would like to bring about is that computer system memory has to be purchased if the computer cannot cope with everything you do along with it. One can set up two RAM memory boards containing 1GB each, for instance, but not certainly one of 1GB and one having 2GB. One should look for the maker’s documentation for one’s PC to be certain what type of storage is required.

  34. Nick Klein says:

    Fantastic job on the videos! I am an aspiring EE student and these have augmented my learning and helped give me some physical intuition.

  35. HarvHam says:

    Wow! Excellent tutorials and presentations! Keep up the great work guys!

  36. Santelmo says:

    Would like to say your videos are excellent. Theory and practice explained very well, got me motivated to learn electronics and dust of my old electronic books. Would like to see how to design circuits to precision or maybe something a bit complex like poles and zeros, fouriers analysis with practice. Many thanks and kind regards.

  37. Your videos are great. Is it possible to get them as video podcasts beyond Youtube? I like to temporarily download video like EEVBlog to my MP4 player so I can watch them on the bus or in the park at lunch. I don’t keep or modify them but would like to see new episodes off line. Is this possible?

    Thanks

    Gregg

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