Since the creation of The Signal Path video blog in May of 2011, I have focused on producing the type content which is either difficult to find or difficult to learn. Despite being the foundation of human communication, RF and microwave electronics often seem like magic and my goal has been to demystify these concepts. The Signal Path blog provides a rich depth and breadth of electrical engineering topics and experiments. Equipment reviews and repairs are always accompanied with research and industry relevant experiments and tutorials. The aim of The Signal Path is to provide free education to everyone across the world, possibly the greatest gift from a human to another. Any support you offer to The Signal Path will be put back into lab maintenance, improving the quality and frequency of video production and acquiring components to further diversify content production. As of June 2023, The Signal Path has produced over 200 hours of original material.

You can support the channel through Patreon or PayPal:

Contact: TheSignalPathBlog@gmail.com

Shahriar Shahramian's Photo

Shahriar Shahramian

Shayan Shahramian

Shayan Shahramian


  1. RajN says:

    Hi Signal Path Tech Master ,A regular viewer , Great works from you in Tech Domain. Hats of to knowledge background. Fantastic presentation. Well noticed in many comments and appreciations.

    An use guidance about SAMPLE RAM fail in Agilent 89440a/89410A instrument. Module replacement shows pass/fail. How to replace faulty chip on A55 Sample-RAM module. thks.

  2. bruno says:

    Hello Shahriar Shahramian,

    I have a anritsu site masterS331A with problem on the output RF, the amplitude of signal is going up and down(-20db to -40db).

    can you help me?

    thanks a lot.

  3. John S says:

    1st, love the show. I have learned a bunch from it. Especially from the 3458A repair and the E440x spec. ans.

    now, as a calibration technician, I come acrossed many challenges. The latest is trying to figure a way to detect the oscillations of a crystal oscillator in stopwatches/timers. I know its typically around 32kHz. I keep seeing mentions of acoustic sensors, inductive and capacitive sensors and even piezo and ultrasonic sensors. I know that no matter which sensor I will need some type of amp to boost the signal to be measures by a counter or o’scope. Can you point me in the right direction?

    Most time base measurement systems are not accurate enough nor have enough resolution for the more modern stopwatch’s

    this reference has help me get an idea of things and also confuse me…


  4. O.R.Mitchell says:

    I just viewed your very interesting teardown of the Bluetooth enabled COVID-19 in-home test made by Ellume. Would you happen to still have the products around and can provide the FCCID information that maybe imprinted on the bottom of the device itself or printed on the box or in the manual?

    Thanks, in advance, for any help you all can provide!

    Please eMail your response to the provided address…

  5. Juan Loera Albarrán says:

    Hello Shahriar.

    You are awesome. I want the experiment that you did in The Signal Path #22. I can’t find the circuit’s squematic. Could you tell me where it is?

    Have a nice day


  6. Pablo Diniz Batista says:

    How nice your site. I’m researching in the field of Physics in Brazil and recently I decided to maintain some equipment present in laboratories. Many stopped for a long time. The first was a lock-in amplifier. I thought about making some videos for Youtube in an attempt to encourage maintenance, but I see you’re doing it very well. Congratulations.

  7. kinomatic says:

    Hello, ive been watching your videos for years and am a fan of your approach to instrument reviews. from teardowns of the instruments, schematic walkthroughs to real life tests using the equipment under review your reviews of high end test equipment are some of the most thorough anywhere and i thank you sincerely for your work .

    i recently came across a german instrument manufacturer: aaronia, with some very interesting products. i have seen some recent reviews on youtube of their usb spectrum analyzer the spectran v6 x and was wondering if you could be able to carry out a review of this product too. since there are very few reviews of this manufacturers products online it would be great to have you analyze how the product works and then see you put it through its paces to see how well it performs especially when stacked up against the claims of its manufacturer. from my interaction with the company they are very responsive to emails and i even had one of my questions answered by the ceo himself! so they could be open to sending you a review unit.

    this is only a humble request from a viewer and hopefully, you will be able to have the time and interest to cover this analyzer. Thank you and keep up the good fight.

  8. SANJAY RAWAT says:

    Hi.dear how can I contact u

  9. Morteza says:

    You are the best.
    شهریار جان دمت گرم

  10. Victor Micha says:

    Hi guys!.

    I saw in Youtube your wonderful video regarding a magnetic levitation device. My understanding of electronics and circuits unfortunately is minimal…
    Nevertheless less I was as kid a passionate aeromodelist. Since then I have an idea of a project that I believe would be very interesting in aeronautics. ( I am only a naive and humble hobbyist ).
    Is there a chance of contacting You guys in a personal fashion ( say via zoom) to let You know the highlights of it and see if You would be interested in collaborating?

    Best regards.

    Victor Micha.
    Mexico City.

  11. tec says:

    You are great guys! Love the videos you are making and the professionalism and lovely humour.
    Thanks for inspiring me to do more RF stuff again! Keep up the great work and cuddles to Pooch <3


  12. Richard Badishkanian says:

    ARMOs ! Fellow Armenian Tech Freaks!! Eench Bes Es.

  13. armin says:

    It seems that Shahriar is making a video on starlink RxTx ground dish teardown and analysis!

  14. vasile.gavriloaie says:

    Hi Shahriar,
    I want to repair an Agilent ESA 4407B and is about the UNLOCK problem with the oscillator. I want to know if you can sell this documentation , electric schematics , CD schematics and all about this spectrum analyser

    • Hi Shahriar,
      I want to repair an Agilent ESA 4407B and is about the UNLOCK problem with the oscillator. I want to know if you can sell this documentation , electric schematics , CD schematics and all about this spectrum analyser. In fact I made this aquisition from ebay , like a fault spectrum. And finally i discoverd is about YIG oscilator , PLL for stability but i don’t have schematics at compoinent level to see what hapeens there . For this i asked you if you can send me this schematics , if it is possible.

  15. Homy says:

    Hi I am a research student and unfortunately my working FSH 3.13 (with tracking gen) died on me. I tried replacing the battery by purchasing a Fluke BP190, but no luck. Any recommendation on where I can buy parts for the FSH 3.13 or any good reliable and low cost repair shop as I am a student and cannot afford the fancy charges that most shops charge.

    • Sam H Reaves says:

      I have repaired few of these. If the problem is in the DC/DC converter PCB there is a good chance that it can be fixed. However if it has any issues with the RF section or needs calibration things get more difficult as board level schematics are not published by R&S and the calibration must be done using software that R&S keeps closely guarded. Those two are a couple of the reasons I have started to avoid R&S gear unless I can pick the instrument up for a song I normally don’t buy them. I have three R&S FSH3’s but only one works perfectly, the other two either need parts I can’t get or need cal. IIRC when last talked to R&S a cal cost S900.00 alone. I can easily buy a calibrated one for that. I can probably fix yours if the issues are as above.
      First off you did not say where you are located. If you are in the US it will be much easier.

  16. Matin Zaki says:

    Hello dear Shahriar,
    Thank you for your efforts..
    Please make more videos about fundamentals of MW Engineering
    I know there are videos about this subject on web, BUT your teaching style is second to none!!
    Again thank you for these impressive educational content..

    Matin, Alborz, Iran

  17. Seyfettin Devrim says:

    Greetings Shahriar,

    a big thank you for all the wonderful work you do. Everytime i watch your videos i feel pretty much ahead of myself and realize that i should push myself even more and to keep up with my electronics knowledge. I also had an idea for a tutorial if i may call it like that. I recently learned that the individual rise times of each component in a measuring chain must be added geometrically, since they have a statistical characteristic.

    Best regards


  18. Steve says:

    I’m enjoying your videos. I worked for HP/Agilent doing pre- and post- sales support of microwave instruments in the Contact Center, but we never opened them up in that function. It’s interesting to see the insides!

  19. Jerry Stern says:

    I bought the Siglent SVA1032X after seeing your review. I have it now for a few weeks and seeing some odd behavior (noise) in VNA mode not evident under same conditions in the SA+TG mode. Could I send you some screen-shots to see if you had any insight from your teardown and evaluation?

  20. Awang Azman says:

    Hi Shahriar,

    Thank you for sharing your knowledge on electronics test instruments. I have similar Model N52031A PNA-L 300hz-20Ghz in our RF lab. But the front panel keypad ( front USB port is also not working) is not working. I suspect the U4 or U20 is fault. U4 AN2131QC and the U20 AT43301 hub controller. I have search via google and can not find the circuit diagram for the front panel control board. I have try to boot and reboot the network analyzer still the same problem.

    Electronics Lab Tech.

  21. richard kaltenbach says:

    Wow and I thought I was the only one crazy enough to attempt to fix stuff w/ no documentation on a non- supported product! awesome videos, I just saw your site as I have a Rhode FSH-8 with display issues and your site came up as I was looking for the R&S site to have it repaired (again)I love RF, it’s my specialty..cant afford to buy expensive spectrum/network analyzers so I do the eBay thing too! usually with good results..I know the feeling when you take something apart and you see it’s history unfolding around you (not usually a good thing 🙂

  22. Steve Kirkby says:

    Hello Shahriar,

    I always look forward to watching a new video from you and have learned a great deal. I would love to see a video explaining the ins and out of different RF switching techniques — electromechanical, diodes, mosfets and any others I haven’t heard of. I know that Alan (w2aew) has posted some videos on switching diodes and pin diodes, but an over all look at the field (with some experiments) would be great.

    Keep up the great work, and miaows to Pooch.

  23. Binayak Shrestha says:

    Hi Shahriar,

    Thanks for the service you are providing to the engineering community. I deeply appreciate your efforts.

    Teledyne Lecroy has recently launched “WavePro 804HD-MS” – a 12-bit, 8 GHz, 20 GS/s, 4ch High Definition Mixed Signal Oscilloscope. They specification shows lots of promise! I am personally finding it to be on par if not better than Keysight Infiniium S-series oscilloscope (MSOS804A) for high speed signal integrity purposes. What are your thoughts? Any plan to do a teardown video for this new oscilloscope?

    I love your videos! Keep them coming brother!

    Take care,

  24. George Papanastasiou says:

    My Great Respect
    I was watching your video on Teledyne-LeCroy 100 GHz scope. Mr. Peter J. Pupalaikis & associates paper on the issue is available on the web (IEEE BIPOLAR / BICMOS CIRCUITS AND TECHNOLOGY MEETING 2014). Also had a look at Simple Down Converter Design by By Bill Pretty May 28 2007 (oscilloscope BW extension).
    So you people keep us thinking and dreaming…. That old spectrum analyzers, let’s say HP 141T are very cheap in ebay. Their HP 8555A 0.01 to 18 GHz plug in unit has three IF outputs: 1.5 Ghz 550 Mhz and 50 MHz amplitude normalized and calibrated. Their Freq, scanwidth, BW etc setup is 100% manual and they also go zero span with just a button.
    I would ask you to spend some of your precious time to comment on what would be the result of trying to pass these outputs directly to an oscilloscope?
    Would an old radio amateur like me having old staff in his junk box (HP 8555A, HP 8672A TDS 620A) end up with a poor man’s oscilloscope capability up to 18 GHz?
    George SV1LJU

  25. Rassoul Aleshi says:

    I was impressed to see your talent in teaching fundamental electronic circuits in plane language. Thank you for your contribution. Cheers

  26. Kai says:

    thank you Shahriar for your Videos, i like it ! i wonder where do you get the instruments for repair from
    ? i search also the web but such nice things must be a special source 😉 perfect !
    best regards

  27. Ivan says:

    Hi Signal Path
    someone said that when designing antenna RF oscillators with High frequencies and Impedance, the FR4 PCB do not work, have you made a video about different types of PCB with impedance and and why you can’t use some types pcb to some applications ?

    ps. I like your videos, I generally like everything with RF end electronic, that why I become a Hamradio operator about 20 years age

  28. mohsen says:

    i need schematic Spectrum Analyzer Agilent and hp
    can you send email me

  29. Jeremie says:

    Hell Shahriar,

    Thank you so much for all these great videos! The quality of your work is amazing. As an RF engineer I really appreciate the opportunity you provide to acquire new knowledge.


  30. Adnan Malik says:

    Hi shariar !
    I want to know how to adjust sensitivity of vhf ICom A110 Transceiver? Also pls let me know in detail. Will be highly appreciated.

  31. Burak says:

    Dear Shahriar,

    I sent an e-mail approx 3 weeks ago about the Teledyne LeCroY WS3000 oscilloscopes.

    Did you had a chance to read it?

    Thank you…

  32. Shawn says:

    Chemistry YES!

  33. Laurence says:

    Love your videos,mostly.
    One thing gets on my last nerve however. If I had a blog and called it dog blog, I would not say ‘no pun intended’ every time I used the word ‘dog’ because it does not represent a pun!

  34. Franco Veliz says:

    Hello, greetings from Peru. What book or what theme should I read or investigate to understand the constructive blocks of the spectrum analizer that you describe. Especially the analog part where the filters are, the good program depends on what you want to do or I’m wrong. Thank you.

  35. Kai klein says:

    Perfect I like the details and the time is not important for someone who like to fix e same unit.
    Thanks a lot.

  36. Gianfranco Risaliti says:

    Hi Shahriar,

    Excellent blog, my preferred, love electronics and generally RF, happy to follow you on repairs and experiments !



  37. Nick says:

    Shahriar ,

    Love the videos. Where do you get those risers for your bench. I would like to buy some !!!


  38. Søren Nielsen says:

    Hi Shahriar
    We are working on a homemade High Fidelity Class D amplifier for audio.
    It is already working, but I think some refinements could be the thing that makes the difference for this project.
    What we want to do is to make something comparable to the best of all, and for now we think we need a bit of extra noise shaping.
    None of us know how a higher order noise shaper looks like, and therefore we wonder if you do.
    I´ve seen you talk about noise shaping in DAC´s before, so I thought you also might know a bit about how to do the same in a multi feedback loop class d amplifier.
    I hope you find this interesting.

    Stay cool
    Best Regards

    From denmark

  39. be.well says:

    Hi Shahriar Shahramian,

    just to ask if you can tell me what is the reference/name of the manufacturer of the card that you used in your video with differents modulation options !!! posted in 2014 , very interesting :
    ” TSP #37 – Tektronix RSA306 USB Real-Time Spectrum Analyzer Review and Experiments ”
    Link: https://www.youtube.com/watch?v=GDcuRTOCj_s

    thank you again for your great videos.

  40. George says:

    Shariar mate,

    Can’t thank you enough for the quality of videos you put out there.Just wish that a channel with the quality of content you have, was promoted much more on the tube.
    Keep up the good work Sir.

  41. Rick says:

    Your Cat. I expected to see a picture of your cat here.
    You should put your cat at the top next to your and your brother’s pictures.
    Hasn’t your cat has helped too? Like done CAT scans of things?

  42. Russ says:

    Hi, I have an Anritsu VNA 37397A 65GHz which will not pass self test. Can you offer any advice/ tips. I have the self test log.

  43. Salman Sheikh says:

    Somebody suggested on the comment section of hackday on oscilloscopes after another person posted about eevblog’s comparison of scope this comment:

    That could be a great video for Shahriar’s “The Signal Path” video blog: FFT analysis for inexpensive oscilloscopes from Rigol, GW Instek, Siglent…

    You should consider this if possible. Thanks.

  44. Frank Pizzonia says:

    Hello my name is Frank ,I have a project that requires code on a teensy board with a matrix display with ws2812b . I was wondering if your able to do this or refer me to someone that is thanks for your time .

  45. John says:

    Enjoyable review comparing Rigol DG4162 160 MHz Arbitrary Waveform Generator to Siglent SDG5162 – having spent the prior hour watching another review comparing the 50 MHz models between the manufacturers, I was pleasantly surprised as to how different the perspectives and review was conducted. As you see electronics deeply, I hope you find time to do a follow up on the various aspects there just was not time for in this video. Regardless, your insights are appreciated. BTW, I too am way impressed with the ability of this new technology.

    Typically, applications drive the purpose, scope, and utility of test and development equipment. My perspective drives and limits not only what type of hardware to consider but also squeezing the most bang for the buck. To this end, my focus is http://botmite.com where I also offer up some practical and not so practical observations.

  46. وحید says:

    سلام دوستان.
    شما ایرانی هستید؟
    لازم دارم. از اون مدلی که از بالا به پایین کنترل میشه. میتونید کمکم کنید و مدار کنترلی اون رو “levitation globe”من مقداری اطلاعات راجب مدار دستگاه برام پیدا کنید؟
    خیلی خیلی ممنون

  47. Khalid says:


    I have come across quite a few test equipment and rf products the past couple of years through my business. It was very informative going through your “Tutorial on Microwave and mm-Wave Components and Modules” and getting a better understanding of these items.

    Please keep these tutorials coming, they were very helpful.

    Thank you.

    • onlyRF says:

      Great tuto about microwave componens. Any chance to have a tuto or experements with Network Analyser ; if you have one; about S parameters S11, S22,…etc, how to use them with RF circuits, returnloss, reflexion power, vswr…etc


  48. Christos Kalogiannakis ( SV7MTU ) says:

    Hey guys I love your videos .
    Sorry to disturb but I need some hlp here. You see I am in some kind of a problem and I am looking for a fast solution.
    can any body help?
    I own an Anritsu MS8604A and my LCD is dimming very low, the horisontial lines in the screen are are very hard to see, and the vertical are also with low light. My first thinking was to connect an external monitor but I can not find anywhere a service manual to find how to connect it, the other solution is to repair the LCD but I still need the service manual that I can not find.

  49. Michael Chroman says:

    Fantastic Series on Everything.

  50. Rob Macfie says:

    A brilliant series of videos. I saw the one on the repair of the Agilent E4431B generator as I have just bought one. However, mine developed a fault a few days ago and I find it is the 32v line that has failed. On the back of the board there are two blue chips which I have decided must be fusues of some sort. They are not resistors or inductors. Do you think this is likely and if so can you guess their ratiings (they are marked 681J on the 32v side and 220J on the 12v side – 680 and 220 mA perhaps)? I am desperate to get this working again.

    Keep up the good work


  51. Abhinav says:

    Amazing site and awesome work. Very helpful to all the electronics enthusiasts out there.you guys are doing a very amazing job.
    Sir I need your help for a project that I wish to do. I would like to know how you connected those coupling capacitors in the MAGNETIC LEVITATION setup. I saw the schematics but am not able to figure out how to connect those well I am a beginner.
    Sir could you please take some time out to help me.i have emailed you regarding it.

  52. Utku Sevincli says:

    Helpful tutorials. Thanks.

  53. john davis says:

    very good video on PM6303A LCR Meter repair

    Any chance of a copy of the LCR Meter service manual I have the User Manual

    I am trying to design a LCR Meter front end


  54. Erkan Okman says:

    Hi Shahramian Family,

    Excellent tutorials,presentations andvVery good video blog.
    Keep up the great work!
    Best regards from Turkey

  55. Stoica Adrian says:

    Hello Dr. Shahriar,

    When will see your brother Shayan in one of yours videos?
    It seems that is a guru like you in electronics.

    Thanks for everything you do for us,

  56. Sam123 says:

    Hello Shahriar, I wanted to inquire regarding the magnetic levitation experiment you did previously.
    1. Can you tell me what is the diode model number u have used (ex. 1N4007) and why did you use 100uF coupling capacitors? where it is supposed to be placed exactly in the schematic?
    2. What is the model number of the potentiometer?
    please respond. Eagerly waiting for your reply.

  57. klaus says:

    I need help, I am trying to register in the forum of The Signal Path, I am not native English and bagged hqy question “cat ?:” someone can tell me that I only understand the animal cat means.

    • Shayan Shahramian says:

      I’m sorry that you have had trouble signing up! I have changed the question to “What planet do we live on” with the obvious answer of “earth”. Please let me know if you are able to sign up now.

  58. Dalmo says:

    Dear Shahriar,

    Thank you very much for your excellent videos and explanations. It a real pleasure watching.
    You may be interested in Analog Signature Instruments to help with your repairs.
    Here it is the link for a free open source instrument http://analogsignature2.wix.com/analog.

    Please, keep up with the wonderful videos.

  59. lorincz huff says:

    Could you provide the matlab code for your video titled “Tutorial on the Theory, Design and Characterization of Nyquist Digital to Analog Converters” ?

    Thank you in advance

  60. Mahvash says:

    Hi Shahriar,
    Your video on Tektronix RSA306 Spectrum Analyzer was very descriptive and helpful. Going into the details of each product and how to use them and show the process in a clean format is great. I am using them as my resources now whenever I want to start working with such new EE equipments.

  61. berna says:

    I am doing my final year project which is microwave filter for spread spectrum and i just want to say thank you for your videos. It is great job!

  62. John Tucker says:

    Shahriar, just wanted to say hello on your blogsite. I linked your Keithley 2450 and 2460 review videos on my ham radio website: http://www.n8mdp.com/videos.php. Thanks again for the great videos.

    John Tucker

    • Sal C. Cornacchia says:

      I review video on Microwave components and fid it very interesting, I have bee in the electronic field most of my professional life, over 50 years always wanted to be an RF and Microwave Engineer, I consider to be a self made Electronic Engineer as I have very extensive practical experience in electronics I owned an electronic test and measurements business and a communication and other Electronic related services until I retired, I am still active in the electronic industry it is very difficult to keep up with technology.

      Sal C. Cornacchia

  63. Vahid says:

    I check your review about Keysight MSO-S Series 10-bit 20 GS/s Oscilloscope .
    I work a lot with RADAR and in some case we need to measure timing circuit (time expansion ). I saw that this scope has one ADC which use for all four chanel . now is coming one big challenge for this scope to make very simple measure but at the same time difficult , this test challenge the trigg function in scope as well .
    here we go :
    1:We have two oscillator which are very close to each other , say square signal with amplitude of three vpp and frequency of 2000000 Hz in channel one and 2000004 Hz with the same amplitude to channel two . these can be made easly with Tek generator
    2: you can trigg on channel one when their edge start at the same time
    3:Use math function or what ever you want on scope , to measure the time difference between each positive flank between these two channel and plote it.
    note that the trigg should be accourde when these two are at the same flank.
    the oscillator that gose faster by 4 Hz (250ms) will run just very tiny amount of time forward compare for each flank compare to one that gose slower .
    when you plote it it should one linear line.
    this methode is use for time expansion in RADAR , We test it with all best scope in market but it should that it is only lecroy can make such trigg and calculation , each time step is arround 10ps .

  64. Steve says:

    It would be really fun to see you do some experiments with those high bandwidth spectrum analyzers where you demonstrate the spectra of sampled signals vs sample rate and then did some Hilbert transforms and instructed on quadrature sampling.

    From your videos I know this kind of thing is trivial to you, but I thought I’d ask – it’s something that is so basic to DSP, but seeing it in action might just be very instructive. Some bandpass sampling (software defined radio?) and demodulation could all be demonstrated.

    Just asking – I absolutely love every video you do. You are a natural teacher.


  65. randlemeebers says:

    Shahriar I thank you so much for your blog.
    In particular I find your medium/advanced engineering blogs the most useful. Please keep the good work up. If you had merchandise I would be a customer of yours.

  66. Russ Ramirez says:

    Shahriar, would you have any interest in doing a repair video on a Maury/Eaton Noise Factor Measurement system? I have one if you are interested, the unit have what seems to be a minor RD leveling issue.


  67. Shahriar says:

    Just wanted to say hi!

  68. Asghar Dabiri says:

    Dear Shahriar;
    How are you ?
    I need schematic for Agilent 4407B .How can I order them? Do you sell them? How much?
    When they will be available free from keysight?

  69. mohammad says:

    Hi my friend
    Your channel is very interesting and so lovely video’s and reviews!
    Can I ask you something? Where are you from?

    • Shahriar says:

      I am Persian born, Canadian citizen living in the USA.

      • mohammad says:

        Wow-OMG! 🙂
        I’m so proud! First time (maybe 2 or 3 years ago) when I saw your channel! Said to myself this guy is so familiar to me! :))
        already my heart had said that you are persian! less than a month ago I saw in comments that somebody called you “Shahriar”!!! you have a great channel and vids-love it
        can you speak in persien? which city you are from? I’m from urmia! 🙂
        vaghean khoshhal shodam- ye chizi az hamun aval to zehnam migoft in iranie hmishe ba khodam kalanjar miraftam ke in pesar cheghadr raftaresh shabihe iranihas!
        az video hat kheili chiza yad gereftam va omidvaram hamchenan edame dashte bashe!
        arezooye movafaghiyat barat daram! 🙂 duste man

  70. Armen says:

    Hi Shahriar,

    Great eval videos!

    Can you please evaluate and test the R&S RTO series scope?


  71. Dave says:

    Great channel. You have a unique manner of explaining: quick (get to the point!) and clear. We like the movie to “move along”! Well done.
    I especially enjoy your repair videos even if they don’t result in a fix (ie, the Agilent display). It’s the troubleshooting that’s valuable to see. Troubleshooting is transferrable to any equipment. That’s what I take away from your videos.

    Keep it going!


    PS, what city do you live in that you can score such dumpster finds as you have? At a university?

  72. Bernhard says:

    Hello Shahriar!
    Thanks for your great videos!
    Which SMA/SMA cables are you using to connect your equipment?
    I have to admit that I am using standard RG58 SMA/SMA cables to do measurements with my 6GHz R&S spectrum analyzer which have been previously checked against my N5182A signal generator (verify actual loss in the cable and adapters at the desired frequency). This works but I would like to spent some money to get real quality certified SMA cables and so I would like to know your recommendation.
    Thank you!
    Best regards,

  73. 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.


  74. 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

  75. Michel says:

    Hi Shariar,

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

  76. 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.

  77. 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.

  78. 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.

  79. 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.

  80. Zucca says:

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

  81. 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.


  82. Petra Gant says:

    Hi Shahriar

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

    Hello from Hungary!

    Petra Gant

  83. 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.

  84. 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!

  85. 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!”

  86. 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.

  87. 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

  88. 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,
    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!

  89. Minna Millet says:

    Audio amplifier is considered as an important element of audio tracks that document the equipment. The audio amplifier is basically designed to get used to play the audio tracks from bands. The amplifier collects all the energy that must be carried out to develop an ideal look. It often consists of circles, with the vitality of the first use of its lines, to increase the collective purpose of using the recent output seems to be initiated immediately to the speakers. ‘

    Visit our personal web page too

  90. 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 🙂

  91. 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! 😉

  92. harold housen says:

    how do I become a member

  93. 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.



    • 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.

  94. Joachim says:

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



    • magic says:

      great suggestion, fourier analysis and FFT, IFFT explanation and experiments too are very welcome.

      thank you for your efforts.

  95. 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

  96. 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.


  97. 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

  98. 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

  99. 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?

  100. 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.



  101. Nemanja says:

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

  102. Tarik says:

    You are great man, please continue your work.

  103. 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.

  104. 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)

  105. 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.

  106. 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.

  107. HarvHam says:

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

  108. 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.

  109. 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?



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