Analog vs. Digital: Whatever Happened to Pure Analog?

At number three on Fortune Magazine's “50 Greatest Business Rivalries of All Time” list is a story of the conflict between Thomas Edison and Nikola Tesla over power distribution techniques; namely DC proposed by Edison and AC proposed by Tesla. We all know how that ended and the story offers some interesting if not gruesome sidebars regarding the effort to which Edison went to discredit Tesla's approach. By the way, Nikola's namesake, the Tesla automobile, which operates from a pack of over a thousand lithium-ion batteries, is actually AC powered, thanks to a bucket full of IGBTs. The Tesla Roadster uses an (AC) Induction motor, first patented by Nikola Tesla in 1888.

The whole AC vs. DC thing got me thinking about analog vs. digital. The Tesla powertrain is a perfect marriage of these two technologies. As I contemplated this, I tried to think if any of the electronics in my life are pure analog (or pure digital, for that matter). I walked through every room in the house and took an inventory.

Fifty years ago, this would have been a no-brainer. My TV, my car radio (AM only), my phonograph player, the heater thermostat, the telephone (anyone remember POTS?), my ham radio… they were all analog.

Today it's a different story. My TV is digital and much improved from the one in my home as a teenager. My car radio is mostly digital. My phonograph and reel-to-reel tape deck — well, I'm not sure what happened to them, but my music is now stored and played back digitally. My ham radio is full of digital stuff that makes it far superior to my old (dare I say it) Heathkits. My telephone has digital everything… memories for my frequently-called numbers (I used to use my brain for that), auto redial, caller ID, yada, yada, yada.

Even my brand new water heater has a digital chip in it. My power tools have digital speed control and laser light guides. Many of the lights in my home now have power management chips in them. My computer is mostly digital but the audio is analog. I tried to identify anything that was still all analog in my life (aside from me, and that of course remains questionable). I found one item; my Collins 30L1 Linear Amplifier (for my ham radio), but hams are an anomaly and cannot be part of any such survey. One thing I know for sure. If one of my old analog products ever broke, I could fix it.

I'd be curious to hear from you if you have any pure analog or pure digital items in your life — that is, of course, if any such items exist.

26 comments on “Analog vs. Digital: Whatever Happened to Pure Analog?

  1. jkvasan
    April 16, 2013


    We had a valve AM radio which was pure analog. Another such device is a blind temperature controller. This means it doesn't have a display. It uses a simple LM324 to linearize a J type thermocouple output and compare it with a scaled analog voltage  from a potentiometer. The comparator output drives a relay through a transistor.

    One more device is a surgical cautery, I saw recently with a refurbished equipment seller. It was manufactured by Cameron-Miller USA.

  2. Bob @ JVD Inc.
    April 16, 2013

    I missed Netcrawl's post…

  3. Bob @ JVD Inc.
    April 16, 2013

    Awesome. I'll bet the sound quality from thoese speakers is pretty decent too.

  4. Vishal Prajapati
    April 17, 2013

    I can recall when I was teen, I used to go with my dad in his office on the weekend. He is in Police Communication Department. They have their own freq band of VHF and UHF for communication. One of the old wireless set was 20 times bigger than available now a days. It had big rotary dials with handle to tune the chennel freq of the wireless set. They looked something like below image but was even bigger. My Dad said, it was purely analog and with valves in stead of transistors and FETs.Wireless set with valves

  5. Netcrawl
    April 17, 2013

    @Vishal that was great thansk fro sharing that! does still working? I think analog is losing the battle here, the whole industry are taking a dramatic shift toward digital, and everything around us goes with it.  

  6. Vishal Prajapati
    April 17, 2013

    @Netcrawl, No it is not working today but it has been put in the Police Department Museaum right now. But it was surprising to see the complexity and accuracy of the circuit design despite lack of morden mix signal chips and fency test instruments.

  7. SunitaT
    April 17, 2013

    I have dad's favorite radio in my home. His day start with Aakashvaani NEWS. Even though we have most of new electronic gadgets in home but he enjoys most while hearing the radio.


  8. SunitaT
    April 17, 2013

    This reminds me of trunk calling during my childhood. Whenever we need to have long distance call, a request needs to be placed to telephone department. When our request is serviced they use to call source and destination in telephone office and connect those two line manually. Now everything works on switches which are operated digitally.

  9. riscy00
    April 17, 2013

    Analog alway remain with us even longer but smarter due to improved digital intrerface and control (user interface). Not all application replace the digital fully.

    The next phase is optical interface  (Google Glass) and bio-interface, brain implant…..who know. 




  10. divide_by_zero
    April 17, 2013

    I have a parts kit to build a pair of Linkwitz Lab Pluto 2.1 amplified speakers. These were designed by Sigfried Linkwitz, of Linkwitz-Riley crossover fame. He worked at the test equipment part of HP before it was spun off as agilent, designing some of their spectrum analyzers and other RF and EMC equipment. The speakers utilize totally analog op amp-based filters for crossovers and equalization. Some of his more upscale designs utilize his generic ASP (analog signal processor) board, which are also op amp-based. We don't need no steenkin' DSP chips here.

  11. Bob @ JVD Inc.
    April 17, 2013

    The history is great, but my challenge was to fine pure analog in your life today.

  12. Bob @ JVD Inc.
    April 17, 2013

    divide_by_zero. Let me know how it performs.

  13. eafpres
    April 17, 2013

    I believe somewhere I still have one of those big, black Simpson meters.  I think that would qualify as pure analog.  I inherited it from my dad.  Nowadays, with all digital autoranging meters, nobody has to think to set the AC scale to max before checking a circuit, to avoid “whacking” the analog meter to full scale.

  14. Bob @ JVD Inc.
    April 17, 2013

    You just reminded me… I too have an old analog meter…an EICO kit I built in 1962. Wow… I need to go did that out…it probably needs a fresh battery by now.  🙂

  15. Brad Albing
    April 17, 2013

    I assume you wrapped the al-foil around the fuse – just to make sure….

  16. Brad Albing
    April 17, 2013

    You're ignoring the wife factor with those speakers – i.e., would you have permission to put two of those in the living room….

  17. Brad Albing
    April 17, 2013

    That would be the Simpson 260. Damn good meter.

  18. Brad Albing
    April 17, 2013

    Um… and probably a new battery holder.

  19. Netcrawl
    April 18, 2013

    @Scott you're doing great on that! trying for new ways- that's creativity. 

  20. amrutah
    April 18, 2013

    @Bob: Tesla powertrain and roadster are awesome systems. How reliable are these vehicles, why are they not popular?

    @Scott: Many Thanks for sharing the video.  That looks hardcore analog system.  Sounds great too… 🙂


  21. Brad Albing
    April 19, 2013

    OK – that works too. I still like my version where you completely wrap the fuse in al-foil and stuff it into the holder/clips. That can help to find the next weakest part of the ckt (or the part that is actually causing the problem). Just another analog design/trouble-shooting technique that the digital guys would never have thought of.

  22. EmmettRedd
    April 22, 2013

    I claim that there are no true DC motors.  Except for the homopolar motor, a coil's current has to flow in both directions.  When it comes to motors switching directions of current flow, DC motors switch internally, AC externally, but both are switching.  Even in the homopolar, current along a path (fixed to the armature) rises above and falls to zero (which we all know is a superposition of AC and DC). 

    I think we can have true DC motors when we discover magnetic monopoles.


  23. Doug Grant
    April 29, 2013

    Wait…did you say ham radio was an anomaly?!? If you have a complete S-line to go with that 30L-1, you have an art collection. Take a look at the Collins PTO if you want to see some analog wizardry in action!

  24. Bob @ JVD Inc.
    April 29, 2013

    I wish I had the S- Line !!!!!  iCOM 775DSP…. Hope to get a new Kenwood TS990S later this year / early next year

  25. Brad Albing
    April 29, 2013

    There is a tendency here to go off on tangents with these discussions. Thanks for working to bring it back on point.

  26. Brad Albing
    April 29, 2013

    Oh yeah – the switching action due to the brushes and the commutator. I guess that is the key to making a motor that can be powered by DC. Rather like thinking of a switching power supply (think push-pull or bridge topology) as if it were a “DC transformer.”

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