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  • EEVblog #575 – DIY 1970s Spectrum Analyser

    Posted on January 31st, 2014 EEVblog 13 comments


    Phil VK2BDF from the Manly Warringah HAM Radio Society shows off his 1970’s vintage home made 200MHz DIY spectrum analyser.
    Forum: http://www.eevblog.com/forum/blog/eevblog-575-diy-1970s-spectrum-analyser/

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    • http://www.mwrs.org.au carlo

      Great Vid.. Thanks for visiting us on Wednesday!

      • Geoff

        +1

        Thanks for visiting, Dave! Great vid, the VHF cavities Phil tuned up with that analyser are still in active use today some 30 years later.

    • Dave B.

      Thanks you very much Bill and Dave. Very enjoyable. That spectrum analyser would have been like gold in its day… wonderful!!!!

      It highlights that one reason people often designed and built their own gear was cost savings. You saved a bundle home brewing audio amps, radio transmitters, antennas, power supplies. The huge bonus was you KNEW how the device worked. There was always a massive sense of satisfaction and accomplishment when you got it working. Never thrown out.

      These days equipment and consumer stuff is far too cheap and home brew is almost dead. The nearest the Big Brother generation get to home brew is watching stupid cooking shows on TV. Most Engineering graduates today have never hard of ham radio and most would not know how a $5 AM radio worked – and nor are they interested in finding out. There are a few exceptions though, but they are few and far between.

      My biggest (literally) home brew was a rotatable 8-element log periodic dipole array erected atop a 60 foot tower. The biggest element was 36 feet and the boom length was 33 feet. It was beautiful. The SWR was below 1.5 from about 13 MHz to 29 MHz. I built that antenna on 5 acres in country Victoria at a time when I did not even need council permission to erect it. Today, councils interfere with your freedom and charge you for doing so. That antenna gave me the world.

    • phenol

      wonderful. It’s full of those gold-plated color-coded TO-92 transistors from the 70s, just like my 1976 HP scope.

    • huh

      Thanks Dave and Phil!

      This was fascinating. Albeit I’m an IT guy, no digital instrument can match the beauty and ingenuity of those tools built by knowledgeable techies with what they had available at the time.
      More of that, please.

    • RogerS

      Video blog 575 – Great episode Dave! Looking over the home brew spectrum analyzer from the 1970’s! No SPICE, No CAD, Few ICs, limited capability electronic slide rule calculators (he probably did the math with a real slide rule!) Carbon comp resistors, transistors and a few op amps. Old school electronics at its best! Kudos! Would like to see more of these interviews with men and women that aren’t afraid to bootstrap what they need to do the job.

    • Mike

      That’s just a magnificent analyser and a wonderful man! Thanks to Dave and Phil!

    • PK

      What a great home-brew project! Wonderful to see what can be built with limited resources.

    • Paul

      You really should invited Phil to the Lab he must have lots of wonderful stories to tell, in fact I think you should adopt him.

    • http://electronics.stackexchange.com/users/930/zebonaut zebonaut

      Wonderful. A piece of beauty.

    • DL8LAQ

      Hi Dave,

      thanks Bill and Dave for showing us this beautiful home brew spectrum analyzer. Well done, Bill!

      73, Norbert

    • http://www.qrp.gr sv3ora

      Hi, ho ccould I contact Phil VK2BDF ?
      Is there an email or website of his?
      Thanks

    • http://www.worldwidedx.com Robb

      Dave Jones:

      Like to see you build a spectrum analyzer using software defined radio.

      This Phil chap did a fine job.

      Many of us radio operators on the worldwidedx.com watch your videos – great stuff. Always interesting and informative!

      73