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Practical Analyzer series

Discussion in 'Electronic Design' started by Jamie, Feb 23, 2013.

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  1. Jamie

    Jamie Guest

    For reaching the farther end at a budget
    one can swing, I think this series is more suited.

    You simply need to supply a PC/Laptop, which isn't a
    big deal these days.


    I have absolutely no affiliation with this company..:)

  2. Joerg

    Joerg Guest

    I'll second that. Most of all, the track gen looks a lot more clean than
    what Dave Jones showed for the TG of the Rigol. What I like most is that
    it's all so small, I can easily carry that plus enough clothing and
    stuff for 3-4 days in a pilot's case. But one has to keep in mind that
    this is a fairly bare-bones SDR, so things like image rejection are done
    mathematically, meaning it can fool you with pulsed signals.
  3. Joerg

    Joerg Guest

    Nah. I do this on a Gammatech Durabook laptop that is around five years
    old. Runs like a champ. It was a bit advanced for its time back then and
    contains a very sporty AMD processor.

    On the road I used the Signalhound with a Samsung NC-10 which has a li'l
    Atom processor. That is more like trying to pull a horse trailer with a
    Toyota Hilux but when backing off on the display mode it was no problem
    at all. Did a whole big pre-compliance job that way. The plots I got
    were rather close to what the client later got at the EMC lab (and passed).
  4. Jamie

    Jamie Guest

    Most of my PC's and laptops are high end stuff. THe older slower
    items I use for hooking up to micro controllers for programming etc.

    Most systems these days will render a basic image just fine. I think
    you'll find that games have a lot more cpu intense processing going on
    out side of rendering that slows things down a bit.

    Anything coming through the USB port is not going to be real time but
    close enough for GOV work.

  5. Joerg

    Joerg Guest

    I would not count on that:
  6. Joerg

    Joerg Guest

    So can you get a true resolution bandwidth of less than 1Hz? How about
    track gen measurements to characterize a narrow crystal filter?

  7. I just did some Conducted Line Noise tests with the Signal Hound.
    While not an EMC Quasipeak reciever, it proved to be worth the effort
    to set it up. The ballpark results were not far from the actual lab
    measurements. And thats even after we rolled our own LISN.

  8. Jamie

    Jamie Guest

    and he will until the dollar is just kinlin wood.

  9. Joerg

    Joerg Guest

    AFAIK that is a major challenge with these cheap sticks. On my last trip
    to Europe I was almost tempted to buy one because it's smaller than the
    Signalhound. But when I saw the result from others I refrained. Dynamic
    range and intermodulation range were also issues.

    So your software solders together a complete TG? Wow! But before I
    believe that I'd like to see it.

    If you have no clue about digital signal
    I know signal processing.

    Yeah, for hobby those can be nice. Give you a tool that wasn't on the
    shelf before, for little money.

    Oh, I won't :)

    IMHO he has no fiscal discipline whatsoever :-(
  10. Joerg

    Joerg Guest

    Building a small LISN for it is on my to do list since I get involved in
    this more and more. I don't want to schlepp a big one because now most
    airlines over here charge even for the first check piece of luggage.

    But you know how it is with to-do lists. There's higher priority items
    that SWMBO put on there. A "minor" bathroom remodel, some plumbing, ...
  11. Joerg

    Joerg Guest

    Huh? You cannot make a TG with software.
    And how exactly does that create a TG?
    If the prices for using LTE arrive at a reasonable level I might bite as
    well. Or if I need it for the job some day, then I'll just have to.
    Sure, but that wrecks a country. And it seems the majoprity of people no
    longer understand that.
  12. Joerg

    Joerg Guest

    A tracking generator, so you can do passband measurements, frequency
    responses, and so on.

    I know, that's how the election was won. I believe the increase in food
    stamp recipients just during his first four years was around 14 million.
    The increase. Since babies can't apply that probably represents around
    10% of American families. What a dismal record.
  13. Joerg

    Joerg Guest

    Yikes! That's horrid. This is how a good phase noise spec looks like:

    Quote "On prototypes built for 1136 MHz and 1278 MHz, phase noise at
    1KHz offset is -90 dBc and -85 dBc respectively". That's quite a few
    orders of magnitude compared to your TV stick.

    Yeah, that I could not use this thing for my work :)

    But as I said, for hobby or playing around it's probably quite good,
    considering the price tag.
  14. Joerg

    Joerg Guest

    It's far more than 15% because typically only one parent can file yet
    the whole family is on the dole. We can see an even worse trend at our
    church. The number of people lining up for our food closet has AFAIR
    more than doubled. These are folks from outside our congregation, people
    from the wider community. Many were middle class until a few years ago.
    So we regularly ask congregation members to pitch in more. Which is
    never a problem and so far our church always came through, but this does
    not bode well for our country.
  15. Joerg

    Joerg Guest

    More like 80dB lower :)
  16. Nico Coesel

    Nico Coesel Guest

    An RF generator with a stepped sweep is just as usefull.
    Maybe, but the economy went down the drain as well. So it is only
    logical more people are in need.
  17. For tracking applications the only important things are how narrow
    your IF filter is and how quickly you want the plot. At least when
    measuring stable, linear networks, source PN is not critical.

    In fact, spectrum analyzer users who have a max-hold button but no
    tracking generator sometimes use sweep generators or even noise diodes
    as the 'tracking' source. It's painfully slow -- brutally slow if you
    want 1 Hz resolution -- but it can be done.
    Phase noise is normally treated as stationary for measurement
    purposes, for just that reason. The problem with high LO phase noise
    in an instrument like the Signal Hound lies in applications that have
    to run in real time. You can let your phase noise analyzer or your
    network analyzer run all night if necessary, not so much your QAM

    Still, the cheap LO synth chips are getting pretty good. The Signal
    Hound uses the ADF4350 IIRC, which is similar if not identical to what
    Tek uses in their gold-plated MDO4000 scopes. You can buy much worse
    spectrum analyzers than the Signal Hound, and spend a lot more money
    in the process.

    -- john, KE5FX
  18. My guess is YTOs are dead within 5 years. The integrated VCOs are
    just getting too good.

    Two things worth keeping in mind: 1) The mass-market Elonics chip is
    likely quite a bit noisier than the $10 part used in the Signal Hound
    (and MDO4000); and 2) a direct-conversion SDR with a baseband IF has
    an LO noise advantage over a traditional YIG-based spectrum analyzer
    that has to run its first LO at 2+ GHz when measuring at HF.

    The noise advantage is significant for HF/VHF measurement but of
    course becomes less of a factor in the microwave range.
    Actually the Elonics data is using a less-common metric for integrated
    jitter in that data sheet, namely SSB carrier/noise ratio as would be
    seen through a filter of the specified width. Usually you see the
    equivalent figures in ps or fs, and with different limits of
    integration (12 kHz - 20 MHz being common in telecom.)

    The HP 8568A/B is quieter, but its comparable figure is probably more
    like -55 dBc (not dBc/Hz!):

    I didn't have a plot out to 8 MHz handy, but mine shows -59.5 dBc
    between 1 kHz and 1 MHz. Most of the 8568's noise is going to be in
    the sub-100 kHz area anyway, so I wouldn't expect the 1 kHz-8 MHz
    performance to be very different.

    For measurement of HF / VHF sources, the Signal Hound and HP 8568 will
    have fairly similar broadband PN floors. The flicker region, I'm not
    sure about.

    -- john, KE5FX
  19. Joerg

    Joerg Guest

    That gets old really fast when you have to do wide sweeps at a few Hertz

    Much of this was clearly avoidable. Some of the new laws were plain
    stupid. For example, the new medical device tax has killed tons of jobs
    out here. Predictably so. That's just one example out of many. It will
    have much more far-reaching consequences then most people see.
  20. Guest

    The economy is being held back *intentionally*. People are in *want*.
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