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Recent content by VisiGoth

  1. VisiGoth

    "Interpolating" to estimate exact frequency of peak from FFT results

    All very interesting. But the "best" answer is really quite simple. The FFT is providing maximal compaction of data already. Do not zero pad. Do not window. Those techniques are for their own purpose. If you do neither you can use a zero bias answer that is also lowest variance. Simply...
  2. VisiGoth

    LNA Predistorsion

    Are you saying that you can count on the distortion caused by the diode will be undone by the LNA first transistor? This sounds like a schoole problem, not something an engineer would do. Or am I out of touch with the state of the art in high linearity LNA's? I have hear of using the same...
  3. VisiGoth

    Kuwahara filter help

    This question is about the varioable "original", not about the function. Can you post information about your variable. Did you really mean the string variable 'original.tif' or something like that?
  4. VisiGoth

    Typical Relocation Compensation

    Wow, this is a real eye opener. I thought $2k was top dollar. And if you were a real sharp shooter you could get a $10k bonus without any pretense about using it for moving. I must be in the minor leagues.
  5. VisiGoth

    Weather telemetry? (remote station data logging)

    lease cell phone telemetry modems. Build your own folded dipole by looking at a ham radio book. This may be the lowest cost reliable method.
  6. VisiGoth

    Measuring Distance via Radio Waves

    You may be thinking about toy GPS like the ones built for cars that need nearly line of sight. The higher sensitivity used in cell phones can probably receive as well as you think you can do at your own frequency. Contact the telematics group at the major cell phone companies. They...
  7. VisiGoth

    Different results using SS and TF forms

    It is a coding standard problem. You did not return the results of thebuilt in function, the the reviewer and maintenance people can not determine correct behaviour at a glance. Try doint it in two steps, the ss2tf returns b before a. [b,a] = ss2tf(A,B,C,D,iu) jsolar
  8. VisiGoth

    high current JFETs

    The resistor is the simplest solution. And you can't get more reliable at only 10W. But you do not need an inductor based on your charging time constant. You can create an intermediate time constant based on a clock. i.e. 100 kHz switcher current source would be a small low cost solution...
  9. VisiGoth

    Measuring Distance via Radio Waves

    If you still want to create your own system and you can afford the cost of free spectrum then do the math. SNR and BW determine distance variance per the CRB. Search those terms or find them in the books. You need bandwidth to overcome noise. You will find that the open spectrum using the...
  10. VisiGoth

    high current JFETs

    logbook has a good point. With global warming and all a switching power supply may be a good idea. Your inductor should not be designed based on the time constant of the charge time but rather on the time constant of your switching time, which is anything you want. You might find an itty...
  11. VisiGoth

    solving ode without using ode solver

    The very name rk45 is because that method itself uses two different methods and compares them internally to determine a sense of the accuracy. You can write you own method that does not replace all of the very difficult MATLAB functionality if you only want to test accuracy. Go ahead an write...
  12. VisiGoth

    Spectrum analyzer measurement

    The analyzer may be giving you power density readings. If you are not putting in a power density but rather a power at a specific frequency you want to convert the power density of your reading into an absolute power by integrating over the instruments bandwidth. The manual should explain what...
  13. VisiGoth

    Isolated Offline flyback with no auxiliary coil

    Flybacks are for dirt cheap volume. Flybacks that power the back circuit are even cheaper. They are for very high volume experts that can trade NRE for RE. If you are going to put in a power module you probably could have had a safer easier to design to start with, or just buy modules if this...
  14. VisiGoth

    digital integration

    I do not think your problem is in your integration routine. But you can publish your routine or test it with synthetic data. I will think you will find the sticky reality issues with accelerometers and displacement estimation a difficult problem. I have studied Jack Crenshaw's book and have...
  15. VisiGoth

    FFT in MATLAB

    See cibrichrome (spelling) thread575-194153
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