Tektronix DSA602 Harmonic Distortion Measurement ?

[Johnny10]

I am trying to determine if the DSA 602 is different from the DSA 602A.
In the DSA 602A manual it shows a measurement window that allows for selection of Spectral Frequency, Spectral Magnitude & THD.
On my 602 I find no such window.

I have continued checking different manuals on this and I guess the 602 does not have the added features outlined in the DSA602A Manual.

[edavid]

I am trying to determine if the DSA 602 is different from the DSA 602A.
In the DSA 602A manual it shows a measurement window that allows for selection of Spectral Frequency, Spectral Magnitude & THD.
On my 602 I find no such window.

The main hardware difference is that the DSA602A has the floppy drive, but of course DSA602As have later firmware as well.  So maybe you could upgrade your DSA602 EPROMs to get that function.

(Of course a DSA602 is never going to be a very good THD analyzer, due to digitizer limitations.)

[Johnny10]

Could you explain the THD digitizer limitations.
I have available in my area a broken DSA602A that I might be able to use as a parts unit for low dollars.


Of  course I realize this FFT only good to -60 to -70dB
Data sheet from DSA 602A
Measurement System

    Amplitude: Min, max, mid, mean, p-p, gain, RMS, overshoot, undershoot, area +, area -, and energy.
    Timing: Rise, fall, width, delay, main-to-window trigger time, period, propagation delay, cross, phase, frequency, duty cycle, and skew.
    FFT: Fundamental track, harmonic amplitude, frequency, and total harmonic distortion.
    Statistics: Available for any measurement listed above for both live acquisitions and groups of stored waveforms.
    Cursors: Single or dual dots, split or paired mode, horizontal and vertical bars, and measurement-zone delimiters. Delta volts, delta time, 1/delta time, and slope.

 Waveform Processing

    Waveform Functions: Absolute value, average (exponential and summation), convolution, correlation, delay, dejitter, differentiate, envelope, exponential, FFT filter, FFT integrate, interpolate, log, natural log, pulse, signum, smooth, and square root. Live waveforms can be changed by using adjustable parameters.
    Arithmetic Operators: Add, subtract, multiply and divide.
    FFT: Magnitude and phase; real and imaginary; inverse FFT, correlation, and convolution; six window functions; Typical Noise Floor: -60 dB; -70 dB with averaging.
    Act on Delta: Save, repeat, chime, SRQ, and hardcopy.
    Histograms: Vertical or horizontal histograms generated from a user-defined portion of any waveform. Statistical information is provided for histogram data.

[edavid]

Could you explain the THD digitizer limitations.

Just that you only get 32K points at 8 bits.

[Johnny10]

I found a Service manual for DSA600 series that talks about certain features only available after Firmware 2.0.

Mine is older 1.3 version