In addition, R should be changed to 1k 2. If the triggering on negative slopes doesn’t stabilize at elevated board temperatures, decrease R On the other hand, the correction is applied to data reloaded from disk even though saved data are already transformed; reloaded data are therefore expanded relative to the markings! War and Popular Culture: Replace C22 by a 0-Ohm connection.
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The trigger, however, is accepted only before every other sample, causing a time jitter of two sampling intervals! The expansion appears to be uniform, and the transformation therefore linear. I suspect the unreasonably high current through the LM, the choice of a resistance ratio corresponding to a rather high target voltage, and the extra OpAmp buffer are all the result of an abortive attempt to raise VRT to an acceptable level.
Hung Chang DSO – [DOC Document]
Post on Dec 26 views. There is no value of R that guarantees stable triggering on both positive and negative signal slopes at all board temperatures. Without R-C damping of this order the digital noise seen at high sampling rates up to about 0. Rapid negative signal transitions as exhibited by the calibration signal measured with a probe are therefore regularly after about ns delay followed by false positive ones whence triggering on positive slopes becomes bistable.
And don’t ask me for support on this! Amplifier Linearity, Rise Time, and Thermal Drift The DSO amplifiers have the usual high-impedance FET input stage a cascode of two 2SKs, where the top FET operates as a source follower and the bottom FET as a constant-current active load followed by a HFA current-feedback amplifier gain block followed by a discrete differential stage where the screen offset is added three 2N jelly beans, with some massaging of the frequency response followed by a PNP level shifter 2N and another HFA gain block unfortunately, the built-in clipping function of the HFAs is not used.
Without R-C damping of this order the digital noise seen at high sampling rates up to about 0. Most unbelievably, of the spectral points only are actually displayed, the 21st, 64th, and th are skipped and the th is omitted! Briefly unplug the power supply of the DSO unit to recover from this. EXE at hex file offset from hex 20 to hex 03 and at hex file offset c6 from hex 10 to hex 03 to see this.
Replace C22 by a 0-Ohm connection.
Hung Chang DSO 2100
I have moved the free 1. Here, the spectral points are numbered from zero. Although one of the DAC channels used for calibration is reserved for a variable trigger level, on my board some components necessary for this option are left out, and the Hung-Chang operating software makes no provision for setting this channel.
Along the way I dsp2100 that the DSO differs in important respects from the specifications stated in the chqng brochure and until on the Hung-Chang website, and also until by Conrad Electronic, a German electronics chain store where the instrument was on sale.
Oscilloscopio 60 MHz – test-italy.
Hung Chang DSO
Needless to say, the responsibility for any action regarding your DSO is yours! The National datasheet specifies an absolute maximum rating of only 15mA! The sparkle is easily seen when a suitable signal is heavily “undersampled”, but remains cbang in ordinary work.
Make absolutely sure your signal is free of high-frequency hidden spikes when looking into trigger stability!
The linearity of the DSO amplifiers is good, but the gain of the differential stage depends on the voltage level at its inverting input, which is controlled by the corresponding vertical offset knob. Some resistors and capacitors in the amplifiers are?
It’s a shame the unit was marketed at this immature stage. Dso200 you have studied the description you will probably concur that the DSO hardware was insufficiently debugged, and not ready for sale. Once you have studied the description you will probably concur that the DSO hardware was insufficiently debugged, and not ready for sale.
Needless to say, the responsibility for any action regarding your DSO is yours! As I see it, this resistor in the positive supply line of the trigger comparator utilizes the switching current spike boosted by C and C78 at output pin 9 to suppress spurious oscillations about 25MHz during the chnag transitions at output pin I cgang also replaced C96 by a 22? The gain calibration probably cannot absorb a change of VRT from 3.
A friendly correspondent, Anton Zechner, from Austria has contributed an upgrade utility http: More disturbingly, the distinction between positive and negative signal slopes is unsatisfactory even for the simple 1kHz calibration signal; it looks like the trigger comparator U26 LM suffers from internal ringing, as the unit often triggers on negative edges when set for positive ones, and vice versa.
Some resistors and capacitors in the amplifiers are? If the triggering on negative slopes doesn’t stabilize at elevated board temperatures, decrease R