On saves, I could do with being able to recall setups quickly for different jobs (outside of creating an externally imported waveform) ..it would save the chore of recreating the synthesised setup each time for complex do dads. Its curious that its missing.
Onto something else from me,
Did some quick and dirty ballpark testing of this unit out of curiosity & heres the results:
UNI-T UTG962 noise floor analysis with Siglent SDS1204X-E scope - Testing different power source influences.Quick Conclusion: Powering the UTG with a (merely average) usb power bank can make a dramatic difference to signal noise levels. Also, the output from the UTG is quite unexpectedly & remarkably clean when given a decent power supply. So much so, its own inherent noise is frequently barely above that of the oscilloscope.
Siglent SDS1204X-E scope Baseline Details:Scope Channel - Unplugged.
- (200MHz BW) 0.12mV RMS - 0.80mV Pk2Pk
- (20MHz BW) 0.10mV RMS - 0.40mV Pk2Pk
Scope Channel - 50 Ohms direct terminated.
- (200MHz BW) 0.12mV RMS - 0.80mV Pk2Pk
- (20MHz BW) 0.13mV RMS - 0.40mV Pk2Pk
Scope Channel - CH3 Terminated into CH4 via scope lead.
- (200MHz BW) 0.14mV RMS - 0.84mV Pk2Pk
- (20MHz BW) 0.13mV RMS - 0.44mV Pk2Pk
Test Scope Setup Conclusions:
* Using a proper 50 Ohms bnc terminator actually slightly raises noise floor.
* 'properly' Terminated Scope lead shows that it introduces negligible noise.
Note: the Ground pin next to the calibration terminal is actually rather unacceptably noisy in the millivolt range.
UNI-T - UTG962 Test Setup Details:* Test of fairly decent generic mains usb PSU and a fairly standard USB battery power bank as power sources.
* UTG connected to scope via supplied bnc to bnc cable.
* Test done by placing the signal generator into DC output mode & taking it thru the entire unipolar voltage range, with scope in AC coupled modes to establish noise levels present.
* Measurements taken at 1mV/Div and at 20ms (a 280ms sampling window).
* 20MHz & 200 MHz modes used to crudely establish extent of unwanted noise density in different ranges.
* Note: some very minor DC shift was observed whilst taking these measurements, I expect this was down to saturation quirks of the scopes AC decoupling stage, this was compensated for with offset.
Results for (non uni-t) reasonable quality mains powered USB adapter:PSU - Channel OFF - Much Lower Noise than channel ON.
- (200Mhz BW) 0.39mV RMS - 2.50mV Pk2Pk
- (20Mhz BW) 0.35mV RMS - 1.20mV Pk2Pk
PSU - 0-560mV - Significant noise floor rise upon switching channel ON.
- (200Mhz BW) 0.41-0.43mV RMS - 8.50-9.00mV Pk2Pk
- (20Mhz BW) 0.37-0.40mV RMS - 5.80-6.50mV Pk2Pk
PSU - 561mV-10V - Slight to moderate rise in RMS noise floor.
- (200Mhz BW) 0.45-1.25mV RMS - 9.00-9.00mV Pk2Pk
- (20Mhz BW) 0.40-0.85mV RMS - 6.50-6.50mV Pk2Pk
PSU - Unplugged - Slightly less noisy across the board than Channel OFF, worst at full bandwidth.
- (200Mhz BW) 0.35mV RMS - 1.10mV Pk2Pk
- (20Mhz BW) 0.33mV RMS - 0.68mV Pk2Pk
Results for iMuto USB Battery Power Bank:USB - Channel OFF - Slightly lower noise than with Mains PSU, particularly below 20MHz.
- (200Mhz BW) 0.31mV RMS - 2.00mV Pk2Pk
- (20Mhz BW) 0.29mV RMS - 0.80mV Pk2Pk
USB - 0-560mV - MUCH lower noise than PSU, though mainly in Peak to Peak noise.
- (200Mhz BW) 0.35-0.40mV RMS - 2.20-2.20mV Pk2Pk
- (20Mhz BW) 0.32-0.39mV RMS - 1.00-1.00mV Pk2Pk
USB - 561mV-10V - MUCH lower noise than PSU, though mainly in Peak to Peak noise.
- (200Mhz BW) 0.37-1.00mV RMS - 3.50-3.75mV Pk2Pk
- (20Mhz BW) 0.35-0.75mV RMS - 1.20-1.20mV Pk2Pk
USB - Unplugged - Same as previously (because of course
- (200Mhz BW) 0.35mV RMS - 1.10mV Pk2Pk
- (20Mhz BW) 0.33mV RMS - 0.68mV Pk2Pk
See middle section of below graph for just how much noise is reduced with a good power source, particularly when dealing with spurious, peaky noise.
Some of the screen grabs off the scope, Bottom trace is an unloaded channel shown for scale concerning noise levels.
PSU - Measured at 200MHZ bandwidth:State - Channel OFF, Generator plugged in:State - Channel ON, 0 Volts DC selected:State - Channel ON, 10 Volts DC selected:USB - Measured at 200MHZ bandwidth:State - Channel OFF, Generator plugged in:State - Channel ON, 0 Volts DC selected:State - Channel ON, 10 Volts DC selected:Bonus Bits - PSU and USB at 20MHz Bandwidth Limit:USB - State - Channel ON, 0 Volts DC selected:yum.
PSU - State - Channel ON, 0 Volts DC selected:yuck.
Also, yeah ...wow, modern scopes
, and cheap ones too having sub millivolt noise on their front ends (0.10-0.80mV), at hundreds of Mhz ..that still blows my mind; and to think I thought the noise floor performance of my old, late 80's analog 150MHz Tek 2445a was pretty decent ..not by half, that had fuzz in the several millivolt range iirc.