Common mode noise can intrude rails. Oscillation is not random, its periodic as created by self instability. Looks like a crooked sine or a bad triangle. A scope triggers on it and you won't miss if it ever appears riding on the rails of your equipment.
Short ground needle accessory on naked nose probe helps picking less interference than with probe's neck ground return crock wire. Due to much less inductance and narrow loop area very near to nose pin.Ground pollution it was Yoda says. Disappeared with 200 kHz bandwith limiter. Probe on negative rail
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Yes I get quite different results on my kitchen table just by placing things different. I need to get my little lab bench in order, but it is serving as some kind of junkyard storage right now
It is double isolated with grounded metal. It makes quite a difference. Also only uses led lights with transformers on a distance etc.
I was perplexed when I saw the line changing quite a bit in thickness for example weather I had the ac plug in the tx box plugged or not, even with the switch off. So line or neutral, not both was in connection with tx primary, that was the only thing.
Projects pile up… well as long as it is fun
It is double isolated with grounded metal. It makes quite a difference. Also only uses led lights with transformers on a distance etc.
I was perplexed when I saw the line changing quite a bit in thickness for example weather I had the ac plug in the tx box plugged or not, even with the switch off. So line or neutral, not both was in connection with tx primary, that was the only thing.
Projects pile up… well as long as it is fun
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I have tried making those with mixed results long ago, they never comes with the probes I have acquired so farShort ground needle accessory on naked nose probe helps picking less interference than with probe's neck ground return crock wire. Due to much less inductance and narrow loop area very near to nose pin.
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Noise enters a loop from everywhere including protective earth. A clever check you did was DUT off. If the noise is still there its from the test set up. Also easy is to flip the Schuko exchanging live and neutral and see if noise changes.I was perplexed when I saw the line changing quite a bit in thickness for example weather I had the ac plug in the tx box plugged or not, even with the switch off. So line or neutral, not both was in connection with tx primary, that was the only thing.
Was in cheapo probes bags along with color rings. Maybe when they were included with economic scopes though.I have tried making those with mixed results long ago, they never comes with the probes I have acquired so far
It is very convenient to work with, decent auto setup to quickly find results and just to take the laptop and scope to where you are also makes it slick. Plus the good generator as you say. As long as there is no high voltage or many MHz or GHz oscillations to look for it does the job very well. I have bigger ones as well but this is used 9 out of 10 times. Handy for online discussions also. Just save to png, no shaky photos of phosfor screens etc
IWATSU JapanLooks ok. Came with some old probe (manual in background). Now sits on some 300 MHz China thingie
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So I’ve been doing some copper lining for RFI blocking. I have not done last wall yet, still thinking of what contacts I will use. I dont like RCA, thinking of 4 pole XLR for stereo signal instead. More of that in future post I think.
I also had to move the grounding plug to make room. It is always connected to the copper lining but I can choose if I want to reference audio ground to earthground or leave audio ground floating, getting it from another device. The unbal to bal converter has rca sleeves and xlr pin 1 always tied to earthground so I can probably take reference from there.
I used the Agilent Probe with its little hook today to test the rails. I tested with or without audioground to earthground, laptop on batteries or plugged, with or without bandwith limit. It made no visible or measurable difference. Rails steady on low millivolt ripple levels.
Then I hooked up the gen to xover in and put some probes on LP and HP. Here is a shot of LP@300Hz
And here is an overlay of LP and HP @ 1037 Hz which is the xover frequency. The almost non existing phase shift is the xovers way of thanking me for granually matching its resistors and capacitors.
Well, onwards to contacting and maybe some listening…
I also had to move the grounding plug to make room. It is always connected to the copper lining but I can choose if I want to reference audio ground to earthground or leave audio ground floating, getting it from another device. The unbal to bal converter has rca sleeves and xlr pin 1 always tied to earthground so I can probably take reference from there.
I used the Agilent Probe with its little hook today to test the rails. I tested with or without audioground to earthground, laptop on batteries or plugged, with or without bandwith limit. It made no visible or measurable difference. Rails steady on low millivolt ripple levels.
Then I hooked up the gen to xover in and put some probes on LP and HP. Here is a shot of LP@300Hz
And here is an overlay of LP and HP @ 1037 Hz which is the xover frequency. The almost non existing phase shift is the xovers way of thanking me for granually matching its resistors and capacitors.
Well, onwards to contacting and maybe some listening…
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