| Products > Test Equipment |
| Pocket-Sized 6 GHz 1 TS/s ET Scope |
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| joeqsmith:
--- Quote from: SJL-Instruments on February 07, 2024, 01:24:33 am ---We generally try to keep all the specs conservative :). ... Perhaps this is a bad idea from a marketing perspective. But much better to underpromise than overpromise. --- End quote --- The rise time on this particular scope puts it closer to 10 than 6G. Trigger sensitivity below 10mV (assuming you provided access). I would say your use of the the word "conservative" is an understatement! |
| joeqsmith:
--- Quote from: SJL-Instruments on February 07, 2024, 12:53:34 am ---... this might be metastability in the trigger circuit. --- End quote --- Is it possible this could have been the cause of my locking up the sweeps? If so, is there actually a way the restarting the software can somehow shake it loose? I could believe when it hung both times, I was working with very low trigger levels. |
| SJL-Instruments:
--- Quote from: joeqsmith on February 07, 2024, 01:41:58 am --- --- Quote from: SJL-Instruments on February 07, 2024, 12:53:34 am ---... this might be metastability in the trigger circuit. --- End quote --- Is it possible this could have been the cause of my locking up the sweeps? If so, is there actually a way the restarting the software can somehow shake it loose? I could believe when it hung both times, I was working with very low trigger levels. --- End quote --- Interesting possibility - we'll do some tests. If the scope is hung or unresponsive, there is a 10 second timeout after which the query is retried. Do you remember if the software hung for more than 10 seconds? --- Quote from: joeqsmith on February 07, 2024, 01:18:12 am ---Now that I have had a small taste, I want these settings exposed in your software! Time to add a power user mode and let us push the hardware! *** --- Quote ---The recommended 200 mVpp is a "safe" guideline. --- End quote --- I don't want to play it safe! :-DD --- End quote --- Along these lines, you can push the timebase down to 8 or 9 ns if you need it. There will be more distortion on Channel 1, but the other channels should be ok. |
| joeqsmith:
--- Quote from: SJL-Instruments on February 07, 2024, 02:32:53 am ---Do you remember if the software hung for more than 10 seconds? --- End quote --- Sorry, I can't say with certainty. If it ever locks like this again, I will take a screen shot and collect some other metrics for you. It's rare and I have no idea how to replicate it. I am certain that the last time I was bringing up the signals amplitude slowly at the time it hung. I was waiting for it to change to Run and noticed nothing was being shown like I normally see with Wait. I zoomed way out vertically and still did not see a trace. Restarted the software and everything started working normally. --- Quote from: joeqsmith on February 07, 2024, 01:18:12 am ---Along these lines, you can push the timebase down to 8 or 9 ns if you need it. There will be more distortion on Channel 1, but the other channels should be ok. --- End quote --- I read this and I thought, surely he isn't suggesting that the start of collection can be set lower than 11, potentially leading to shorter length, lower loss.... A quick test and sure enough, channel 1 about 7.5ns! If using the scope this way, I really don't care about channel 1 distortion anyway. I just need the trigger to be stable. Add all the disclaimers you want to the manual. IMO, specifying the minimums and typical numbers is good enough. But it's a shame to have the hardware crippled by software. If you add support, the first thing I'm going to do is shave off 3ns of cable.... :-+ Still plenty of margin. |
| joeqsmith:
Shown with channel1 boundary set to +/-50mV, 7.5ns start of collection, 1ns sweep range, 1ps resolution. Test signal at 7GHz. THD is around -22dB, down in the muck. I am curious on the cause of the DC shift? The test signal is CW, so I expect something in your front end is doing some rectification that is somehow tied to the trigger. Granted, I know I am pushing this thing to look at VERY small signals at much higher frequencies than you spec it to and pushing that start of collection way early. To be clear, by no means am I suggesting this is a problem. I just want to understand what is going on internally. |
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