Using the attached table with device models, a 5444B is listed 4 places "higher" than the 5442B. So I incremented "1C" => "20" for byte "0B"
Hello,
do you now have 512 MS memory and 48 kS buffer space for AWG and really 200 MHz bandwidth?
ETS mode is 20GS/s
Best regards
egonotto
Hello,
do you now have 512 MS memory and 48 kS buffer space for AWG and really 200 MHz bandwidth?
ETS mode is 20GS/s
Best regards
egonotto
Nice!
Dave did a teardown of this scope a few years back, but didn't open up the front end cans.
youtu.be/TM7HGFOc74M?t=351
There is a checksum, but is very weak and overly complicated. The last two bytes contain the number of iterations that have to be done to a 14 bit LFSR to get a value that equals the sum of the preceding data when interpreted as signed bytes. The weakness comes from their method of reducing the sum to 14 bits: During summing they reset the intermediate value to zero as soon as it uses more than 14 bits. As the bytes added are signed, this happens very often.
Did you try figuring out the checksum algorithm at all?
Not sure how they worked that out.
Don't think I've never seen LFSR used as a checksum method...ahh, well I suppose crc is an LFSR method.
in PicoScope the entire memory is specified in bytes. Only in single trigger mode you can use it. Otherwise you only get half the memory because of double buffers. In 12 bit mode, a sample is 16 bit, so you have fewer samples.
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The band width of my PicoScope 100MHz 5234A is greater than the band width of the PicoScope 200MHz 5444B
Hi Egonotto, another question, do you also see spurs @multiples of 62.5Mhz in FFT mode (8-bit mode) in your 5444bB? This are most probably coming the interleaved sampling of the hmcad1520 ADC. In 12-bit mode these appear every 31.25MHz.
My 5444B and 5234A also have spikes.
One more hardware difference between the low end model and the high ends models: a different clock is used. Not sure though if this is worthwhile to try and upgrade.
just to give you an idea of the huge cost gap between the low end / high end series BOMs ...
+/- 50ppm : low cost oscillator, price under 1 euro in quantity of 100
+/-2ppm : TCXO, unitary price around 2 euro in quantity of 100
In your place, provided that your warranty is dead, I would proceed with the mod.
just to give you an idea of the huge cost gap between the low end / high end series BOMs ...
+/- 50ppm : low cost oscillator, price under 1 euro in quantity of 100
+/-2ppm : TCXO, unitary price around 2 euro in quantity of 100
In your place, provided that your warranty is dead, I would proceed with the mod.
It is not the cost that would make it worthwhile or not, it is the trouble to find out all of the correct surrounding component values. Also the risk that if they are not correct, I make it worse instead of better. And the fact that the upgrade it will not make a whole lot of difference in my opinion. If I had a schematic of the 5444B, I would for sure do it however, as then it is easy and risk free.
For example, the resistor I have changed above to increase the bandwidth, could still have other negative effects I am not aware of and was not the only thing (or not even the thing at all) that needs to be changed to increase the bandwidth. The more I think about it, the more I think those 75 ohm resistors should remain in place, and some other component(s) needs to be updated/removed to increase the bandwidth of the front end. But without schematics and without even a picture of a 5444B front end, that is hard to evaluate without a complete reverse engineering to the front end.