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Microcontrollers & FPGAs / Practical guides to BCH FEC?
« Last post by hamster_nz on Today at 06:19:59 pm »
Does anybody have any knowledge or links to practical guides to error correction using BCH codes?

I am comfortable with generating them (they are much like CRCs) but it is the correction side I am interested in.

As far as I understand you try to verify them, much the same as a CRC, and the remainder indicates what errors (if any) exist.

Do I just need to make a lookup table mapping remainder to flipped bits, or does a far more subtle or efficient method exist for correcting the errors?



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Test Equipment / Re: 121GW App Testing
« Last post by Seppy on Today at 06:17:15 pm »
Build 1.6:
- DC, AC, AC + DC Icon glitch resolved
- Icons added to tabs for improved user experience
- Improve scaling of tab titles
- Diode mode Voltage now displays correctly when range is pressed
- M and k now show when the ohms range is over-range

Android App also synchronized, and updated.
The update is pending a package update for the windows App but the Windows App has also been synchronized with all the changes.
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Grinds my gears when people use the word “shall”.
As in “you shall not do this”.
Sounds like they are looking down their nose at you.
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I’ve been using the LT6106 for most of my current measuring; it works great and is super easy to use! If you need more accuracy you can use the LTC6102 it needs a few more components but is more accurate.

Highly recommend these!
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Test Equipment / Re: Lecroy options -=recovery=-
« Last post by tautech on Today at 06:10:57 pm »
As far as I know the Waverunner 2 comes with full sample memory,same as Wavepro. I looked into the service manual and did a search here (there is a member with a strange user name who seems to really know these scopes inside out and who seems to have provided most of the information about them, but it appears he has been banned?), and everything I found confirms that the sample memory size is software configurable as on the Wavepro.

I probably should try higher option code numbers, i.e 01-00000010, but to test them out like that will take forever.
Yeah it sucks that Wuerstchenhund was banned as he had a hell of a lot of knowledge to offer this forum about high end scopes and LeCroy in particular. Last I heard he'd asked to beta test SDG6000X so hopefully he's had the opportunity to add his expertise into Siglent products.

Shame others here wouldn't just listen to what he had to say instead of taking it personally.  :-//
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So you can't have a hobby?
You can. You just can't buy some types of goods (like oscilloscopes, printed circuits or milking machines) directly from foreign seller.  :-\

Or are they concerned you might out think the establishment or design some sort of subversive device?
I can't say for sure, but most of all it seems that authors of this list just don't gave a f*uck about gar(b)age tinkerers and their weird hobbies. For example: you can't (as individual) import multimeter but you can import signal generator.

But why I've successfully received multimeters and current meter from Aliexpress? F*king DHL?
Because the usual parcel (especially from China) with a fairly high probability does not attract the attention of customs, in contrast to courier services, like DHL.
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I had a whinge about that on a call with them and they said they were going to implement it. It’s apparently because their ERP and web site are completely separate.
I think that's the same excuse I got maybe 5 years ago when I mentioned it....
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I had a whinge about that on a call with them and they said they were going to implement it. It’s apparently because their ERP and web site are completely separate.
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Test Equipment / Re: HP 8657B Cooling Fan Intermittent
« Last post by RFDUK on Today at 05:59:26 pm »
Hello Brad, I've had a couple here for about 15 years, one in regular use. To confirm the fan is on continuously, I've never noticed it off after hours of use and it isn't that quiet. Great generators for low level setting accuracy and low leakage.

Some signal generator fan drivers are complex, don't know if this is one of them. Example is the iconic HP 8640A & B, zero non harmonic spurious except for AC line, low phase noise and lockable. Wonderful things.

The full service 8657B manual pdf is available on line. Regards, Martyn.
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Well, the Load passed the 50 watt stress test in CR Mode, 7.3A/7v, so all appears to be ok. Pot was set to max (~1 ohm across the MOSFET).

With a 22k input resistor and a 10K pot, the effective range of resistance load that can be dialed up is between 1 ohm and 100 ohms.

Increasing Rin will increase the top to over 100 ohm loads. Reducing Rin will decrease the bottom end and allow testing with <1 ohm loads. A practical value for Rin is probably between 10K and 100k.
enut11
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