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Dodgy Technology / Re: KCD-11 rocker switch from aliexpress is junk

« Last post by thm_w on Today at 09:03:38 pm »

The thing is some suppliers with the exact same looking part might be great. But yeah these look cheap.

LCSC has some from 10c each that I'd probably trust more: https://www.lcsc.com/product-detail/span-style-background-color-ff0-Rocker-span-Switches_SHOU-HAN-KCD11-2P-R_C5884414.html (hundreds of options just picked the first one).

Other Equipment & Products / Re: Different bases on Amscope microscope

« Last post by KE5FX on Today at 09:03:05 pm »

Quote from: Psi on Today at 11:57:59 am

Any time you bump them the microscope shakes for ages.

So don't do that.

Test Equipment / Re: Siglent SDS3000X HD and upgraded SDS1000X HD

« Last post by Martin72 on Today at 09:01:41 pm »

Speaking of scope music, I tried it briefly earlier....With ERES 16bit it's pretty cool.

I have to work through next weekend, maybe I'll have more time for scope the following weekend.

But I took a few pictures earlier and tried out the scope music briefly.
What is noticeable so far is the very short reaction time when working through the menus.
Makes me want to try out more.

Beginners / Re: Replacing SRAM IC with Flash

« Last post by xvr on Today at 09:00:07 pm »

Do not forget to add series diode to battery - lithium battery do not like when someone trying to charge it. They could blow up.

Test Equipment / Re: Using SCPI with python via telnet to connect with a siglent scope

« Last post by XiMMiX on Today at 08:54:54 pm »

your kommando function doesn't just send the command to the scope, it also returns the first reply by running self.lese_daten().
You're not doing anything with the data the kommando function returns.

Beginners / Resistor ????

« Last post by K.primdahl.8270 on Today at 08:54:12 pm »

I'm puzzled by this resistor
Can anyone help please

RF, Microwave, Ham Radio / Re: Quansheng UV-K5(8) firmware modding

« Last post by radiolistener on Today at 08:53:21 pm »

Quote from: pienari on Today at 07:51:48 pm

I backupped old fw of my K5.

How?

According to source research, I can backup entire EEPROM with this command:

Code: [Select]

./k5prog -r -v
it reads 8192 (0x2000) bytes, the last 512 (0x200) contains calibration data.

And I can write new firmware with this command:

Code: [Select]

./k5prog -F -YYY -b firmware.bin
still looking for a way to get current firmware from the radio

Beginners / Re: Replacing SRAM IC with Flash

« Last post by SiliconWizard on Today at 08:48:43 pm »

Quote from: Nominal Animal on Today at 12:48:28 am

How about using 512k×8 low-power SRAM like CY62148ESL-55ZAXI, and controlling the four highest address bits (A15, A16, A17, A18) with a 16-position absolute encoder and four pull-up resistors? With a pull-up on /CE, the stand-by current draw is just 2.5µA typical, max. 7µA, and voltage can be 2.2V–3.6V or 4.5V–5.5V. That is, you can use 2.2V – 3.6V battery backup voltage. Since LH52256C/CH uses 5V logic, the battery vs. normal operation voltage selection should be easy (higher voltage wins)

Actually, this is "better" than this. As usual with SRAM, the min. data retention voltage is much lower than its operating voltage range and the current is also much lower in practice.
The datasheet states 1.5V min for data retention. So yes, a typical CR2032 lithium battery would last a very long time and you'll get more out of it than the typical 200mAh which is given for a cutoff voltage way above 1.5V.
Add a largish cap in parallel with it, and you'll also have ample time to replace the battery when it's completely discharged, without losing any data.