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From: Jan Panteltje <alien@comet.invalid>
Newsgroups: sci.electronics.design
Subject: Re: Grounded grid VHF front-end
Date: Sun, 17 Nov 2024 16:42:27 GMT
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On a sunny day (Sun, 17 Nov 2024 14:50:58 -0000 (UTC)) it happened
antispam@fricas.org (Waldek Hebisch) wrote in
<vhcvsg$28q26$1@paganini.bofh.team>:

>Jan Panteltje <alien@comet.invalid> wrote:
>> On a sunny day (Sun, 17 Nov 2024 01:34:45 -0000 (UTC)) it happened
>> antispam@fricas.org (Waldek Hebisch) wrote in
>> <vhbh7j$26abk$1@paganini.bofh.team>:
>> 
>>>Jan Panteltje <alien@comet.invalid> wrote:
>>>> 
>>>> What bothers me today (thought maybe use an extra Raspberry Pi) is that prices
>>>> are going up to insane lavels for a Raspi5 8 Gb + supply + housing + sdcard to above 120 USD:
>>>>  https://www.sossolutions.nl/raspberry-pi-5-8gb-starter-kit-compleet
>>>> 
>>>> For just a bit more you have a decent mini computer:
>>>>  https://www.aliexpress.com/w/wholesale-mini-pc-x86.html
>>>> 
>>>> Inflation?
>>>> Time to end raspi stuff and look for other solutions.
>>>
>>>I bought Raspberry Pi 1B when they appeared, but after that used
>>>Chinese alternatives. 
>> 
>> Same here, have some old Pi2 versions...
>> one Pi2 is on 24/7 running a server, measuring air pressure, radiation,
>> this Pi4 8 GB I use for web browsing and Usenet
>> a Pi4 4 GB records security cams and plays audio, records airplane traffic (with dump1090)
>> and lots more stuff...
>> 
>>>Orange Pi used to be cheap, most is more
>>>expensive now.  But Orange Pi Zero 3 is reasonably priced and
>>>powerful enough for my purpose.  You apparently want PC class machine,
>>>for this I want real PC.
>> 
>> I have several 'real' PCs.. but those are big and use a lot of power, have DVD burner, huge harddisks, 
>> Almost never on these days, stopped burning optical disks, almost all USB harddisks for data storage now.
>
>I mostly depend on storing data on multiple HDD-s (my PC have mirrored
>pair of discs and I have extra discs for backup).  In last several years
>I did not burn any DVD-s, but maybe I will do some with importand data
>for extra safety (DVD are too small for bulk data).

Blu-ray discs are 25 GB...
From my dvd-list.txt file for disc 998:
998
Tue Oct  8 12:43:07 CEST 2019
BD-R25GB  <---disc type
Mediarange 4x inkjet printable
LG BH10LS38 <---burner type
PLEASE STOP ANY RTL_SDR write data errors observed when that is running! <--- warning!
Make sure you have enough disk space.
dd if=/dev/zero bs=100000000 count=242 > bluray.iso
mke2fs  bluray.iso
mount -o loop=/dev/loop0 bluray.iso  /mnt/loop
cp ... /mnt/loop/
du /mnt/loop
#umount /dev/loop0
umount /mnt/loop
cd /mnt/sda1/video/satellite
growisofs -speed=4 -dvd-compat -Z /dev/dvd=bluray.iso
dvdimagecmp -a bluray.iso -b /dev/dvd                
# df
/dev/loop0       23261268  21022524    1057104  96% /mnt/loop
# l/mnt/loop/
total 20977548  
-rw-r--r-- 1 root root      19095 May  7 23:33 xinutop_manual.txt
-rw-r--r-- 1 root root 4385000000 Jul  1 18:01 freibeuter_des_todes_german.ts               amovie
-rw-r--r-- 1 root root         58 Jul 11 10:40 xinutop-nav-x86-2.4.img.md5
-rw-r--r-- 1 root root  682624000 Jul 11 10:44 xinutop-nav-x86-2.4.img
-rw-r--r-- 1 root root 4294705152 Sep  8 01:51 stones_havana_NPO_3-20190907213907-.mts      amovie
-rw-r--r-- 1 root root  627385344 Sep  8 02:28 stones_havana_NPO_3-20190907213907-.mts1     amovie
-rw-r--r-- 1 root root 3949971456 Sep  8 05:59 stones_havana_NPO_3-20190907235958-.mts      amovie
-rw-r--r-- 1 root root 1993500000 Sep 24 16:53 the_great_wall_2016.ts                       amovie
-rw-r--r-- 1 root root 2354400000 Oct  3 17:05 last_man_standing_1996.ts                    amovie
-rw-r--r-- 1 root root 3172370000 Oct  8 12:39 a_cure_for_wellness_2016__german.ts          amovie


all from satellite...
I wrote dvdimagecmp to verify the burned image..


I stopped when my 1000 DVD box was full:
 https://panteltje.nl/pub/CD_box_binnenkant_IXIMG_0549.JPG
  that has everything from old CD-RW, blu-ray, to M-DISCs

M-DISCs are supposed to last a long time:
 https://en.wikipedia.org/wiki/M-DISC
Stuff I wrote , OS versions I downloaded, music, videos, stuff I designed...
If you keep the optical media in the dark then it lasts more than 25 years...
Each disk has a number, 1 - 1000 in this case, and I have a large text file with the contents of each number.
Easy to search with a text editor.
Many discs are special format, some huge with Reiser filesystem.
I was reading Linus wants to drop Reiserfs..
I may leave linux and write my own OS, or use some other Unix.
wrote a Z80 multitasker once long time ago.. Not a big deal.
Keep the old Linux distros!



>I depend on data stored on HDD, most is fetched from Internert but
>things vanish randomly from the net and I have my own indices of
>interesting data, so I normally use local copy from my disk.  Also,
>have some compute intensive stuff.
>
>>  >For light use mini-PCs may be enough and
>>>are quite cheap.  I got one for equvalent of $70, 6GB RAM, dual core
>>>Celeron N3350, 64 GB solid state disc, 2 USB 3.0 slots (+ 2 USB 2.0),
>>>LAN, Wifi, of course in case and with included power supply.  For
>>>me important advantage is that there is no fan (passive cooling only).
>>>Less powerful used mini-PCs can be as cheap as equivalent of $5.
>> 
>> Sound good, x86 based is nice too, have written lotd of stuff for that
>> 
>>>Supposedly some "TV boxes" are cheap, resonably powerful and can
>>>be programmed with Linux.  But I did not try one.
>> 
>> Indeed, I have several satellite reception boxes, HD recording and playback no problem with those
>> some have internet connection too, record to USB SD stick.
>> When full with stuff I like to keep I copy it to a 4 TB Toshiba USB harddisk connected to my Pi4 8 GB.
>> 
>> I do have a satellite reception PCI card in an old x86 PC too, but that is not HD.
>> But wrote a lot of software for it.
>>  
>> 
>>>Pi-s are better for electronics/automation thanks to available
>>>interfaces, but that needs much less compute power (camera is the
>>>only high bandwidth interface that I use).
>> 
>> Yes, GPIO is nice, on the PCs I uses the parport for I/O, 
>> even specifically bought a parport PCI card for that on ebay..
>> 
>> Much goes via ethernet these days and that works fine on Rspberry too.
>> Building / designing things with ethernet interface is not that hard.
>> severl projects on my site:
>>  https://panteltje.nl/panteltje/newsflex/download.html
>> USB is also fast enough for many things.
>
>USB can do milliseconds, ethernet hundreds of microseconds, small
>micros can do much better.  Theoretically with a micro connected via USB
>one can synchronize clocks of the micro and PC with microsecond
>accuracy, I plan to try this but do not know how this will work.
>
>>>When you are satified
>>>with lower compute power there are some cheap ones.  I am trying
>>>now Milkv Duo.  Radxa ROCK also seem to be reasonably priced.
>>>But once you want faster CPU, more RAM, EMMC, etc they are getting
>>>more expensive.  I am not sure why, memory modules for PC seem
>>>to be cheaper than price of adding memory to SBC-s (possibly this
>>>is just pure marketing).
>> 
>> Yes, a lot of marketing is involved
>> You get sort of addicted to GPIO with Raspberries...
>> Anyways how much processing power do I really need?
>> 
>> I program a lot of stuff in asm for Microchip PICs:
>>  https://panteltje.nl/panteltje/pic/index.html
>
>Nice.  I have avoided PICs, using now mostly STM32 and coding in C.
>One can create quite small and efficient programs in C.  I use
>assembler when I feel it is better but currently that is mainly
>for delay loop.  Doing all in efficient assembler would be large
>effort for moderate gain (maybe 20% efficiency/size improvement),
>and IME "easy assembler" tend to be less efficient than C.

In case of small micros like PICs you are so close to the hardware that you will need
to know how the various registers and stuff work anyways, no space / too much risc to allow for a compiler to change things.
Then C or some other high level language makes little sense.
After programming a few PICs you have build up an asm library and things become simple, repeats.
I use somebody else's integer math library.
Have not needed floats yet.. not even here in Fourier transform:
 https://panteltje.nl/panteltje/pic/scope_pic/
And I opensource everything.


>> This world creates bloat sftware so it can sell new hardware, Microsoft has shares in hardware companies,
>> so new bloat needs new hardware.. more money
>
>I dislike bloat but OTOH thanks to bloat powerful PC-s are available
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