Linux

Unless you’ve been hiding under a rock, you’ve probably heard that Microsoft won’t be supporting Windows 7 home, (what many of you may be running on your PC right now) by the end of this year (drop dead date is 1/14/2020).  So if that’s what you’re running you’ve got till then to decide how you’re going to upgrade your computer.

The obvious choice, and the one that Microsoft recommends is Windows 10.  What happened to Windows 8 and 9?  Well W8 was the successor to W7, and there was a W8.1 as well.  However, it wasn’t until what would have been W8.2 that M$ finally managed to get things right.  Their marketing department decided to cut their losses and just release the respun operating system as Windows 10.  They leapfrogged over Windows 9, to avoid confusion with the Windows 9x family of releases.  Guess they didn’t want to be accused of polishing a turd twice.

Not that Windows 10 has a clean reputation either.  The operating system was caught performing upgrades without the user’s consent, and M$ even managed to ship a broken upgrade that crashed users computers.  Then there are the privacy violations with W10 phoning home to Redmond with the users personal data, you know to better provide you with a great experience (like to sell you shit).  Eventually, the word got out as how to disable most of this stuff, but not before a lot of users got really pissed off.
Then there is the not so secret fact that Microsoft desires to eventually stop selling Windows and rent it.  So you’ll be paying them an annual fee for the privilege of running the latest Windows, like it or not.

So, are you ready to upgrade to Windows 10?  Perhaps you’re thinking of giving M$ the finger and will buy a Mac?  Really?  I won’t go into all the stuff that Apple has done to their once wonderful computer, but let’s just say they’ve been keeping up with their buddies in Redmond.  When you buy your Mac, make sure you specify all the memory and disk space you’ll ever need because you can’t upgrade the machine.  Everything is soldered in place, CPU, memory, solid state disks (no more rotating disks in Mac books).  You can’t even open the computer anyway, they are glued together.  When your battery goes bad, you’ll have to replace the whole laptop, or have it permanently tethered to its power brick.

There is another option though, and you already know what I’m going to tell you.  Upgrade to a Linux operating system (a BSD operating system is another choice, but we won’t go there for now).

Technically, Linux isn’t an operating system, it’s just the kernel of one.  The Linux kernel contains the system smarts that enable a computer to run multiple programs at once (actually switching between them in rapid succession).  It manages memory usage, disk files, and hardware drivers.  What the kernel doesn’t provide is the user interface (either graphical or command line), start up and shut down logic, and all of the system applications that control and configure everything.

Operating systems which are called ‘Linux’ are called distributions, and there are hundreds of different ones.  Since almost all of them make use of the same basic kernel (with various custom mods) along with a standard set of system apps from the GNU project, almost every application written for ‘Linux’ can run an all of these distributions.  The difference between these systems is the presentation layer to the user, that is what the desktop screens look like, the key shortcut mappings, and the choices of what programs were included with the installation.

Short history:  The Linux kernel was developed by Linus Torvalds in 1994 as a college project.  He wanted to create a Unix like system with all original code.   While Linus was the original author and maintainer of Linux, the kernel is now maintained by an army of on-line supporters, with Torvalds still having the final say over things.
Meanwhile, another computer hacker (not to be confused with the ‘black hats’ that try to break into systems) named Richard Stallman set out to build an entire Unix like operating system.  Stallman started by creating open source versions of every system program that was part of Unix, including the compilers, linkers, and C libraries needed to build other programs.  Eventually, he had everything he needed, except a kernel.  Stallman’s most famous program is probably the Emacs editor, a real Swiss army knife that can not only edit, but even play games, debug other programs, and serve as a user interface shell.  This set of programs is called the GNU system, which when combined with the Linux kernel, finally provided the goal of a totally free (both as in beer and as in speech) Unix like operating system.

Eventually, the Linux kernel was adopted for use in systems other than Unix like computers.  Android phones use the Linux kernel.  Chromebooks use the Linux kernel.  The Tivo video recorder uses it.  Lots of gizmos with embedded computer systems make use of the Linux kernel (lots also use Windows, have you ever seen the ‘blue screen of death’ on an electronic billboard?).  Billboard BSoD

But you say, can I run the same programs I am now using on Windows with Linux?  Maybe.  The Firefox and Chrome browsers have Linux versions.  Many other Windows programs can be installed under Linux using the Wine utility.  There is a commercial utility that you can buy that will enable Microsoft office and many other programs to be used.  crossover   There are also many opensource free programs that perform the same functions as many of the Windows programs you are now using.  The Libreoffice suite, for example, is a complete office package that can replace the Microsoft one.  It will even read and write MS office files (not 100% perfectly, some formatting differences exist, but it’s very very close).  The Gimp image editing program does the same job as photoshop, some say it’s even better, but you will have to learn how to use it.  The steam gaming platform supports many windows games on Linux. ( steam )
Finally, there are lots of Linux specific apps for Ham Radio, and many of the Amateur radio Windows apps will run on Linux via wine.

So how do you install Linux?  Download an ISO (DVD/CDROM) image for one of the distributions, copy the file to a DVD-R disk or a USB flash drive, set your computer to boot from the media (usually Del, F2, or  F12 during boot up).  This might involve a setting in the bios.  Then once the image loads, follow the directions.  You might want to print the installation manual on the distribution’s web site first.

Which distribution?  The two I’d recommend first would be any of the   Ubuntu or  Linux Mint  flavors.   Both of these are based on the Debian distro, one that has been around almost as long as Linux itself.  (Debian is a rock solid OS, but it’s really not for beginners.) With Ubuntu you have the choice of the  Gnome, LXDE, XFCE, MATA or KDE  desktop environments (Ubuntu, Lubuntu, Xubuntu, Ubuntu-Mate, Kubuntu).  Linux Mint supports the Cinnamon, MATE, and XFCE DE’s.   I’d recommend either Cinnamon or KDE for the most Window’s like experience, though all of the above are good choices.  Ubuntu with the Gnome desktop is the most unusual of them all.  While Gnome’s workflow is excellent, you really have to re-learn how to navigate the system all over again.  Installing the Cairo-Dock (Mac like program launcher) might help you keep your sanity when transitioning to Gnome.

I’ve been running Linux on my own computer since 1996.  I’ve switched distributions a few times.  I’ve used Debian, Red Hat, Slackware, and Gentoo before settling on Ubuntu and then Linux Mint.  (Now that Linux Mint has abandoned their KDE version, I’ll probably go back to Ubuntu-Kubuntu).
I’ve only scratched the surface here, and I’ll probably re-visit the subject in another post.

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Building a Transceiver, more thoughts

recently ran into a few videos on YouTube featuring the Collins KWM-380, and the Heathkit SB-104A transceivers.  Both of these radios are contemporary, the years in which they were made overlap.  However there is QUITE a HUGE difference in the price of these rigs, the Heathkit being nearly an order of magnitude less expensive than the Collins.

Both rigs have quite simple front panels with few controls (compared to today’s rigs!).  Both have an analog S-Meter that also monitors other parameters during transmit, and seven segment frequency displays without an analog dial.

The SB-102 reads out the operating frequency to the nearest 100 hz by use of a frequency counter.  It computes the on the air frequency from the sum and difference of the crystal HFO frequency in the first conversion, the second conversion VFO frequency, and the carrier oscillator-bfo frequencies.  The displays use neon plasma type devices.  It is not easily possible to add WARC band coverage to the SB-104 (it might be possible to give up some of the 10 meter band positions and make some major modifications to add different crystals and band pass filters on these positions.  The 12 meter band would be the easiest to add, and perhaps the 15mhz WWV position could be modified to work on 17 meters.)

The KWM-380 shows its operating frequency to the nearest 10 hz on red 0.56″ seven segment  LED displays.  A PLL frequency synthesizer is used in the first conversion, and digital logic (micro-processor) is used to control the PLL and displays.  The KWM-380 did not have a band switch, this was done by using a tuning rate of 1 mhz / step.  As the KWM-380 was a feature reduced version of government radio, it was possible for Collins to add transmit ability on the WARC bands to the radio via a firmware update.  Owners of these radios were able to also add the 60 meter band many years later!

The Heathkit transceiver uses much the same conversion scheme as the earlier members of the SB10x family, a variable first IF centered on 8.5 mhz, and a second IF at 3.3 mhz.  Two different crystal filters in the second IF provide bandwidths of 2.1khz, or 400khz.

The KWM-380 up-converts to a first IF of 39mhz, and then down to a second IF of 455khz.  A third conversion is made to 6.255 mhz., and a final conversion back to 455khz.  Several 6.255 mhz crystal filters with different bandwidths may be selected.  The purpose of the final two conversions is to move the bandwidth of the 6.255 mhz filter in reference to the the carrier oscillator frequency.  This allows for removing the influence of a close by signal, at the expense of an non optimal placement of the bfo signal.   It should be pointed out that many of the later Japanese radios offered this ‘passband’ tuning feature, along with a notch filter AND a variable bandwidth feature.

I’m giving some though to some kind of ‘old school’ approach to a transceiver design that would look something like a cross between these two rigs, at least from the front panel.  I like the idea of large LED’s for the frequency display (either 0.6″ or 0.8″ in size, I have some of both).  I’d use an AD995x series DDS instead of a VFO or PLL, which would give better performance than either the Heath LMO or the Collins synthesizer.  I have some 9mhz crystal filters and also some 455khz Collins filters in the parts bin, so a variable bandwidth IF setup is planned for.  I don’t know if I’d use a 45mhz first IF (which would allow for general coverage on receive) or use the 9mhz IF as the first conversion.  Both could be included and switched in as desired.  I have two different cabinets I could use, a large (almost relay rack sized) one, and a smaller box (that’s still a bit larger than many current Japanese transceivers).  I could fit the rig, speaker, and power supply in the larger box, but I’m partial to the smaller one.