No more printing woes

Linux uses the CUPS printing system (provided by Apple). Usually, one can just plug a printer into a Linux machine and it will be instantly recognized. This is so much easier than downloading and installing drivers on a legacy system.

On the odd occasion that something is amiss, printing a document from the command line can pinpoint the issue. When you execute a command manually, you can see the error messages and then google them, or look for a solution on http://forums.fedoraforum.org.

Use lp or lpr to send a document to the default printer:
$ lp filename

or to print to a specific printer:
$ lp -d printer filename

Sometimes it is easier to send a file directly to a printer than to launch an editor just to open and print a file, for example:
$ lp -o landscape -o fit-to-page -o media=Letter filename.jpg

CUPS understands many file types directly, such as PDF, postscript, text, or pictures!

Sometimes, when you are busy installing a new machine, you may wish to print something, but the printer may not be installed yet. Try sending the job to a different machine:
$ lp -h 192.168.x.y filename.pdf

La voila!

Comments

Parasitic Quadrifilar Helical Antenna

This article was reprinted in OSCAR News, March 2018: http://www.amsat-uk.org If you want to receive Satellite Weather Pictures , then you need a decent antenna, otherwise you will receive more noise than picture. For polar orbit satellites, one needs an antenna with a mushroom shaped radiation pattern . It needs to have strong gain towards the horizon where the satellites are distant, less gain upwards where they are close and as little as possible downwards, which would be wasted and a source of noise. Most satellites are spin stabilized and therefore the antenna also needs circular polarization, otherwise the received signal will flutter as the antennas rotate through nulls. The helical antenna, first proposed by Kraus in 1948, is the natural solution to circular polarized satellite communications. It is a simple twisted wire - there seems to be nothing to it. Various papers have been published on helix antennas, so the operation is pretty well understood. Therefore,

To C or not to C, That is the Question

As most would know, the Kernighan and Ritchie C Programming Language is an improved version of B, which is a simplified version of BCPL, which is derived from ALGOL, which is the Ur computer language that started the whole madness, when Adam needed an operating system for his Abacus, to count Eve's apples in the garden of Eden in Iraq. The result is that C is my favourite, most hated computer language , which I use for everything. At university, I learned FORTRAN with punch cards on a Sperry-Univac, in order to run SPICE, to simulate an operational amplifier. Computers rapidly lost their glamour after that era! Nobody taught me C. I bought the book and figured it out myself. Over time, I wrote a couple of assemblers, a linker-locator, various low level debuggers and schedulers and I even fixed a bug in a C compiler - not because I wanted to, but because I had to, to get the job done! Much of my software work was down in the weeds with DSP and radio modems ( Synchronization,

Weather Satellite Turnstile Antennas for the 2 meter Band

NEC2, 2 m band, 146 MHz, Yagi Turnstile Simulation and Build This article describes a Turnstile Antenna for the 2 meter band, 146 MHz amateur satcom, 137 MHz NOAA and Russian Meteor weather satellites. Weather satellite reception is described here . A quadrifilar helical antenna is described here . Engineering, is the art of making what you need, from what you can get. Radiation Pattern of the Three Element Yagi-Uda Antenna Once one combine and cross two Yagis, the pattern becomes distinctly twisted. The right hand polarization actually becomes visible in the radiation pattern plot, which I found really cool. Radiation Pattern of Six Element Turnstile Antenna Only a true RF Geek can appreciate the twisted invisible inner beauty of a herring bone antenna... Six Element Turnstile Antenna Essentially, it is three crosses on a stick. The driven elements are broken in the middle at the drive points. The other elements can go straight throug

Aeronetworks sro - Airborne Linux

Search This Blog