Archive for the ‘computing’ category

« Older Entries
Newer Entries »

Odds and Ends

May 25th, 2010

Yesterday, I revisited this post listing on-going projects from December 2009.  Some things have changed, some remain the same.

The computer stuff has all been crossed-off the list, except that the home server is off-line with a dead power supply (or motherboard).  I’m somewhat loathe to spend any money on it, but I should be able to pick something up.

While it would probably have been cheaper to buy one of the HF/VHF/UHF combo radios, I’ve set off stupidly down the trail of building (and interfacing) transverters.  I am just three amplifier stages away from having 3-5 watts on 50 MHz!  …plus the interfacing.  I’ve decided that interfacing transverters to radios is more difficult than actually designing and building the transverters themselves.  I built the 903-MHz W1GHZ transverter during the Winter, but haven’t tried it on the air just yet.  W8ISS announced recently that he had some leftovers from the group buy of W1GHZ transverter parts, including boards for 2304 and 3456 as well as some G6Y relay kits.  I bought the lot.  I have enough MMICs and chip caps in the shop to build these and since I’ll need to order a couple of mixers for the other transverters, I can hit the Mini-Circuits minimum order.  Sometime.  Microwaves may all get pushed off to Fall and Winter.

Through a strange coincidence, my wife and I independently decided that it would be a good idea to move my ham shack.  The new location is closer to the center of activity in the house, which means I’ll operate more radio and be more accessible to her while I’m doing it.  But, the feedline and rotator cable no longer reach my 144-MHz Yagi.  Fortunately, I’ll be able to raid the K8GU coax stash shortly.  In the mean time, I’ve been missing what appear from the Hepburn maps to be epic tropo conditions.  Stuff happens.

QSLing, notably my favorite QSL topic—bureau cards.  All bureau requests for KP4/K8GU have been processed.  I ran out of CE/K8GU cards with 10 to go.  I will run some more of these from a photo printer in the next couple of days.  Piles of PJ2/K8GU, K8GU, and (go figure) AA8UP cards remain.  I will get the PJ2 cards done this weekend since I have a box of cards on-hand.  K8GU and AA8UP cards are awaiting a redesign.

Although it sounds like a lot, relatively little is getting done on any of these things thanks to an outdoor project at home.  More on this in the future.

Comments Off on Odds and Ends »

Posted in computing, engineering, hobbies, radio

Tags:

Platform Agnostic

May 6th, 2010

Are you?  Objectivity trumps hype.

Comments Off on Platform Agnostic »

Posted in computing

Computer Projects

April 24th, 2010

Worked on a couple of computer projects this afternoon:  1. Finally requested a username/password from Verizon so I could do authenticated SMTP through their server and thus end my relationship with gmail.  I did not think this was working earlier, but now it is after fixing a couple of lines in the Postfix main.cf file.  2. Thinking about IPsec VPN for home to use the iPod Touch from the road.  Ideas solicited.  3.  Still fighting with the mod_rewrite error in Omeka.  Would like to get this working.  More later…

Comments Off on Computer Projects »

Posted in computing

Trials and Tribulations of a Geriatric Electronics Specialist

February 6th, 2010

geriatrics

I have an old radio problem.  Make that three old radio problems…err…problem radios.

My first used radio was the TS-930S you see in this picture.  It’s been good to me, and I’ve tried to reciprocate, although I am a contester.  It hasn’t quite been the same since I put the third set of PA drivers in it and repaired the power supply.  Something deeper must be wrong.  I found out tonight that something deeper was indeed wrong, in the form of not one, but two, exploding electrolytic capacitors.  At least I had one of them in the junk box, but I figured I was pushing my luck and came up here to the shack to blog instead of blowing up another one.  The power supply pass transistors were assuredly toast since they were riding high at 40 volts—got that fixed.  But, it still pops caps.  Crap.  Something is amiss in the final PA bias circuit (MRF-422).  I don’t think that the ratings of the MRF-422’s have been exceeded.  So, it should be a matter of diagnosing the bias circuit and getting back on track.

The TS-700S at right is my most recent used find.  It’s in practically perfect cosmetic condition.  But, during the ARRL January VHF Sweepstakes, the output power started fluctuating before finally going to zero.  The T/R relay driver transistor failed, but there’s still something else going on—it looks like an ALC issue of some sort.  I did just finally find a service manual for this guy and that should help the diagnosis.  Although, the service manual is unusually vague about the purpose of some of the control signals that are passed between functional blocks.  This might take a while, too.

The other TS-930 actually works, except only on 40 CW.  On the other bands, the PLL unlocks.  KA5IPF suggested that I tweak the master oscillator to keep it off the ragged edge of unlock.  I’ve done that a few times and can’t quite hit the sweet spot.  My next plan is to pull the PLL unit out (a real pain) and reflow all the solder joints on the board since it comes from the early era of the TS-930, when cold solder joints were common.

I’ve pulled the FT-840 out to be the second radio for bands other than 40 CW.  And, I’m missing the Sprint tonight to spend time with my wife since I spent the better part of the afternoon tracing through the TS-700 and hooking up the FT-840.  Fortunately, I have the FT-840 configured as a drop-in replacement for a TS-930—this is in no small part due to the fact that the PIEXX boards use Yaesu-style BCD band-decoders—so, I can plug right in with the appropriate adapter.

Comments Off on Trials and Tribulations of a Geriatric Electronics Specialist »

Posted in computing, engineering, hobbies, radio

Tags:

Projects, projects, projects

December 11th, 2009

There are lots of projects going on here at the ranch and I’m not sure where to start. So, I’ll make a dreaded bullet list. A lot of this stuff has been a long time coming and I haven’t even had to spend much money on it, just time.

QSLing:

  • Some PJ2/K8GU cards are still in the queue since USPS didn’t like the “gift” (a laser-engraved poker chip) I was including with them—need to get padded envelopes.
  • No KP4/K8GU cards have been replied to since I don’t have a card design yet. This will be a photo card.
  • Plan to have all direct QSLing caught-up by the New Year.

HF station:

  • QRV on 80/40/20 with full SO2R.
  • Right TS-930S still needs a new set of MRF-485 drivers (although it puts out a few watts).
  • Left TS-930S needs PLL/master-oscillator alignment so it will go to bands other than 40 meters.
  • Built IK4AUY 2N5109 push-pull preamp from QEX article—needs finished and tested.  Have enough parts to build two, but might go with the simpler W7IUV design for the other instead.
  • Plan reduced-size K9AY for 80/40, maybe 160.
  • Plan W3NQN RX filters to go on the K9AY ahead of the preamp.

VHF/UHF station:

  • Wired in Jones plug(s) for the rotator.
  • 50-MHz transverter project is stalled awaiting parts orders (SM caps and toroids).
  • Do a planning cost analysis of 50- and 432-MHz transverter costs vs buying a used FT-817.
  • Ordered W1GHZ 903- and 1296-MHz boards and kits with W8ISS.
  • Plan PAs for 903- and 1296-MHz transverters.

Computers:

  • Bought new keyboards and mice for sakhalin and formosa.
  • Thanks to the generosity of a friend, sakhalin now has two Seagate Cheatah Ultra320 10-krpm 36-gB disks.
  • Added the old 1.7-gB IDE disk from the “ham computer” to sakhalin so I can still run TR.
  • Added the extra RS-232 ports from the “ham computer” to sakhalin for rig control.
  • In the process of configuring sakhalin to triple-boot Windows 95 (aka MS-DOS 7 for contesting TR), Windows XP (so I have it), and Xubuntu.
  • Plan to migrate formosa user data (not much of it) to sakhalin.
  • Plan to convert formosa from Xubuntu to OpenBSD using 20-gB drive from sakhalin, plus 120-gB already inside.
  • Plan to migrate crete server contents to formosa.
  • Plan to convert crete back from Ubuntu Server to “ham portable computer” running Windows 95 (aka DOS 7).
  • May run a network drop to the basement to use crete in the shop.
  • The MacBook (vieques) still just works.
  • So does the OpenWRT box (home).

And that’s just the hobby stuff!  Well, most of it.

Comments Off on Projects, projects, projects »

Posted in computing, engineering, hobbies, radio

Tags:

Hacking Engineering Education

October 25th, 2009
Bell System Manhole Cover

Bell System Manhole Cover

While browsing my local public library a few weeks ago, I stumbled across the book The Best of 2600: A Hacker Odyssey by one Emmanuel Goldstein.  Despite my own youthful adventures (perhaps chronicled in a future post) with computers and networks, I never got into reading 2600, probably for the better.  But, the book represents the best of the magazine and it’s worth reading through more mature eyes.  Why?

The hackers are playful.  They are creative under duress and with limited resources at their disposal.  They tell stories.  They share mental models of the networks they’ve compromised.  They are the explorers of the networked world.  They are social—they understand that networks connect people.

Of course, this assessment glosses over the criminal and arrogant aspects of hacking.  But, the concepts of exploring, building, and sharing knowledge and models are valuable skills for the innovators of tomorrow.  Perhaps we can learn something from the hackers?

Comments Off on Hacking Engineering Education »

Posted in communication, computing, education, engineering

Site Migration Notes

September 27th, 2009

It looks like the site migration has gone relatively painlessly.  Although, I think I lost 2-3 posts (the Square Rigger Briefcase and Angostura LLB posts are the ones I remember) in the conversion from Joomla to WordPress.  I need to reload the images from the original WordPress posts (from the blog.k8gu.com days) into the new WordPress. The images from Joomla had to be moved into the WordPress posts by hand, but since there were only about fifty posts, this was not a big deal.

I used a modified version of this script to dump my Joomla articles into a dummy WordPress installation/database table that I set up on the QTH.com server.  Then, I exported from that WordPress installation in WordPress XML format so I could test the import on my server here at home, as well as importing the old WordPress posts from pre-2008.  Bingo.  I just cleaned-out the old Joomla and WordPress files and database tables at QTH.com then replaced them with the new WordPress installation.  I’ll be adding the images from the old WordPress posts back in slowly.

Comments Off on Site Migration Notes »

Posted in computing, site

sakhalin turns 10

July 25th, 2009
Sakhalin

Sakhalin

We moved recently, hence the lack of posting to the site (the pending completion of my degree and preparations for employment have contributed to that, as well).  Among the moving dust, I discovered the invoice for the desktop computer that I bought when I started college.  It was dated 7/20/1999, ten years ago this past Monday.  The price was $2,283.29.

What did that princely sum include?

  • 17-inch CRT monitor
  • Pentium-III 500 MHz CPU (1)
  • Dual-CPU capable motherboard
  • 256 MB of PC100 SDRAM
  • Western Digital 20.4-gB hard drive
  • ATI Rage Xpert 128 16 MB video card
  • Adaptec 2940U2W Ultra-Wide SCSI card
  • Iomega Zip drive
  • SCSI CD-ROM
  • 3Com 3C900 Ethernet card
  • Microsoft Windows NT 4.0
  • Microsoft Office 2000 Small Business

If I was going to spend that much again, I would have done it slightly differently, ditching the expensive SCSI hardware that I never ended up exploiting and buying the second CPU right away.  But, this was a great machine—I was probably the first student with 256 MB of RAM, certainly no one else on my dorm floor had it.

Windows NT never quite worked right with everything.  But, then again, neither did Linux.  The ATI Rage Xpert 128 was not supported in X for at least six months after I bought the system.  Linux was less of a pain than Windows and so, I operated from the console for my first two quarters of undergrad.  People often ask how I learned Linux.  You learn fast when you have no option but the command line.

This computer was the beginning of a tradition: naming computers after islands.  I named it ‘sakhalin.’  I asked for a static IP address and received the DNS entry sakhalin.onu.edu (which at the time pointed to 140.228.23.4).  This was the first of many islands:  mauritius.onu.edu (the Radio Free Maglott/Radio Free Roberts server), roatan.onu.edu (a 486 that I ran FreeBSD on for kicks), curacao.onu.edu (another 486 that ran Linux), palau.onu.edu (the special projects machine), tahiti.onu.edu (my iBook).  Those machines have all since past.  Although, I still have crete (my secondary web server), vieques (my MacBook), formosa (home Linux machine), and of course, sakhalin.

Over the years, I upgraded sakhalin to two Pentium-III 500 MHz CPUs.  (I actually bought the CPU via an eBay auction using Lynx—a fun piece of trivia.) The power supply needed an upgrade at this time, too.  I also added 512 MB of RAM and a SCSI CD-RW drive.  The Ethernet card is now an Intel EEPro 100Mbit/s card and the video card is an ATI Radeon with 64 MB of RAM.  I replaced the monitor with a 19-inch Dell Trinitron, which is beautiful.

And then, there is software.  sakhalin has run every GNU/Linux major kernel version since 2.0.36: 2.0.x, 2.2.x, 2.4.x, and 2.6.x.  It has run at least four different distributions:  RedHat, SuSE, Gentoo, and Xubuntu.  It has also run Windows NT 4.0, Windows 2000, and it is currently running Windows XP.

sakhalin has been a good and reliable performer, although I get the occasional unknown error message.  It has recently moved to replace the Pentium 166 that I had been using to manage my contest station.  I’m looking forward to many more years of faithful service…

» Read more: sakhalin turns 10

Comments Off on sakhalin turns 10 »

Posted in computing, life

Linux and the Holidays

December 8th, 2008
TO-3 ornament

TO-3 ornament

Things have been busy around here with the holidays (past and future) and trying to prepare for life after graduate school (and trying to wrap-up graduate school). There’s still lots of data to be analyzed, models to run, and even two groups of instruments to field.

Some brainstorming over the past two weeks yielded a couple of good ideas for projects. More on these as/if they come to fruition. In the mean time, I’ve been trying to get a full-size (as opposed to my OpenWRT box) Linux machine running at home again. Sarah’s old computer doesn’t have enough RAM, what RAM it has is RDRAM. So, I tried to put Xubuntu 8.04.1 LTS on my old desktop machine (the venerable sakhalin).  It’s been having a war of words with my Western Digital WD205AA hard drive.  I think it might actually be working tonight.

Yesterday’s attempt at Xubuntu 7.10 was an exercise in frustration.  Sarah was putting lights on the tree and I was generally a scrooge.  Fortunately, I saw a TO-3 transistor on my workbench and realized that I could easily make it into an ornament.  That cheered me up.  I’m sure the idea’s not new.  But, the little things make all the difference.  Christmas is coming.

» Read more: Linux and the Holidays

Comments Off on Linux and the Holidays »

Posted in computing, life

Trivial Gallery v1.0.0

October 24th, 2008

I wrote up a little Perl script that builds a gallery out of pictures organized in folders in order to host a gallery on my DSL router running OpenWRT.

Try it here. 

Get it here.

» Read more: Trivial Gallery v1.0.0

Comments Off on Trivial Gallery v1.0.0 »

Posted in computing, photography