2020-04-13 Beeping -- --- .-. ... . loud enough (2) 2 months ago
Today I had time to work on the transistor switching to make the morse oscillator work. As I noticed before the Kent Morse practise oscillator kit is powered directly via the key which draws more current than the nanokeyer I built can handle. So I had to calculate a transistor switch. That's something I learned a long time ago when I did electronics trade school from 1985 to 1989. In Dutch: MTS electronica. That knowledge had to be dug up again when I did the advanced radio amateur course but since I didn't have to use that knowledge it all sunk away. But, google to the rescue and I found lots of examples, but the easiest one was at Transistor as a Switch - ElectronicsTutorials which explained exactly what I wanted. The next item was 'which transistor'. The default NPN transistor is the BC547B, but the theoretical current through the oscillator is a bit more than this transistor can handle. But a fellow amateur had a few BC337 transistors spare in his junkbox, so I could continue with this project. Today I did the drawing and the calculations. I looked up the specifications for the BC337 in full saturation, at which time the Vbe is 1.2 Volt, Vce is 0.7 volt and Ibase is 1 milliAmpere. So I ended up with a resistor of 6800 Ohm at the input (which is (9 Volt - 1.2 Volt)/1 millAmpere rounded) and after building it on a breadboard it went beep with an input current of somewhat over 1.0 milliAmpere. Update: Second test was with the nanokeyer, which first gave no sound, but that was due to me turning the volume down on the practise oscillator. Turning it back up fixed the problem, and I now have loud morse! In the end this is giving me a good feeling. I had a kind of problem I haven't had to solve in ages so I had to relearn how to solve this, I found the solution method and was able to apply it in theory, practice followed the theory and it all worked as designed.
2019-12-02 Remembering the IBM PC RT.. and its powerusage 7 months ago
For a number of years between 1993 and 1997 I not only had a BBS running at home but also an IBM RT 6150 computer. It was a bigtower I got for free including the system floppy disks. I had to reinstall it because I had no idea of the root password and the only contact at the previous owners wasn't willing to give it up. So I swapped 1.2 megabyte 5.25 inch floppies for a while until I had a complete running system with AIX complete with graphical environment and a working TCP/IP stack. The IBM RT 6150 I had came with 3 builtin harddisks (full-height). For as far as I remember those were 70 megabyte each. Eventually I had enough AIX installed to also have a working compiler. One downside of this system was the powerusage. It used quite a lot of electricity. The rest of BBS Koos z'n Doos also used a lot of power. When I moved out of my parents' house in a December month the effect on the electricity bill was remarkable. Next December my parents got a call about what changed because the electricity bill had halved. And I did put 'computers' on the form for the new electricity contract but that same december I received a bill because the electricity for that house was double what the electricity company expected.
2019-10-24 Nog een https upgrade 8 months ago
Ik ontdekte dat de website van de HCC PCgg netwerkgroep nog prima draait maar wel als onveilig in een moderne browser werd aangemerkt omdat er invoervelden in zitten. Ook al is de laatste activiteit op de site van Augustus 2012 wil ik toch deze site in de lucht houden omdat ik toen heel veel lol heb gehad met de netwerkgroep en het leuk was om daar presentaties te geven en dingen uit te zoeken. Dus de site draait nu met een LetsEncrypt certificaat op https. En het was een mooi moment om gelijk de versie van serendipity zelf bij te werken. Update: Ik zie nu ook browsers die alle http gewoon als onveilig melden. Het is denk ik tijd om de laatste sites ook over te zetten naar https.
2019-10-20 Restored the webcam site and archives 8 months ago
I was looking at the overview of most requested but not available URLs and noticed there is still traffic to http://webcam.idefix.net/. For years that was the webcam site when I still had access to a reasonable location for putting up a webcam. First a good view at my previous house, and later a window with a good view from a server room at work. So I dug up the archived images and scripts, cleaned them up and made them available again. There are no fresh images, just the aged archives.
2019-08-26 3000 items on my homepage and counting 10 months ago
I was just wondering about the number of newsitems on my homepage and did a check. An interesting value popped up: 3000. Yes, a round 3000 items since I started writing more than 20 years ago (or rather: 7456 days ago) : I've created a virtual bookcase with an overview of books I like/read. Graphic created with Retro Wave. Hat tip to Wil Wheaton, who mentions 6584 days - Wil Wheaton dot net
2019-07-25 First onewire stats ageing out 11 months ago
I was looking at some onewire temperature stats and noticed the first stats being aged out. I started monitoring temperatures with 1-wire sensors in January 2007 using rrdtool. I set up round robin archives with an expiry in 11 years, and those 11 years have passed now for the first measurements.
2019-07-10 Einde van (weer) een tijdperk: geen DVB-T meer in Nederland 12 months ago
Op 9 Juli is de laatste omschakeling van DVB-T naar DVB-T2 geweest in Nederland, waarmee DVB-T ten einde gekomen is. In de ether is dus van 2 oktober 1951 tot 10 december 2006 analoog uitgezonden en van 10 december 2006 tot 2 oktober 2018 (eerste regio) - 9 juli 2019 (laatste regio) in DVB-T. De Samsung televisie die we aangeschaft hebben in mei 2013 snapt er niets meer van bij een scan op het UHF spectrum. Vooraf had ik gezocht of deze televisie DVB-T2 en de gebruikte codec ondersteunde en dat was wat onduidelijk, het hing af van de taal van de handleiding. Uiteindelijk werkt het dus duidelijk niet, de scan voor digitale tv signalen levert helemaal geen resultaat op. Dus we hebben geen NPO 1/2/3 meer free-to-air wat we gebruikten sinds de prijsverhogingen en wijzigingen van Ziggo in 2015. Bij een eerste test bleken de livestreams van de NPO applicatie met chromecast ook te werken. Alleen heeft een hapering van de internetverbinding ook gelijk het gevolg dat de televisie stopt. Het voelt wel raar om voor 'broadcast' televisie een stream aan te zetten, maar dat zal wel liggen aan de geschiedenis die er voor mij achter zit.
2019-01-12 Enabling some old web userdirs 1 year ago
I received a "complaint" that a very old site on the webserver wasn't working anymore. I am not a person to just stop something without planning that so this was an oversight. It was one of the userdirs on idefix.net: Ivo van der Wijk who hasn't updated the page sinds 1994. No, really, not even the broken links. In restoring this one and the others I found that php in userdirs is disabled by default nowadays, found via PHP not working in userdir (public_html) - devPlant. Maybe a good idea, but I only enable php on virtualhosts where I want it, so I disabled that rule. I hadn't missed it on my own webspace yet, but a site like Het online dagboek van hester (Renate) in Australie (en daar in de buurt) depend on PHP completely. While I was looking for the reason the php failed I also noticed that /etc/apache2/mods-available/userdir.conf also has some configuration I do not appreciate, it enables userdirs globally when the module is loaded:<IfModule mod_userdir.c> UserDir public_html UserDir disabled root <Directory /home/*/public_html> AllowOverride FileInfo AuthConfig Limit Indexes Options MultiViews Indexes SymLinksIfOwnerMatch IncludesNoExec Require method GET POST OPTIONS </Directory> </IfModule>I disabled that part: I only want the userdir to work on specific virtual hosts.
2018-10-21 One of my first radio contacts (re)confirmed 1 year ago
From time to time I check whether eQSL has new incoming confirmations for PD4KH contacts. Recently I found one for a contact that goes way back, and it was before I used a linux radio logging program so I did not have the details stored in my logging program. But my website still has those details: Vanavond vanuit de achtertuin contact met PI4HAL via repeater PI3UTR. It turns out PI4HAL decided to stop sending out paper cards and started using eQSL. I guess they uploaded all old logs. I do remember the contact and being nervous about actually talking "on the air" and finding my turn between other callers to that station. This was a trigger for me to check my old logs and make sure I upload things correctly to ARRL Logbook of The World including the few satellite contacts. Oh and I never started using hrdlog as PE4KH. It did not add a lot for me.Read the rest of One of my first radio contacts (re)confirmed
2018-09-24 After 25 years with sendmail there was still something to improve 1 year ago
I still like running sendmail on my own systems. But sendmail evolves with time and my configuration does improve slightly sometimes, such as on the introduction of authenticated smtp with secondary passwords. After the recent upgrades to the home server there is a new mail server with some other new details and suddenly other systems at home could not relay. A bit of searching found Best practice: sendmail and SMTP auth with the right flags for the DAEMON_OPTIONS to only offer authentication on port 587 (submission). I noticed the local systems tried relaying via port 587 so I changed this to port 25 where IP-based relaying is allowed. No idea why I set this up to use the port 587 when I set it up previously. And yes, I checked it, I started with sendmail in 1993, so 25 years of sendmail on port 25. I did start with writing my own sendmail.cf rules but I switched to .mc based configurations.
2018-09-14 IT attacks in higher education have interesting holiday patterns 1 year ago
According to this article: Students blamed for university and college cyber-attacks - BBC News the new pattern is that attacks on IT systems in higher education happen in active times in education. Interesting quote (for me):There was a very sharp decline in attacks in the Christmas, Easter and summer breaks and during half-terms - with attacks rising again sharply when terms resumed.I remember starting in system administration and learning quickly that the Christmas holidays period was the busiest period in attempts to break in to computer systems all over the world. This was simply explained by the fact that the Christmas holidays are the most universal school holiday in the world and all the teenage hackers had time to play with computers, modems and networks.
2018-07-10 Found the original article about Steven K. Roberts and his recumbent bicycle Behemoth 1 year ago
I noticed the Nomadic Research Labs site was cleaned up a bit more, so I searched again for the article that I read in August 1995 about Steven K. Roberts and his recumbent bicycle Behemoth: "Big Electronic Human-Energised Machine ... Only Too Heavy". The scans are at BEHEMOTH in Kijk – Dutch Magazine. Interesting detail is that the top left text refers to a picture of a Challenge recumbent. I recently ordered a new Challenge recumbent! Maybe I should find out whether I can find that page of that magazine. Several things can be related to seeing this article: buying the book Computing Across America, selecting a recumbent bicycle later in life and this idea in the back of my head of future recumbent cycling trips.
2018-04-06 25 years of Linux use 2 years ago
In looking at a problem with the linuxcounter script I noticed I am now passing the 25 years with Linux mark. I first saw it in the beginning of 1993 when part of my internship happened at the 'expa' lab of Hogeschool Utrecht with SLS Linux. Anyway, still using Linux a lot. It's been an interesting 25 years!
2018-02-01 TV plannen van 50 jaar geleden 2 years ago
Iedere maand verschijnt er een Electron van 50 jaar geleden op Electron 50 jaar geleden en daar kijk ik graag even in, om het 'nieuws' op amateurradio gebied van 50 jaar geleden te zien. In die van Februari 1958 viel me een stukje op onder het kopje "Televisie" met:Voor onze lezers is het wellicht interresant, te weten dat Philips op Maandag het normale TV-programma relayeert in band V: beelddraaggolf 772,25 MHz, geluidsdraaggolf 777,75 MHz. Amateurexperimenten in deze band zijn van veel belang, want ondanks de ontvangstmoeilijkheden, die er nog zijn, kon het toch wel eens dé TV-band van de toekomst blijken te zijn. Een voordeel van deze band is natuurlijk in de eerste plaats het grote aantal beschikbare kanalen - de band loopt van 610-960 MHz! -. De commerciële televisie, die in ons land ook nog eens op gang hoopt te komen, vlast natuurlijk op een aantal kanalen in die band. Een ander voordeel is, dat de antennes zo klein kunnen zijn, hetgeen het stedenschoon ten goede zal komen.Ondertussen is analoge TV opgekomen in de UHF band en weer gestaakt. Opvallend is voor mij ook dat de genoemde draaggolf frequenties niet uitgekomen zijn op latere UHF kanalen. De afstand van 5 MHz tussen de audio en video draaggolf klopt wel met de analoge TV op UHF standaarden van later. Commerciële TV via de analoge etherkanalen is er nooit gekomen, dat is heel lang tegen gehouden en later via kabel/satelliet opgekomen en pas bij de digitalisering kwam er ruimte voor digitale TV via de ether. Het deel van de UHF band gereserveerd voor TV-kanalen is ook gekrompen, ondertussen zijn we aan het werken naar een einde bij 700 MHz. Mooi om zo'n voorspelling te zien en te vergelijken met de huidige realiteit.
2017-11-13 The television version of "The Cuckoo's Egg" 2 years ago
I read the Dutch version of "The Cuckoo's Egg" when it came out in 1989. Later I bought the English version. Via a complete diversion I found out this weekend the book was made into a TV documentary: The KGB, the Computer and Me which has a lot less personal diversions than the book. It is played by Clifford Stoll himself and others involved in the original story. Although the CIA guys look a bit more stereotypical than they come out in the book. A very interesting part is there is a closing remark in the documentary by Markus Hess. Now I want to get a view of the movie of the other side, '23'. The funny part is that I found this documentary from following news related to amateur radio: Cliff Stoll -- K7TA -- Has THE KNACK. And a GREAT NOVA Video. Clifford Stoll does have a callsign: K7TA
2017-10-15 Getting to play VIC-20 games again 2 years ago
Ages ago my first homecomputer was a Commodore VIC-20. I did basic programming on it and played some games. I remember the game Centipede and loading games from audio cassette. These days games seem to be enormously complex and expensive or filled with advertisments. I don't like these, the last time I seriously invested time in a game was Pinball Dreams. I found out about the VIC-20 emulator xvic, part of the vice package. I even bought a cheap USB joystick to use. I never had a joystick with my VIC-20 so it was about time to get one. This joystick is a DragonRise Inc. Generic USB Joystick (yes, including the spaces) and I noticed today it wasn't working right: up and down on the joystick did not work. I found out eventually the left and right on the second stick mapped to up and down, thanks to a simple joystick tester from Joystick - Denialwiki in 7 lines of Basic. Some searching found DragonRise USB Driver Issue - RetroPie which mentions this issue in hid-dr.ko happened in Linux 4.4 - 4.9. I did not feel like going back to compiling my own kernels for this laptop, but there is a simple solution in Ubuntu 16.04: use hwe (hardware enablement) kernels. These seem to be aimed at the long term support server versions, but they fix my joystick problem and I can play centipede.
2017-09-01 The right to be forgotten versus keeping history 2 years ago
For ages the whole 'right to be forgotten' issue was something happening to other people for me. The worst I do on my website is name spammers that keep sending me unsollicited e-mail. This changed when I started playing with old files from BBS Koos z'n Doos including old BBS lists. A few years after I started putting these on-line I received a request to remove a name from the lists. This person advertised running a 'hardcore sex' BBS in the 1990s. But in 2013 the rather unique name of this person showed up with a decent company and in this BBS list. I could imagine that this person had no idea in the 1990s what someone might do years later with that information. At the same time it felt bad to 'change history'. Those were original files, it felt bad to change them. But after consideration I changed the name to spaces. I also received notice from the google webmaster program that some search results are hidden on bbs.idefix.net. I have no idea which ones or what names I should mask. The whole 'right to be forgotten' is a typical 'shades of gray' subject.
2016-10-05 A blast from the past! 3 years ago
I just saw:220 pi FTP server (Version wu-2.6.2(1) Mon Apr 30 20:10:54 UTC 2012) ready. 230-This is an experimental FTP server. If have any unusual problems, 230-please report them via e-mail toThat's a long time ago, the default welcome file of wu-ftpd version wu-2.6.2(1). Oh and the current default passive mode of ftp wasn't working, I had to dig up an old client to use the default active mode.
. 230- 230-If you do have problems, please try using a dash (-) as the first 230-character of your password -- this will turn off the continuation 230-messages that may be confusing your FTP client.
2016-05-27 Reminded of Computing Across America 4 years ago
A fellow radio amateur posted an old picture somewhere of Steven K. Roberts on the Behemoth "Big Electronic Human Energized Machine, Only Too Heavy" bicycle, a recumbent bicycle with computers and amateur radio as a joke suggestion to me. But this is more than just a joke to me, I follow the work by Steven K. Roberts since somewhere in the 1980s when I saw an article and picture about him in a popular science magazine. Articles and pictures by Steven K. Roberts are now collected on microship.com where some of the old memories seem to have gone the way of the 404 after almost 30 years of gathered digital history have been reorganized. Steven is still busy with the same ideas, nowadays on a nice sailboat, as can be seen at Blog - Technomadic & Gonzo Engineering with regular projects. Browsing the site I found some interesting videos such as the ones in Vintage Video: Computing Across America - Hackaday and Computing Across America - April 1988 - Louisville WHAS11 Bernson's Corner - Youtube.com.
2016-03-26 Adam Curry discovers new geek hobby, tries it immediately 4 years agoOlder news items for tag vroegah ⇒
I have been following Adam Curry on and off since the Curry & van Inkel show on the radio in the Netherlands years ago. He is a hobby pilot and active in amateur radio. Recently he heard about skywriting with gps/aprs and went all in: Digital Sky-Writing by Adam Curry and I found it on Skywriting with APRS - /r/amateurradio on reddit. Comments on reddit aren't too favourable, it is clearly a first try but I am amused by Adam's actions. Have fun, Adam.