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Koos van den Hout

Welcome. This is my homepage where I write about my opinion, projects, things I note, things I try and other random stuff. Newsitems have tags for a bit of structure.

Latest news/thoughts/geeking/rants/notablog

2016-12-05 NL-Alert? Doe mij voorlopig ook maar een echt luchtalarm 12 hours ago
Vandaag was weer een NL-Alert controlebericht en als ik zo de geschiedenis inkijk van ontvangen infoberichten op mijn telefoontoestel denk ik dat het voorlopig niet verstandig is het 'ouderwetse' luchtalarm uit te schakelen.

Ik heb een dual-sim telefoon, die op de netwerken van Vodafone en T-mobile zit. Dus in theorie krijg ik 2 keer per jaar 2 berichten.

Uit de huidige geschiedenis:
  • 2015-12-07 12:00: om 12:01 ontvangen via t-mobile
  • 2016-06-06 12:00: niets ontvangen
  • 2016-12-05 12:00: om 12:03 ontvangen via vodafone
Op 2016-06-27 was er een echte reden tot nl-alert, en die heb ik via vodafone ontvangen.

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2016-11-27 Finished the homebrewed QYT KT-8900 programming cable 1 week ago
Homebrewed QYT KT-8900 programming cable, CC-BY-SA
Homebrewed QYT KT-8900 programming cable
I finished the homebrewed QYT KT-8900 programming cable by using tiewraps to clamp the two pieces of cable together and using heatshring tube to cover the wires and pack it all together.

More about Creating the homebrewed QYT KT-8900 programming cable and instructions for building a 3-pin programming cable for QYT/BTech/others and the KT-8900 FAQ at Mikklor.com.

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2016-11-24 Creating a programming cable for a QYT KT-8900 with some soldering 1 week ago
QYT KT-8900 radio with homebrewed interface cable, CC-BY-SA
QYT KT-8900 radio with homebrewed interface cable, CC-BY-SA
I bought a cheap 2m/70cm mobile/base radio, a QYT KT-8900 which has the special feature of being very small but still able of putting out 25 Watt on the 2 meter VHF band and 20 Watt on the 70 centimeter UHF band.

The display looks a lot like my Wouxun KG-UVD1P, complete with battery status indicator which is not much use when the radio has a constant 13.8V feed. The menus are quite similar, so this is probably not a coincidence.

I bought it via aliexpress and it got shipped at a reasonable speed to my house. In the original listing was mention of a programming cable, but it showed up without one. I asked the seller about this and directly a baofeng programming cable was shipped to me.

But, the QYT KT-8900 has a different programming interface, just a 3.5 millimeter plug with ground, rx and tx data. So I found a very good resource for chinese radios which has the answers: 3 PIN Programming Cable for a BTech, QYT, etc Mobile which has the right pinout. I just cut the Baofeng cable to get at the gnd, rx and tx wires.

Next I had to wait for a cable with the right 3.5mm connector to show up. The connector in the back is sunk into the case and the 3.5mm connectors I had in the junkbox did not fit. But a broken PC speaker set wanted to donate a cable with 3.5mm connectors that were slim enough. Next trying the result with chirp radio programming software under Linux. And suddenly I could copy a list of channels I had and upload it to the radio in 5 minutes, which is a lot faster than manual programming where getting more than one channel programmed in correctly under 5 minutes is hard, see for example Programming Repeaters into the QYT KT8900 Mini Dual Band Mobile Radio Review - AF5DN - Youtube.

At the moment the cable looks very experimental. Now it has been tested I will use tiewraps and heatshrink tube to make it sturdier and make it look a lot better.

As a radio it's ok, but not ideal. I was testing with meetnetwerk baretta - hobbyscoop and the antenna on the roof for 2 meter and 70 centimeter and noticed I had pulsing audio of the output frequency of PI2NOS on the Baretta frequency. Pulsing audio is a known problem in this radio, see KT8900 FAQ at miklor.com but I have no channels with receive CTCSS.

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2016-11-24 (An error message I just saw in my browser. And no, I did not select 'view intimate technical details...) 1 week ago
Google+Koos van den Hout : An error message I just saw in my browser. And no, I did not select 'view intimate technical details'.

A PKCS #11 module returned CKR_DEVICE_ERROR, indicating that a problem has occurred with the token or slot. Error code: SEC_ERROR_PKCS11_DEVICE_ERROR

This is not 'making security easy'.
2016-11-22 A bit of hope for radio contacts 1 week ago
Recently getting some new contacts on amateur radio has been very difficult. And news articles like Sunspot cycle plunges to lowest level in 5 years - Southgate arc which points at source Sunspot cycle at lowest level in 5 years - spaceweather.com tell us things aren't going to improve soon.

But sometimes interesting radio contacts are possible. Last Friday I complained somewhere about propagation being down and the next morning I saw a reply that propagation had improved after 23:00, by which time I was asleep. Yesterday evening I had some time to try the radio after 21:30 and I first added Albania to the list of countries I contacted with a PSK31 contact on 40 meters with ZA5G and later I even had a voice contact with RA3QK who gave me an S5 report.

I kept scanning around the band and heard pileups for some popular stations from the Brazil and the US, who never heard my answer. And later I heard an active net on 7178 kHz with a number of US and Canada stations active. I tried breaking in but they also could not decode my callsign. One of the active members in that net was WA3RSL whose qrz page clearly shows he is a big 40 meter fan and has the space for huge antennas.

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2016-11-20 Ik heb mee proberen te doen aan een contest.. en geen contacten gemaakt 2 weeks ago
Friese vlag van Wikimedia commons, CC-BY-SA
Frisian flag, wikimedia commons, CC-BY-SA
Vandaag heb ik geprobeerd mee te doen aan de Friese elfstedencontest 2016 (waarschuwing: pagina met comic sans) en heb in totaal nul (0) contacten gemaakt in die contest. Ik had de hele opstelling al zaterdag gereed gemaakt: endfed antenne naar buiten, headset interface aan de radio, separator kit aan de radio. En ik had tijd gestoken in aanpassingen aan yfktest zodat het het logging formaat voor deze contest snapte.

Deze contest is tussen 11:00 en 14:00 lokale tijd, en ik kon pas later beginnen door andere afspraken. En als ik zo de berichten lees bij Friese 11 steden contest 2016 - zendamateur.com was de meeste kans om nog ergens contact mee te maken in het eerste uur.

Ik heb een roepend station gevonden dankzij de dx-cluster, maar ook die hoorde mijn antwoorden niet.

De ernstig tegenwerkende factor was de slechte NVIS propagatie (radiosignalen wilden niet tegen de ionosfeer recht naar beneden reflecteren). Volgende keer beter natuurlijk, volgens berichtgeving zijn we bij het dieptepunt van de zonnevlekkencyclus en kan het met een paar jaar dus weer beter worden.

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2016-11-18 Trying to scam the spammed 2 weeks ago
An interesting scam mail received in several of my inboxes:
To: abuse@...
Subject: you've been scammed

Your email abuse@... has been hacked and spam is sent to all your contacts!
If you don't have a lawyer, you may contact me at mark.silberman78@gmail.com

Best Regards,
Mark
I guess 'Mark' bought the cheapest available list of spammable addresses and is now trying to profit from the people spammed.

The other variation is with
Subject: You are hacked!
But with everything else exactly the same.

Update: I am getting some responses to this post, other people are seeing this spam too. I guess I was just the first one to write a post about it, since I usually like to link to posts showing I am not the only one. Hello visitors puzzling about this spam!

Update II: It's not just me! Also noted at You are hacked or scammed - hoax.co

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2016-11-17 De zoektocht naar niet-storende LED lampen 2 weeks ago
In onze keuken hadden we 5 spotjes met halogeen lampjes achter een dimmer om zo op het werkblad goed licht te hebben. Toen kort na elkaar 2 van die lampjes stukgingen was de conclusie dat er binnenkort wel meer stuk zouden gaan en dat dit een mooi moment was om aan LED lampen te beginnen.

Ondertussen zijn er dimbare LED lampen die ook halogeen spotjes kunnen vervangen. Alleen was de gedachte in mijn achterhoofd natuurlijk of ze dat ook kunnen zonder radiostoring op te leveren.

In de Electron, het verenigingsblad van de Veron heeft recent een stukje gestaan van een radio amateur die na eerdere storingen geen storing meer had na het vervangen van goedkope LED lampen door Philips LED lampen. Ik heb het er dus op gewaagd en 5 philips LED lampen gekocht, type LED Spot 8718696483824 van Philips, GU10 fitting, 4W (vervangt 35W) dimbaar, warm wit.

Het licht is inderdaad serieus anders dan van halogeen lampen, dus ze alle 5 tegelijk vervangen was een goed idee. En de storing is minimaal, pas als ik heel dichtbij kom met een kortegolfontvanger krijg ik een storing binnen die net zo goed via de electriciteitsdraden kan komen.

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2016-11-12 Disabling IPv4 on the Raspberry Pi 3 weeks ago
I have two Raspberry Pi's running in the house, currently with IPv4 still enabled on them. They both run Raspbian 8.0. I was wondering whether I can disable IPv4 on the Raspberry Pi, but a google search does not yield very helpful answers, most of the search terms I try still find pages about disabling IPv6. I want to disable the legacy IP protocol.

Only one way to find out: go for it. Now rebooting one with the statement ipv6only in /etc/dhcpcd.conf.

First thing I noticed was that the searchdomain was not set in /etc/resolv.conf which was indeed only available via the DHCP process for IPv4. So now radvd advertises the search domain via the DNSSL option in /etc/radvd.conf:
   RDNSS 2001:980:14ca:42::18 {
   };
   DNSSL idefix.net {
   };
The first results are:
  • It turned out the ntp config on the raspberry had one IPv6-only and one IPv4-only server. Added a dual-stack server.
  • And ndpmon really does not like the DNSSL option, even when I add it in the config_ndpmon.xml file as
                      <dnssl>
                        <domain lifetime="600">idefix.net</domain>
                      </dnssl>
    
    Fixed by changing it to
                      <dnssl>
                        <domain lifetime="600">^Fidefix^Cnet</domain>
                      </dnssl>
    
    yes, with literal ctrl-F and ctrl-C characters, showing that there is some error in the parsing somewhere.
  • rwhod is IPv4-only so the status is not visible in my network anymore. A workaround for that is not disabling IPv4 completely but just removing the default route, not using ipv6only in /etc/dhcpcd.conf but using the option nooption routers.

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2016-11-12 Sofar, cloud backup is not a resounding success 3 weeks ago
So the first few tries of a backup to a remote webdav filesystem using amanda have been done.

The result is that the davfs2 filesystem driver is very I/O intensive when writing to the local cache. The fact that amanda creates 2 gigabyte files (actually compressed tar archives) also makes the caching of davfs2 use quite a high amount of diskspace. Eventually things get flushed to the remote filesystem and this fills the uplink completely. During this I/O intensive period certain things are very slow, for example the df command. The running webserver is still fast enough.

It's easy to calculate that it takes a while at 20 megabit to upload a few gigabytes, but it seems clear that this needs a bit more work before I can replace the tape backups. There is also the interesting chicken and egg problem of how to restore from scratch.

2016-11-12 (Bus in Amsterdam running Windows XP on the advertising and information screen. Noticed on the return...) 3 weeks ago
Google+Koos van den Hout : Bus in Amsterdam running Windows XP on the advertising and information screen. Noticed on the return trip from the O'Reilly security conference.
2016-11-11 DAB services scan 11 November 2016 3 weeks ago
DAB+ logo En dit keer wel DAB multiplexen ontvangen die eigenlijk te ver weg zijn, zoals MTVNL Noord-Limburg/Noord-Brabant op 9C. Die is zelfs bijna storingsvrij, multiplexen op 6B en 7A worden wel gezien in de scan maar geven geen geluid wegens teveel fouten.

NPO is voor de hoofddiensten (Radio 1 en andere diensten die ook via de FM beschikbaar zijn) overgegaan op betere foutcorrectie (EEP 3-A in plaats van eerder EEP 3-B). Dit was een enorme klacht bij de overgang van de NPO multiplex van DAB op DAB+ in 2013, de foutcorrectie bij de NPO werd minder wat ontvangst aan de rand van de dekkingsgebieden moeilijker maakte.
Read the rest of DAB services scan 11 November 2016

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2016-11-10 Backup to .. the cloud! 3 weeks ago
So I now have some cloudstorage space available also via webdav and I am working on using this for backups. The main idea is to have a daily backup to the cloud service and do the tape backups less often.

I still want incremental backups so I can go back to specific older versions of files. So I want to use amanda for backups. I installed the davfs2 package to be able to mount the webdav filesystem and access it from Linux. The first few clues come from Set Up Virtual Tapes - Amanda Howto but I had to switch to the chg-multi driver as described in Backup to Virtual Tapes on a non-UNIX Filesystem - Amanda Howto because the webdav filesystem does not support symlinks.

I/O performance during the backup isn't ideal and the vdsl uplink is completely full during the filetransfer. Maybe I need to slow down the backup process a bit and ratelimit the webdav transfer.

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2016-11-10 (A new amateur radio satellite to play with. One with a limited power budget, so availability will be...) 3 weeks ago
Google+Koos van den Hout : A new amateur radio satellite to play with. One with a limited power budget, so availability will be an issue.
Also, make sure you don't use more power than needed so the transponder is available for everyone and the power use is minimal.
2016-11-07 The future of the Internet is IPv6 4 weeks ago
Just read Internet Architecture Board Statement on IPv6 with:
The IAB expects that the IETF will stop requiring IPv4 compatibility in new or extended protocols. Future IETF protocol work will then optimize for and depend on IPv6.

Preparation for this transition requires ensuring that many different environments are capable of operating completely on IPv6 without being dependent on IPv4 [see RFC 6540]. We recommend that all networking standards assume the use of IPv6, and be written so they do not require IPv4. We recommend that existing standards be reviewed to ensure they will work with IPv6, and use IPv6 examples. Backward connectivity to IPv4, via dual-stack or a transition technology, will be needed for some time.

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2016-11-06 One source of interference found: osram halotronic htm 70 transformers 4 weeks ago
Recently I noticed one source of radio interference on 40 meter was the lighting in our bathroom. There are two sets of lights in the bathroom, one with a switch which causes heavy interference and one with a dimmer.

The lights in the bathroom are all 12volt based and the transformers are in a weird corner above the bathroom, but accessible for me. So I found out the "osram halotronic htm 70" electronic transformers (the specs read like switching power supplies) are quite audible on the 40 meter band. The other two a lot less than the switched one. Time to complain to Osram and/or replace them. The Osram Halotronic HTM 70 specifications at Osram say the maximum length of the wire after the transformer is 2 meters to keep RF interference below acceptible levels, I am not completely sure the complete wires until the lamps are shorter than that, so it may also be an installation fault.

Searching for "osram halotronic htm 70 interference" finds this interesting bit: Installation LED Leuchten in Spanndecke with:
Aber auch wenn "nur" der Meßwagen der Bundesnetzagentur vorbeikommt und Deine Konstruktion kostenpflichtig stillegt, kommt wenig Freude auf.
The German Bundesnetzagentur is a lot stricter in finding and stopping interference to amateur bands.

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The person

Father, cat owned/owner, Unix/Linux fan, Internet user, reader, recumbent byciclist, snowboarder, ipv6 fan. For those who don't speak Dutch: how to pronounce Koos van den Hout.

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Specialist information security at Utrecht University with a modern Profile page.
 

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Koos van den Hout, reachable as koos+website@idefix.net. PGP encrypted e-mail preferred.

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Meningen zijn die van mezelf, wat ik schrijf is beschermd door auteursrecht. Sommige publicaties bevatten een expliciete vermelding dat ze ongevraagd gedeeld mogen worden.
My opinions are my own, what I write is protected by copyrights. Some publications contain an explicit license statement which allows sharing without asking permission.
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