News items for tag english - Koos van den Hout

2018-05-14 Back to the 10 meter band 2 months ago
The 10 meter amateur band (from 28.0 to 29.7 MHz) is the HF band where I started making the first HF contacts in 2014 but after that HF propagation went down and I had to go to lower frequencies and bigger antennas.

But there are short periods of better propagation and this evening I tried FT8 on the 10 meter band again and made two contacts into Norway. I even received signals from Brazil so propagation was ok, mostly along the 'greyline' which is the line over the earth between the areas in the sun and not in the sun and causes some more propagation.

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2018-05-07 I participated in the ARI International DX Contest 2 months ago
Last weekend I participated in the ARI International DX Contest.

Before the contest I was looking at the option of trying the tlf contest software and operating phone (voice) but adding the definitions for scoring this contest to tlf turned out to be not possible at the moment and at the end the weekend was filled with enough other things that only a few hours of operating RTTY were left. Propagation wasn't very cooperative and I first was blaming local interference until I noticed that the same lack of signals was showing in other places and twitter was filled with aurora pictures, so a solar flare had blocked propagation.

In the end I made 43 contacts and entered in the 'single operator RTTY low power' category. Low power on an Italian scale: below 100 watts.

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2018-05-05 High-Tech Bridge 'security scan' causing big noise in the logs 2 months ago
I noticed a lot of error messages from sshd/imaps and other services all related to IPv4 address 192.175.111.254. Checking the firewall logs found even more attempts.

It seems all this noise is related to a 'Web Server Security Test' from High-Tech Bridge. Something like the Qualys SSL Labs SSL Server Test but aimed at a complete test according to PCI DSS, HIPAA and NIST. Since most of those standards have to do with procedures too an automated test can never be complete.

But with all these errors and firewall log entries it is very noisy. And now I wonder who was interested in my webserver security at a time that I was asleep.

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2018-05-03 The preferring IPv6 policy is working 2 months ago
Yesterday I changed some IPv4 addresses on virtual machines on the new homeserver to make autofs work. This is a known issue with autofs: autofs does not appear to support IPv6 hostname lookups for NFS mounts - Debian Bug #737679 and for me the easy solution is to do NFS mounts over rfc1918 ipv4 addresses. I prefer autofs over 'fixed' NFS mounts for those filesystems that are nice to be available but aren't needed constantly.

It took about 9 hours before arpwatch on the central router noticed the new activity. I guess the policy to try to do everything over IPv6 is working.

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2018-05-01 Getting amateur satellite contacts into LoTW correctly 2 months ago
A very good bit of info just flew by on the amsat-bb mailing list: Logging Satellite QSOs with Logbook of the World - AMSAT-NA.

Complete with screenshots and needed steps, how to create an ADIF file (which I could import into CQRLOG) with the satellite-specific fields set to the values needed by LoTW to make it a valid satellite-contact.

CQRLOG has no support for satellite-specific contact information, so for me the workflow for these contacts would be to create an ADIF file as above in LoTW, upload it, and import the ADIF file in CQRLOG and not upload it from CQRLOG.

Now to find time, energy and nice weather to get on the satellites again.

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2018-04-26 More radio maps and their limits 2 months ago
The PE4KH website has maps of the locations where I contacted radio amateurs all over the world. The maps with generated images are created by exporting my locators worked/confirmed from cqrlog and using gcmwin for linux with a whole set of different configurations to plot the results.

But now the 2 meter band has been added and on that band a 'record distance' is not as far as on HF. On HF my current distance record was a contact with Australia at 16581 kilometers. My current distance record on the 2 meter band is 363 kilometer in Germany. Quite a different scale!

So the maps part has been enhanced with a 2 meter contacts map, but gcmwin can't use 6-position maidenhead locators so the map is quite coarse compared to what I want. I don't know the solution at the moment to improve this. The recent qso map PE4KH does show the more precise gridsquares when available in the log, so maybe that page needs distances added.
Read the rest of More radio maps and their limits

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2018-04-24 KVM and os-specific defaults 2 months ago
Today I wanted to install a new virtual machine on the new homeserver and virt-install gave me a new warning:
WARNING  No operating system detected, VM performance may suffer. Specify an OS with --os-variant for optimal results.
According to the virt-install manpage the --os-variant can be found with osinfo-query os which I can't find in Devuan jessie. But the same information is available via Installing Virtual Machines with virt-install, plus copy pastable distro install one-liners.

I chose debian7 as that is probably the closest to Devuan Jessie to be upgraded to Devuan ascii immediately.

The interesting change is that the resulting linux suddenly has virtio networkcards and a disk /dev/vda. That last bit is quite different from earlier virtual machines.

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2018-04-24 Building my own balun, part 7: Better measurements of the result 2 months ago
Homemade balun version 2 SWR scan 1-60 MHz
Homemade balun version 2 SWR scan 1-60 MHz 20180424
Homemade balun version 2 SWR scan 10 meter band
Homemade balun version 2 SWR scan 10 meter band 20180424
Homemade balun version 2 SWR scan 20 meter band
Homemade balun version 2 SWR scan 20 meter band 20180424
Time to do measurements of the revised attic antenna. And now with a voltage balun with more windings the balun is working better, showing ok SWR values. A nice optimum in the middle of the 20 meter band (although I originally wanted that optimum near the digital mode part) and a nice optimum in the 10 meter band (also somewhat higher than originally planned). Comparing them to the original measurements show an increase in frequency in both SWR curves.

So I consider this a good result! Time to get it on the air and make contacts again.

Next step, working on an outside dipole with the Fritzel balun.
Read the rest of Building my own balun, part 7: Better measurements of the result

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2018-04-23 Building my own balun, part 6: Redo and some success: a working antenna again 2 months ago
After the previous measurements showed the balun and dipole under the roof weren't acting as a perfect combination. So time to do a few things better: more windings, less leftover wire and a switch to a voltage balun. Yes, other sources indicate a current balun is better, but I decided otherwise. The Fritzel balun turned out to be a voltage balun after I removed it from the dipole antenna.

Balun project version 2 in case So I used the instructions at 1:1 voltage balun by VK6YSF to rebuild it as a voltage balun and I made sure the wires were shorter in the end. Getting the shorter wires in the right places in the case did get me some slightly burned fingers!

Success is currently defined as "I can transmit a carrier on the 20 meter or 10 meter band and the SWR meter of my radio only goes up a few segments" which isn't very scientific, I will need to do the rest of the measurements with the SWR meter to be sure.
Read the rest of Building my own balun, part 6: Redo and some success: a working antenna again

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2018-04-16 Building my own balun, part 5: First tests of the result 3 months ago
Homemade balun SWR scan 1-60 MHz
Homemade balun SWR scan 1-60 MHz 20180415
Homemade balun SWR scan 10 meter band
Homemade balun SWR scan 10 meter band 20180415
Homemade balun SWR scan 20 meter band
Homemade balun SWR scan 20 meter band 20180415
So I removed the old balun and installed the one I made. Removing the old one wasn't easy: the Fritzel balun has a cover over the SO239 connector which makes the heavy duty connector I used very hard to unscrew. So I had to break bits of that cover to get the needed access. And the connector ended with a lot more scratches from my attempts to get access to it.

But now the balun is replaced, and measured. And it looks like some things have changed now causing the antenna to be 'mistuned'.

Update: Just some measurements and thinking: adding the big common mode choke in the mix makes the combination show better SWR curves (still not what I want) but with the frequency with the best SWR still too low. This suggests (to me) two things: I need more windings on the ferrite core and less extra wire length from the core to the connectors. Time for a rebuild.
Read the rest of Building my own balun, part 5: First tests of the result

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2018-04-15 Building my own balun, part 4: Deciding on where to put dipole ends and finishing it 3 months ago
Balun, case and ferrite core Balun in open case I finally decided where to put the holes in the case for the dipole ends of the balun. This took some serious pondering!

I made those holes, put screws through them and wound the ferrite core with enamelled copper wire. To guess the needed length of wire I first wound it with packing rope, made a small knot at the point where it was enough and unwound the rope to measure the length I used and took a bit longer wire.

Using sanding paper I removed the enamel isolation from the ends of the wires and used soldering tin on it.

Other parts of this project:

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2018-04-08 I participated in the EA RTTY Contest 2018 3 months ago
As planned I participated in the EA RTTY Contest edition 2018.

I had most of the time to play radio on Sunday so I decided to participate in the SO20DX (single operator 20 meter band outside Spain) category. I did make two contacts on the 40 meter band when I thought I wasn't going to find any new station the 20 meter band but I returned. And found more stations on the 20 meter band.

20 meter interference pattern
Interference pattern on the 20 meter band
Radio propagation was ok, best DX were some Asiatic Russia stations and a US station in Illinois. The local noise was bad and there were some new sources of interference active. The pattern as in the image (links to full view of the 2.5 kHz waterfall) which is very stable in frequency and has a tendency to stop and start, and at the stop the carriers move together. Also a more 'rattling' noise which sounded like an electrical problem.

In the end I made 81 contacts in total, 79 on the 20 meter band.
Read the rest of I participated in the EA RTTY Contest 2018

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2018-04-07 I'm glad you read my newsitem 3 months ago
Apr  6 23:41:16 greenblatt sshd[25116]: Invalid user squid from 139.99.122.129
Apr  7 01:44:09 greenblatt sshd[3495]: Invalid user squid from 110.10.189.108
Apr  7 08:21:37 greenblatt sshd[7106]: Invalid user squid from 118.24.100.11
I'm glad you read my newsitem about keeping squid running.

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2018-04-06 And a contact with South Africa, new country 3 months ago
Another new country that should not be too hard to get in the log but did not happen until today: South Africa. ZS6ZA was active on 40 meter FT8 and received my answers.

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2018-04-06 25 years of Linux use 3 months ago
Powered by Linux 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 (if I recall correctly) of Hogeschool Utrecht with SLS Linux.

Anyway, still using Linux a lot. It's been an interesting 25 years!

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2018-04-04 I am planning to participate in the EA RTTY Contest 3 months ago
After my participation in the EA PSK63 Contest 2018 I plan to have the radio active in the upcoming weekend for the EA RTTY Contest.

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2018-04-04 Building my own balun, part 3: First work on the case 3 months ago
Balun project case Balun project case The first work on the balun case was placing the SO239 socket. This included drilling a hole in the case of the right size and at the right position. Figuring out where to put it was mostly influenced by the fact that the ferrite core has to be placed inside the case and I wanted the SO239 socket, the ferrite core and the output terminals not all jammed together. So the SO239 socket was not going to be in the center. For this my new caliper was a useful tool and I measured the inside size and the wanted location of the socket. And I figured out I could drill a 16mm hole and the SO239 socket would fit inside while leaving enough room for the mounting flange.

Holes were drilled and things worked out fine, so the SO239 socket is now mounted. After checking the future location I realized I will have to mount the balun with the SO239 socket facing downwards because the antenna cable is quite heavy. This has to be taken into account with the next steps.

Other parts of this project:

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2018-04-04 Building my own balun, part 2: measuring the 'old' balun 3 months ago
Fritzel balun SWR scan 1-60 MHz 20180325
Fritzel balun SWR scan 1-60 MHz 20180325
Fritzel balun SWR scan 10 meter band 20180325
Fritzel balun SWR scan 10 meter band 20180325
Fritzel balun SWR scan 20 meter band 20180325
Fritzel balun SWR scan 20 meter band 20180325
Since I want to replace a balun that has been up there for ages I want to be able to compare the two. So I used the antenna analyzer to get graphs of the SWR over the whole possible range (1-60 MHz) and on the amateur bands it was built for: the 10 meter band and the 20 meter band.

There was a very interesting difference with the earlier results on the 10 meter band when I first tested the SARK100 antenna analyzer from Linux. The 10 meter band dipole probably moved a bit or something else changed.
Read the rest of Building my own balun, part 2: measuring the 'old' balun

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2018-03-30 More FT8 on the 2 meter band 3 months ago
I have now tried FT8 on the 2 meter band several times. One time I received a message via FT8 to try it on the 70cm band too but I haven't figured out the right frequency on that band yet.

DX contacts have been made into England, France and Germany. Furthest 2 meter contact at the moment is 323 kilometers. From the doppler shift I see the most probably reason for these distances is aircraft scatter, which means I'm using big metal reflectors in the sky to bounce my signal, without even paying for an airplane ticket.

I'm looking forward to 'E-skip' and other phenomena that can make 2 meter radio signals reach larger distances. I wonder what that will bring me.

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2018-03-24 Trying FT8 on the 2 meter band 3 months ago
The different radio bands also have quite different properties. The HF bands below 30 MHz have ionospheric refraction which lets the signal return to earth in far away places. The VHF bands (30-300 MHz) are usually only line of sight, signals usually will not get beyond the horizon.

Recently I saw mention of the FT8 mode on the 2 meter band. Specifically here: Essex 2M Activity Day Update - Essex Ham and VHF FT8 - M1AVV.

This inspired me to give it a try myself. It took a bit of searching to find the right frequency for FT8 on 2 meter. I found out it's 144.178 MHz so I started trying there and soon made my first contacts with Dutch amateurs at reasonable distances. But from time to time I saw signals from further away than was possible, for example England and France. My best guess is that aircrafts reflect the signals. I also saw doppler shift in signals which confirms aircraft reflections.

After a few tries I was able to make my first contacts at nice distances in the Netherlands.

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