News items for tag hamradio - Koos van den Hout

2017-04-24 Somewhat less HF interference by moving the antenna away 2 days ago
I was testing with noise on all radio bands with the LW-10 longwire antenna with tuner. I recently made the rope that hangs it out from the window a bit longer and I noticed the noise on the 10 meter amateur radio band had dropped a lot compared to the noise I experienced before and the noise on the antenna under our roof. In S-points: under the roof S8, with the 10/20/40m endfed S8, and with the longwire antenna S0.

On bands with lower frequencies (higher wavelengths) noiselevels were high, up to S9+ on 80m with a rattling noise in it. But this sudden change on the 10 meter band made me think there could be a pattern so I measured how much more distance I could move the antenna away from the house and maybe get lower noise levels on the 20m band too. After adding 1.60 meter of rope and rehanging the antenna the noise level on the 20 meter band also dropped from S8 to S7. Not the biggest improvement but it's something.

I'm now making some PSK qso's on the 20 meter band. At the S8 noise level this was getting impossible.

Tags: ,
2017-04-23 Going full duplex with amateur satellites, part 7 : Recording downlink audio 3 days ago
This evening I thought there would be a nice Fox-1A (AO-85) pass but gpredict on another computer showed totally different predictions. Pondering that difference made me suddenly remember AO-85 is still not part of the 'standard' set of Kepler data because it's close to some militairy satellite. The data is available through other sources, I use TLE | Amateur radio PE0SAT and updated from that location. The 'nice' AO-85 pass near 22:30 localtime shifted to 'way too late', so I looked for other satellites to at least try recording downlink audio. I saw passes of HO-68 and UO-11. So I created the whole setup with audacity recording audio. Using pavucontrol I adjusted the recording flow of audacity to record 'Monitor of Built-in Audio Analog Stereo' and indeed audacity was recording the same as I heard on my headphones.

But no signal from the satellites was received. Checking the Amsat Oscar status page shows both haven't been heard by others either. So I recorded noise, but I recorded the right noise.

Tags: , , ,
2017-04-23 New band in amateur radio: 60 meters (5 MHz) 3 days ago
Today I was scanning the bands to build an overview of noise / interference levels on each band and I came across the 60 meter band (5 MHz) which I can get tuned on my LW-10 longwire antenna. No idea how much power is eaten by the tuner and how much gets out but it works. I noticed some RTTY signals and those were within the part of the band I can access with my license.

So I answered the CQ from DK7UY and we had a good contact.

The 60 meter band is a recent addition for Dutch and other amateurs, only allowed since 3 december 2015. Around that date the WRC-15 conference happened where world-wide agreements were made about secondary amateur access to this band. And on 1 april 2017 the access for Dutch amateurs was limited to the agreed allocation.

Tags: ,
2017-04-22 Going full duplex with amateur satellites, part 6 : First succes in reception 4 days ago
Today I had time for a reception test and when I started collecting the amateur satellite reception gear I saw two upcoming passes, one of the AO-73 Funcube and one of the AO-85 Fox-1a satellite.

The AO-73 Funcube is an 'inverting transponder' which converts an LSB uplink to an USB downlink with space for multiple contacts at the same time. By default gpredict selects the center frequency where I heard PA3HDG calling CQ but hearing no answer. Sorry, I did not have the rest of the setup to transmit that answer.

The AO-85 Fox-1a is like an FM repeater in space so it should be easier to receive it. But I heard nothing, which was most likely due to the satellite being in a part of the sky where the hedge is in the way. was due to the fact my data about that satellite wasn't updated: it's not in the default sets. Updating from a trusted source of extra kepler data TLE | Amateur radio PE0SAT showed a shift in pass times of more than 60 minutes.

Anyway, first success in reception. Next steps: recording the received audio with audacity and adding the transmitter to the mix to be able to make actual contacts. At least the concept I imagined with the rtl-sdr stick as receiver so I can work full-duplex works.

Tags: , ,
2017-04-14 Going full duplex with amateur satellites, part 5 : first test of the amplifier with RTL-SDR 1 week ago
For a first test I looked for the first reasonable pass of an amateur satellite and tried to recieve the morse beacon of HO-68. I have received signals from HO-68 before, but this pass I heard nothing.

I tried a stable regular local source on the 70cm band : the PI2NOS repeater and noticed after a while the frequency display in Gqrx was showing 430.100 MHz where the (GPS stablized) frequency is 430.125 MHz, so the RTL-SDR I use is somewhat off frequency. Maybe in a next test things work better.

Tags: , , ,
2017-04-14 Going full duplex with amateur satellites, part 4 : amplifier built into the case 1 week ago
Today I had some time to work on the metal case for the amplifier I bought for receiving amateur satellites. I've never been good at metalwork but I think I did ok. First I made sure the place I wanted to put the holes was chosen correctly, taking the size of connectors into account. Especially with metalwork it's "measure twice, cut once". Next I drilled holes with a drill for metalwork (HSS) and used a file for metalwork to make the holes bigger. I visited the local electronics shop to get a small switch for switching the battery power on and off and added a hole for the switch. In the end the amplifier and the cables are mounted inside the case and there is a bnc connector for the Arrow antenna on one side and an SMA connector for the cable to the RTL-SDR stick on the other side.

Battery added for amplifier in metal case - KvdHout on FlickrBattery added for amplifier in metal case

Tags: , , , ,
2017-04-12 Trying the mini-whip as reception antenna 2 weeks ago
Recently I talked to a fellow radio amateur about my HF reception woes at home and he suggested trying the mini-whip antenna I built a few years ago as reception antenna, using an automatic switch to switch between the transmission and reception antenna.

For the first test I used the mini-whip antenna with the HF downconvertor and an RTL-SDR stick that I bought to receive amateur satellites to check the signal on the computer. The further I move away from the house the better signal I get (less noise, more signals sounding like the amateur radio signals I want). I do notice that when I turn the gain on the RTL-SDR up (or set it to automatic gain) that there is a repeating 'ticking' signal which sounds just like the ticking interference from my own PLC tests.

This could mean that a nearby neighbour has a PLC network without the notches for amateur radio. Or this is just an artefact of the high gain.

Tags: , ,
2017-04-10 Amateur radio callsign lookup on Android without needing Internet access 2 weeks ago
Earlier I had the Android application Ham Radio Prefixes - Android Apps on Google Play installed, but it needs some server on the Internet to look up callsigns and determine the country it is assigned to. Sometimes I need to do a lookup off-line, and I noticed fldigi and CQRLOG do that fine when the country data file is installed. So it can be done, I just have to find software that does this right.

On ICQ Podcast Episode 234 - Portable Power Distribution and I heard mention of Pocket Prefix for Android which can be found at Pocket Prefix - Android Apps on Google Play and which works off-line. This was even mentioned on the podcast as one of the advantages. It even gives extra information when available, the given example is that prefix SV is for Greece but SV9 is specific to Crete. Or EA9 is specific to the Spanish enclaves Ceuta and Melilla which are located in Morroco (and therefore count as a contact with the African continent).

It's a nice application, thanks to Derek Turner G4SWY!

Tags: , , ,
2017-04-06 Results from a powerfailure 2 weeks ago
Earlier today there was a local powerfailure. I noticed it while being connected remotely to my server at home, it stopped responding and stayed off-line for a while. I checked the website of the electricity distribution network and it showed a local powerfailure.

Initially my reaction was a bit of interest in how low the radio noise levels would be when I could try the radio at home. By the time I got home power was back on so I never found out.

Some systems at home had to be started by hand, but eventually everything was up and running again, with new kernels booted. Everything came up fine including PPPoE to the outside world.

Later in the evening I noticed the old weatherstation in the shed which measures the temperature and humidity inside the shed seemed inoperational. Checking that weatherstation eventually led to a diagnoses that the 12 volt powersupply for that weatherstation had failed. It was only delivering 7.2 volt. To disconnect that weatherstation for diagnosis I completely shut down the shed computer ritchie. After that it did not come up again. Power came up and the harddisk started spinning but nothing happened after that.

So I also took that computer in for diagnosis. Connected to a keyboard and monitor everything came up fine. Disconnected from the monitor nothing came up.

Slowly it dawned on me that this might be related to an issue which I had read on the PC Engines Alix.1d page :
BIOS update

* beta various updates (release MFGPT timers)
* beta fix VGA DDC issue (boot hang)
Which seemed to be the problem which suddenly started acting up for me which it never did before. But the BIOS clock was also reset so I guess the whole setup was erased and I just did not notice because the default settings were good enough to boot anyway and ntpd sets the clock soon after boot. A simple solution would be a BIOS upgrade.

But preparing a CF card to boot freedos seemed a long way to flash the bios so I tried it via the Heavy Duty Boot pxeboot environment which booted FreeDOS nicely on the alix.1c but it rebooted as soon as I started SB.COM. I guess sb.com searches for bios images on C:\ and the FreeDOS floppy image is A:\

In the end I searched for a workaround and found mention in PC hangs up when no monitor attached - Ubuntu bug #243257 of a wire between pins 12 and 7 in the VGA connector. A piece of wire was bent and inserted into the vga connector and now the weatherstation computer ritchie boots up again.

Next plan is to do the BIOS upgrade via flashrom: In searching for information about the Alix 1.c bios upgrade I'd like to do I came across mention of flashrom.

Tags: , , ,
2017-04-03 I participated in the EA RTTY contest 2017 3 weeks ago
This weekend after the antenna installation was done I had some time to participate in the EA RTTY contest 2017. I only participated on Sunday afternoon on the 20 meter band so I entered in the SO20 DX category.

The end result was 35 QSO's (contacts). Less than the results I had in the EA RTTY contest in 2016 but I had less time and energy available.

Tags: , ,
2017-04-02 Antenna for 2m/70cm up on the dormer roof 3 weeks ago
Antenna mounted on dormer roof
Antenna for 2m/70cm, Diamond X-30N, mounted on roof of dormer
Parts for mounting the Diamond X-30N which I bought in October on the roof were collected in the months since October and it was finally clear enough weather for a fellow radio amateur with lots more climbing experience and the right gear to climb on top of our dormer and install it.

There are rubber granulate pads on the roof to avoid damage, a metal frame sold as a mount for satellite dishes to which the antenna is mounted, 4 concrete tiles in the mount to weigh it down on the roof. The coax enters the house alongside a chimney.

After the work on the roof it was good to drink a beer to celebrate and afterwards I routed the cable further to my shack.

The first fast test was calling CQ on a local 2 meter frequency and someone from my radio club answered immediately.

The second big test was participating in a radio roundtable held on Sunday evening. This went fine, net control at a distance of somewhat over 30 kilometers gave me a 55 report (audio readability 5 and signal level 5). So the antenna is clearly doing what it is supposed to do. It's also nice to see the base noise level on the 2 meter band is near zero.

Tags: , ,
2017-03-29 Going full duplex with amateur satellites, part 3 : metal cases 4 weeks ago
I was looking for a metal case to put the low(ish) noise amplifier in and maybe the RTL-SDR. The RTL-SDR should also be shielded from the amplifier and from the computer as both RTL-SDR and computer cause their own signals.

The first cheap source of metal cases I could think of was old cigar boxes. Altoid tins are not available here. So I asked someone who I know who smokes cigars who had a number of old metal cigar boxes. Next step, finding the way to get the right holes in the boxes for the SMA and BNC connectors, and for the USB connection to the computer. Ideal would be to lend / find a punch for those holes.

Tags: , , ,
2017-03-27 Upgrading WSJT-X after hearing two words 1 month ago
Recently it seems radio noise levels on the HF bands have gone up again so I spend more time trying to make contacts in JT65 mode since that mode is more robust against noise than PSK31.

To do this I use the WSJT-X software under Ubuntu Linux. WSJT-X is written by Joe Taylor KJ1T. The Ubuntu hams packages had WSJT-X 1.1 and I frequently ran across the problem that it crashes when the Internet connection to pskreporter is impossible when sending spots. In my setup the Internet connection drops regularly when I'm active with JT65 or PSK31 so that was an annoyance. Logged as Ubuntu bug #1673040: wsjtx crashes when internet connection is interrupted.

But this weekend I was listening to Linux in the Ham Shack Episode #184 and in the presenters talking about re-installing a Linux system for amateur radio I heard two words: wsjtx ppa. As soon as possible I looked it up and found WSJTX General Availability Release PPA, followed the installation instructions and upgraded to WSJT-X 1.7.

The main improvement is that it decodes better so I may make further contacts. Sofar it hasn't crashed on an interrupted Internet connection.

I see one problem: it doesn't like talking to my radio via rigctld, giving an error. When I stop rigctld as started by Cqrlog and let WSJT-X control the radio directly via hamlib things work fine. And suddenly Cqrlog sees the QSO in progress and logs it when done.

Tags: , , ,
2017-03-26 Going full duplex with amateur satellites, part 2 : Installing Gqrx SDR software and the first tests 1 month ago
With the hardware available it's now time to test the first part of the software setup: whether I can have running software defined radio.

To (re)install Gqrx I followed the instructions at Install Gqrx SDR on Ubuntu Linux. The first 'sudo apt-get purge --auto-remove' steps removed a lot of software and the latter 'sudo apt-get install' steps added newer (or maybe the same) versions. But I was glad to do a full reinstall, I have had weird problems with gqrx versions before. The laptop on which I am doing this has had an install of gqrx before, but was upgraded from Ubuntu 14.04 LTS to Ubuntu 16.04 LTS in the mean time, so a clean reinstall seemed a good idea.

I plugged in the RTL-SDR stick and checked whether no drivers were installed, which was indeed still correct. The kernel messages:
[156490.915435] usb 2-2: new high-speed USB device number 7 using xhci_hcd
[156491.111136] usb 2-2: New USB device found, idVendor=0bda, idProduct=2838
[156491.111141] usb 2-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[156491.111143] usb 2-2: Product: RTL2838UHIDIR
[156491.111145] usb 2-2: Manufacturer: Realtek
[156491.111147] usb 2-2: SerialNumber: 00000001
To make sure the drivers aren't loaded, I have a /etc/modprobe.d/local-blacklist.conf with:
blacklist dvb_usb_rtl28xxu
blacklist rtl2830
blacklist rtl2832
blacklist lirc_dev
To test it with the 'minimal' setup I started with just the RTL-SDR and a simple antenna, and Gqrx. Enabled remote control in Gqrx and added a radio 'gqrx-sdr' in Gpredict with host 'localhost' and port '7356' (default for gqrx remote control) and Radio type 'RX only', PTT status 'none'.

Gqrx controlled by gpredict
Gqrx controlled by Gpredict, tracking a satellite
Now I can select this radio as '1. Device' in the 'Gpredict Radio Control' window, and select 'Engage' when the right satellite, transponder and 'Track' are selected, after which Gqrx nicely follows the frequency Gpredict has calculated.

No signal yet as I am testing this indoors with the small default antenna that came with the RTL-SDR stick. That will not pick up weak signals!

Tags: , , ,
2017-03-26 Going full-duplex with amateur satellites, part 1: introduction and I bought the hardware 1 month ago
I still want to get active on amateur satellites again, but the main reason is that the amount of work per contact is a lot more than for example in a digimode contest. But I still want to make those 'special' contacts, especially when the amount of local radio noise on HF is bothering me.

One of the most important improvements in making contacts on amateur satellites is working 'full duplex', meaning receiving signals while transmitting. The expensive way to reach that goal is buying a second amateur radio capable of receiving in FM and SSB modes in the 2 meter and 70 centimeter amateur bands and having computer aided tuning so gpredict can control the receiving frequency.

The less expensive way to reach that goal is using software defined radio. The good news is that Gqrx SDR can be controlled by other software which as the page shows is intended for remote control by Gpredict. All I needed now was reception hardware. Since the first RTL-SDR device I bought is always in use for receiving ADS-B signals from airplanes I decided to buy another cheap one to get me started. So it was on the shopping list for a recent visit to a hamfest.

At the hamfest I found a RTL-SDR stick with mcx connector and an mcx to bnc cable. But the same guy also sold cheap low(ish) noise amplifiers with SMA connectors and a 9V battery connector for power. So at one of the booths selling cable assemblies I found an mcx to male sma cable and a female sma to bnc cable, and a male to male sma cable.

The plan is to put this all together in some metal case to shield the lna from the outside world. Maybe also shield the amplifier from the RTL-SDR stick so it won't pick up any extra noise.

Should this work it would be possible to think of an upgrade with better SDR hardware and/or a pre-amplifier at the antenna side.
RTL-SDR stick and BNC cable - KvdHout on FlickrRTL-SDR stick and BNC cable
LNA and extra cables - KvdHout on FlickrLNA and extra cables
Read the rest of Going full-duplex with amateur satellites, part 1: introduction and I bought the hardware

Tags: , , ,
2017-03-05 Back from a short holiday where I was active with amateur radio 1 month ago
We stayed in a holiday park in Germany for 6 days and I decided to bring radio, tuner and the 6-40m antenna. So I was DL/PE4KH for a week and operated PSK modes a few times.

In total I made 11 contacts. The 'radio environment' was about as noisy as I am used to at home so no improvement there. Disconnecting the power supply for the television and the cable modem in the bungalow helped a bit in reducing the radio noise.

The interesting part was on Thursday evening when I only heard noise on the 40 meter band and decided to give 80 meter a try. It was active with PSK signals, including from callsigns I recognize as regulars on 20 and 40 meter PSK. My best guess is that 40 meters was unavailable for others too! The interesting part was that the antenna tuner was able to tune the LW-10 antenna for 80 meter. I do guess a lot of power was lost in the tuner as I only was able to make contacts with stations that came in very strong for me.

For the next time:
  • Make sure fldigi on the laptop knows about all possible PSK and RTTY home frequencies, including those on bands I don't use a lot.
  • Both batteries I brought got depleted really quick when transmitting with 50 watts. I need more battery capacity.

Tags: , ,
2017-02-24 Seeing the same amateur stations in contests 2 months ago
As I process the eqsl confirmations that come in after the Russian Worldwide PSK contest 2017 I start to notice some callsigns are showing up regularly in (digimode) contests. My highest number of confirmed contacts via eqsl which are related to contesting come from YO9AGN, S58X, S51AF, RA3GZ, HG3FMZ, EA3HKA, 9A4FS.

But the number one callsign I have confirmed via eqsl is not a contest station but the Veron club station PI4AA where I try to call in to the net almost every month.

Tags: , ,
2017-02-20 I participated in the Russian Worldwide PSK contest 2017 2 months ago
This weekend I had time to use the radio and after trying to get some more contacts on the 30 meter band Friday evening I decided to participate in the ongoing digimode contest in the weekend. This was the weekend of the Russian Worldwide PSK contest 2017 (https TLS certificate is broken at the moment).

I had fun doing it, had 124 contacts in the contest. I now have two new countries in the log: Kuwait and Suriname. And Kuwait already confirmed via Logbook of The World. I just uploaded the log (with the last contact rejected as it was too late):
Band  QSOs Dupes Points Mults
160      0     0      0     0
80       0     0      0     0
40      52     0    320    28
20      71     0    223    33
15       0     0      0     0
10       0     0      0     0
======================================
Total  123     0    543    61
Claimed score is 33123 points
Comparing it to my results in the Russian WW PSK contest 2015 I did a lot better. At that time I still had limited access to the 40 meter band which limited my options for PSK traffic.
Read the rest of I participated in the Russian Worldwide PSK contest 2017

Tags: , ,
2017-02-15 JT65/JT9 on 30 meters, even getting a new US contact 2 months ago
Today I threw out the longwire antenna and tuned it for the 30 meter amateur band (10.100 - 10.150 MHz). I first tried the PSK part of the band but that was completely silent. I tried the JT65/JT9 part, and that part was buzzing. And beeping, and other sounds. I made several contacts in Europe in the morning which was as expected. But in the evening the computer/radio was still running and I noticed some US callsigns, and answered one, and had a JT9 contact with K8SIA.

After that it was time to get the longwire antenna back in the house again. All in all another good experience with the 30 meter band.

Tags: , ,
2017-02-12 Rising number of amateur radio contacts 2 months ago
I noticed recently the number of radio contacts made by my new callsign PE4KH which I started using in March 2016 was getting close to the number of radio contacts made by my previous callsign PD4KH between March 2013 and March 2016. A typical rise in contacts, mostly due to my skills improving and participating in contests. So I wanted to view the rise per month and did some searching how to ask the cqrlog databases and plot the results.

Oh, and now PE4KH has more contacts after a few new contacts logged in PSK31 mode on the 20 meter band today.
Read the rest of Rising number of amateur radio contacts

Tags: , ,
  Older news items for tag hamradio ⇒
, reachable as koos+website@idefix.net. PGP encrypted e-mail preferred.

PGP key 2C66 3B5D F0D7 C263 local copy PGP key 2C66 3B5D F0D7 C263 via keyservers pgp key statistics for 0x2C663B5DF0D7C263 Koos van den Hout
RSS
Other webprojects: Camp Wireless, wireless Internet access at campsites, The Virtual Bookcase, book reviews, Weather maps