I passed my radio amateur exam in March 2013 and I registered the callsign PD4KH (pappa delta four kilo hotel!). I plan to do my first experiments 'bicycle mobile' from my recumbent.
I am located around maidenhead locator: JO22NC
For now this page contains just the 'hamradio' items from my homepage.
D-Star digitale amateur radio (Nederlands)
Vandaag is het precies 34 jaar geleden dat 27 MHz communicatie in Nederland werd geintroduceerd, 27 MC artikel op de nederlandse wikipedia. Ik luister wel eens met een scanner naar 27 MHz verkeer, erg vermakelijk.
I almost started to digres in my last post getting an APRS report out using an android device, aprsdroid and a wouxun radio about the privacy implications but decided to separate that issue. It works, and I am not going to invest in it. APRS is nice, but for me it has privacy implications: it reports my position in real-time which is more than I want to share with the world, even as an amateur radio experiment. I know there are people who will post their bicycling tours or runs on-line as they happen but I don't like publishing my wereabouts, especially not in (near) real-time. Enough people can browse the mobile telecom location registers as it is. So I think I'll leave the APRS location experiments at this and I'll go look at other amateur radio stuff. There is enough to play with! I know APRS is bigger than just reporting location. Getting my weatherstation in Utrecht Overvecht to report weather to the APRS citizen weather observer program is on my wishlist.
Again playing a bit with APRS and aprsdroid. No luck with using a 3.5mm to 3.5mm audio cable, the vox on the wouxun KG-UVD1P does not trigger at all. I did test with the audio from aprsdroid near the microphone of my laptop and decoding it with multimon, and that works:AFSK1200: fm PD4KH-7 to APDR12-0 via WIDE1-1 UI^ pid=F0 =5206. N/00507. E$/A=000162 http://pd4kh.idefix.net/The 'audio through the air' method works with the radio right next to the internal speaker of the android device: with some fiddling of audio settings on the android device and vox settings on the wouxun I can send out a position report and it shows up on the aprs network! Wouxon vox level at 5, audio output type "music", audio level medium. The pink square is because I don't give out a very precise location on purpose.
I decided to try aprsdroid on my android device. First and easiest should be to select the option AFSK via Speaker/Mic and I hoped it would work when the speaker and microphone of the portable radio are near the microphone and speaker of the android device. No luck: no transmitted APRS packet was found via aprs.fi call PD4KH and no incoming packet was decoded. I guess there was too much distortion and interference. I looked at the aprsdroid settings a lot since I noticed outgoing audio seems to be fixed at the highest volume, which can also be an issue. In the video Get Started with APRS for only $30! - youtube.com video a simple cable from the android device to the radio is used, so it can be done. Going for a solution like an Mobilinkd is more expensive, but maybe interesting in the long run when I want to do more with APRS. For now, an interim solution would be nice: building the right cable to get audio from the radio to the android device and back. I found the specs for such a cable at iPhone / Baofeng interface bouw en schema - PA4TW which can be adjusted for the android device and Wouxun. And PA4TW has used it for APRS in Aprs via porto en iPhone - PA4TW. Old analog telephone equipment can be a source of 600 ohm 1:1 transformers, so I guess some old equipment will have to donate those when I go for such a cable.
The change to the new weatherstation computer also means the powerline network is now gone. And I mean gone, not just disconnected "just in case". The adapters are back in a crate. And this should mean the HF spectrum should look nicer than in my earlier measurements. Future measurements may confirm this. The weatherstation computer now uses Wi-Fi to talk to the rest of the network. Since the access-point is on the same ground level the signal quality is good and speed is high enough.
Een mooi verhaal over een enthousiaste jonge beginnende radio amateur die met wat hulp mooie dingen aan het doen is: PI4RCG sponsort Lithouwse novice zendamateur LY5AT, door PA3FYM.
I had a look what software is available for predicting satellite passes in the ubuntu ham radio software repositories. PREDICT satellite tracking and orbital prediction program which does all the calculations given recent Keplerian elements which are available from sources like Keplerian elements at Amsat and Current NORAD Two-Line Element Sets at celestrak. Predict comes in two versions: predict in a version from May 2006 and predict-g1yyh. They look a bit different but the calculations are the same in the end. Important part (to me) is the software also does the calculations for doppler shift. Doppler shift does occur measurably in radio signals when the two stations have a high enough speed difference between them. Since amateur radio satellites are low earth orbit satellites, the speed is measured in kilometers per second and the shift is there and should be taken into account. Shifts in the 70cm band are high enough that you need to retune the radio. As visible in the screenshot predict does calculate the frequencies when the satellite is visible. gpredict which is totally not related to predict. In my opinion gpredict has a more modern interface (it's gtk+ based)
but it lacks support for doppler shift. This makes it somewhat less interesting for radio use.
I wanted to experiment a bit with rtl_tcp on ritchie which has linux kernel 3.12, and after inserting the stick I noticed the following in the syslog:[405465.908104] usb 1-3: new high-speed USB device number 2 using ehci-pci [405466.052247] usb 1-3: New USB device found, idVendor=0bda, idProduct=2838 [405466.052274] usb 1-3: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [405466.052293] usb 1-3: Product: RTL2838UHIDIR [405466.052310] usb 1-3: Manufacturer: Realtek [405466.052328] usb 1-3: SerialNumber: 00000001 [405466.217234] usb 1-3: dvb_usb_v2: found a 'Realtek RTL2832U reference design' in warm state [405466.285098] usb 1-3: dvb_usb_v2: will pass the complete MPEG2 transport stream to the software demuxer [405466.285208] DVB: registering new adapter (Realtek RTL2832U reference design) [405466.348588] usb 1-3: DVB: registering adapter 0 frontend 0 (Realtek RTL2832 (DVB-T))... [405466.378308] r820t 0-001a: creating new instance [405466.390283] r820t 0-001a: Rafael Micro r820t successfully identified [405466.397306] Registered IR keymap rc-empty [405466.397785] input: Realtek RTL2832U reference design as /devices/pci0000:00/0000:00:0f.5/usb1/1-3/rc/rc0/input5 [405466.404262] rc0: Realtek RTL2832U reference design as /devices/pci0000:00/0000:00:0f.5/usb1/1-3/rc/rc0 [405466.449642] IR NEC protocol handler initialized [405466.453552] IR RC5(x) protocol handler initialized [405466.459768] IR RC6 protocol handler initialized [405466.470835] usb 1-3: dvb_usb_v2: schedule remote query interval to 400 msecs [405466.471385] IR JVC protocol handler initialized [405466.474504] IR Sony protocol handler initialized [405466.481423] IR SANYO protocol handler initialized [405466.483311] usb 1-3: dvb_usb_v2: 'Realtek RTL2832U reference design' successfully initialized and connected [405466.483477] usbcore: registered new interface driver dvb_usb_rtl28xxu [405466.493045] input: MCE IR Keyboard/Mouse (dvb_usb_rtl28xxu) as /devices/virtual/input/input6 [405466.498074] IR MCE Keyboard/mouse protocol handler initialized [405466.501562] lirc_dev: IR Remote Control driver registered, major 251 [405466.510997] rc rc0: lirc_dev: driver ir-lirc-codec (dvb_usb_rtl28xxu) registered at minor = 0 [405466.511017] IR LIRC bridge handler initializedIt has valid drivers as dvb-t receiver and ir receiver now! That's not what I wanted, I want raw usb access for rtl_tcp. Time to blacklist certain modules:blacklist dvb_usb_rtl28xxu blacklist rtl2830 blacklist rtl2832 blacklist lirc_devAnd now no drivers get loaded and rtl_tcp has raw usb access again after updating the udev rules. No success with gqrx using a remote rtl_tcp: audio was stuttering and frequency changes were visible in rtl_tcp but didn't really happen, there was a huge lag. Traffic between the system running rtl_tcp and gqrx was going over a wireless network, a linux router and a wired network. Bandwidth was not a problem. I was considering running one rtl-sdr stick with the HF convertor in the shed so it would have less interference but that doesn't seem feasible at the moment.
Vandaag moest ik wat dingen met de auto doen. Daarmee kon ook de porto mee met de raamantenne aan de buitenkan van de auto. Dat werkte prima, PI3UTR was prima te volgen en een QSO maken lukte ook zonder problemen. Met dezelfde porto en hetzelfde vermogen waarmee ik op de ligfiets er maar moeilijk overheen kom lukte het met een net iets hogere antenne die zeker rechtop zit prima.
Ik was vandaag op de heuvel Hettenheuvel in het Bergherbosch bij Braamt. Ik had de porto mee en op een kant van de heuvel met zicht naar het westen probeerde ik PI3UTR te ontvangen wat lukte. Niet storingsvrij maar duidelijk genoeg om de callgever te verstaan (Q3). De repeater openen lukte niet met de 5W porto. Volgens het hoogtebestand Nederland is de hoogte daar 70 tot 90 meter. Ik heb daarna eens aan deze link gerekend in Radio Mobile online en gezien dat van PI3UTR naar deze locatie line-of-sight precies door de bomen van de heuvelrug gaat. De afstand was dus iets meer dan 81 kilometer. Dit geeft wel aan waarom deze repeaterfrequentie gecoördineerd moet worden met Duitsland: het Bergherbosch is nog net niet in Duitsland, maar het scheelt weinig. Op een hoge locatie aan de andere kant van de grens of bij condities zal deze zeker te ontvangen zijn.
Today I listened to an amateur radio on the International Space Station (ARISS) contact: Saturday 28 December, ARISS contact planned with Scout group in The Netherlands. This time I listened in the backyard at home, which is a lot more enclosed by other buildings than the location I used on the previous pass, the roof of a 4-floor building at work. Reasonable reception started in the answer to the 7th question and dropped away in the answer to the 14th question. Good to hear scouting and ham-radio being used in such a way!
When I get around to wardriving lately I use the wigle app for android, so I decided to repurpose the wardrive box as shednet computer. This will also mean I can stop using PLC network to link the shed computer to the rest of the network, replacing it with wifi. Using PLC offends the radio amateur in me and people at the radio club now ask me whether I dumped it already. So, time for different hardware which as a plus will also use less power. I already built in a laptop harddisk in the wardrive box and removed the compact flash holding the wardriving box image (I'll save it so I can restart using the wardriving box if needed). The alix 1c can work nicely with an IDE laptop harddisk.The installation will probably be done with a recent debian jessie distribution. Plans for the new shednet computer include an ntp server, but since the current gps unit (gpskit) seems to fail after running for a few days in the test setup that may have to wait.
The laptop harddisk built into the ritchie mini-itx case
Conrad maakt in z'n laatste mailing reclame voor een Conrad POF thuisnetwerkkabel starterkit. Alleen ik kan nergens terugvinden hoe snel data over plastic optic fiber (POF) kan. Ik dacht uit het verleden dat dit beperkt was tot 100 megabit maar misschien is er een nieuwe standaard die wel tot gigabit gaat. Plastic optic fiber kan een goeie aanpak zijn om in huis langere afstanden te overbruggen zonder terug te vallen op ethernet over stroomnet. In de voordelen van plastic optic fiber noemt Conrad ook Geen afstraling (elektrosmog). Ik zou 'geen radiostoring' een betere omschrijving vinden, maar dit spreekt natuurlijk meer aan.
To my shame as a radio amateur I must admit I still use a PLC (ethernet over powerline) connection in my home network. It's what makes the shed weather station computer reachable. An upgrade to wifi is in the plans.
Trying the mini-whip antenna in a different corner of the house on the AM MW broadcast band. Some interesting new stations:621 kHz RTBF International 154km 693 kHz BBC Radio 5 Live 494km 711 kHz France Info 667km 738 kHz RNE Radio Nacional 1191km 810 kHz BBC Radio Scotland 726km 855 kHz RNE Radio Nacional 1147km 864 kHz France Blue 430km 918 kHz Radio Slovenija 1 954km 945 kHz France Info 1001km 954 kHz ČRo Plus 574-894km 1107 kHz TalkSport 381km 1134 kHz HRT-HR 1 1149km 1215 kHz Absolute radio 494km / Voice of Russia 1137km 1269 kHz Deutschlandfunk 383km 1341 kHz BBC Radio Ulster 790kmThis time Radio Vahon clearly on 1557 kHz. 1215 kHz was harder to determine but I clearly heard both stations!
In disassembling a very old original Apple external CD player I came across a big ferrite core. I thought this would help solve the problem with 2 meter band interference from the Das Keyboard. And indeed, there is a lot less interference on the 2 meter amateur band. I tested with the Wouxun KG-UVD1P radio tuned to 145.500 MHz and I had to put the antenna of the radio real close to the keyboard to hear interference with the squelch set at 5. Update: I notified the makers of Das Keyboard of this problem and my solution. The reply was a bit non-committal they will forward the suggestion to development.
Interesting dipole design: Ham Radio 2m/70cm Vertical Dipole Antenna - Dave Tadlock on YouTube found via Zelfbouw 2m/70cm dipooltje - zendamateur.com and De 10 euro dual bander (2/70 cm) professional look - zendamateur.com. This could be an interesting future 'under the roof' antenna.
Trying the AM broadcast band with the mini-whip antenna, HF upconvertor and the rtl-sdr stick with gqrx software. Reasonable reception of:675 kHz Radio Maria 11km 747 kHz NPO Radio 5 38km 792 kHz France Info 742km 837 kHz France Info 364km 882 kHz BBC Radio Wales 594km 909 kHz BBC Radio 5 live 366km 1008 kHz Groot Nieuws Radio 38km 1053 kHz Talksport 494km 1089 kHz Talksport 366km 1377 kHz France Info 229km 1422 kHz Deutschlandfunk 329km 1440 kHz China radio international 236km 1458 kHz BBC Asian network 472km 1584 kHz Radio Paradijs 1kmStations were fading and I 'cheated' by looking at the AM reception prediction at fmscan.org to confirm languages and service names where I also got the distances from. I am trying to find out what I hear on 1557 kHz which can be either Vahon Hindustani Radio from 49km away or France Info from 937km away. There was a very interesting article about the transmitter setup for Vahon in the Electron magazine of the Veron radio amateur club. Constant fading makes it hard to understand but at one moment I heard music which I also heard on the livestream from Vahon and at another moment I heard speech in French.