2018-04-04 Building my own balun, part 3: First work on the case 3 months ago
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:
- Building my own balun, part 1: idea and parts needed
- Building my own balun, part 2: measuring the 'old' balun
- Building my own balun, part 4: Deciding on where to put dipole ends and finishing it
- Building my own balun, part 5: First tests of the result
- Building my own balun, part 6: Redo and some success: a working antenna again
2018-04-04 Building my own balun, part 2: measuring the 'old' balun 3 months ago
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
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.
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.
2018-03-19 Building my own balun, part 1: idea and parts needed 4 months ago
I was considering hanging a dipole antenna outside. This would need a balun and I realized that I have a good outdoor-capable balun hanging in the attic. It's a Fritzel 1005 1:1 current balun which is good up to 300 watts power. I am not going to use 300 watts under the roof close to other equipment and the balun there does not need to be rain proof. So the idea was born to build a smaller balun for use under the roof and have the Fritzel balun available for outdoor use. And last Saturday was a hamfest (radio onderdelenmarkt Rosmalen) so I had an idea of things I wanted for this project. Parts needed for a current balun:Read the rest of Building my own balun, part 1: idea and parts needed
The various collections of electronics parts only missed the SO239 socket and a case. Those were found at the hamfest for a nice price. The choice of design is a current balun or a voltage balun. I had to do some searching to find a good comparison between the two, and DX engineering has one at Baluns: Choosing the Correct Balun - DX Engineering which has:
- A ferrite core with the right specifications
- Wire with enamel coating
- An SO239 socket
- Terminals for connecting the dipole wires
- A caseCurrent baluns, rather than voltage baluns, should be used whenever possible. Current baluns provide better balance and often have lower loss. Current baluns, especially 1:1 ratio baluns, tolerate load impedance and balance variations much better than voltage baluns.Some searches found good explanations of building your own baluns, I found a very clear explanation at VK6YSF project page. So I'm building a current balun, and when it's finished enough to test it I will measure how it is doing. I have the tools like the SARK100 antenna analyzer that I can control from Linux and a dummy load so I can check everything.
2018-03-12 I participated in the EA PSK63 Contest 2018 4 months ago
As planned I participated in the EA PSK63 contest 2018 last weekend. As this contest starts at 16:00 UTC and not the usual 12:00 UTC I decided to again try my luck as single operator on the 40 meter band only (SO 40 DX for this contest). Contacts were made Saturday evening and Sunday morning and afternoon. Sunday at 12:45 UTC I gave up on finding any new callsigns on the 40 meter band and decided to switch to the 20 meter band. Conditions were not very good and I think I made some errors copying serial numbers or on the decision whether to count a contact as valid. And at least two calls had me in their log but my log was not convinced we made a contact around that time. In the end I made 125 contacts, 79 on the 40 meter band and 46 on the 20 meter band. Looking at the results of previous years I thought I would end up with a higher ranking with the 79 contacts on the 40 meter band only so I entered in that category. The 20 meter contacts will only count as checking for the other participants. The one that got away: I saw an amateur from Thailand call CQ but my answer did not make it back there. A nice contest. I was able to practice fast contacts a bit even in difficult conditions. As usual with all contests I also uploaded my score to the Veron Afdelingscompetitie where our local chapter A08 is doing ok.Read the rest of I participated in the EA PSK63 Contest 2018
2018-03-04 Trying a bit of radio at a holiday park 4 months ago
Last week we were staying in a holiday home in the Ardennen area in Belgium. Temperatures were constantly below zero which can make my fibermast break easily according to the instructions. I also forgot to bring a side cutter so setting up the fibermast with the rubber profile at every level would be hard to take down again. This made it a bad idea to leave it up overnight. Due to the cold and me having a serious cold as well it took a few days before I got around to a bit of amateur radio. When I got around to setting up the mast it went reasonably well. The ground was frozen so I needed a hammer to get the pegs into the ground for the guy wires. The foot of the fibermast decided to slip away and the tip fell against a wall, but no damage. When the mast was up and the dipole hanging the local RF noise turned to be at the same S8 level I am used to at home and it was very hard to make a contact. I tried 40 meter FT8 with transmit power dialed back to 25 watt since the radio itself started showing signs of RF interference. One partial contact was made (no full exchange of signal reports). And then I noticed gardeners working on pruning bushes everywhere and working in my direction so I disassembled the mast again and took all the parts back in. For next time I may find some plate to anchor the foot of the fibermast so it can't slip away. Maybe a plate with a big hole in it for the mast and two small holes for tent pegs.
2018-03-02 I am planning to participate in the EA PSK63 contest 2018 4 months ago
This year I am planning to participate again in the EA PSK63 contest edition 2018. Although the weekend is not completely free there will be time to get as many spanish stations and others in the log as possible. Time to find out if I can improve my score from participating in the EA PSK63 contest in 2016.
2018-02-19 Again new countries in amateur radio in a pair 5 months ago
This evening another two new countries in my amateur radio log: Lebanon and Gibraltar. First OD5ZF from Lebanon and 4 minutes later ZB3M from Gibraltar. That makes three pairs in two months. These two were both in FT8 mode on the 40 meter band. FT8 is very good at fast contacts at low received signal levels.
2018-02-18 Two new countries in the log and I participated in the Russian worldwide PSK contest 2018 5 months ago
Two new countries in the PE4KH log: Oman and India. Oman was Friday afternoon when I was home early and decided to turn the dial over the 40 meter band to make some phone contacts and heard A41CK call. Who took my call on the second try! India was late Friday evening. The call VU2NKS showed up in FT8 and it had a direct pile-up (lots of people answering). But with some persistance from my side and good operating skills from the other side the contact was made. And this weekend was the Russian Worldwide PSK Contest so I participated Saturday afternoon / evening and a bit Sunday right before 12:00 UTC. I managed to start Saturday 12:00 UTC sharp calling CQ. Which worked at that time for getting contacts. I chose the 40 meter band category because I expected most radio time this weekend would be after sunset. In the end I made 64 contacts. Not a very high score, but I had times were several contacts happened in short succession so I am improving in digimode contesting.Read the rest of Two new countries in the log and I participated in the Russian worldwide PSK contest 2018Band QSOs Dupes Points Mults 160 0 0 0 0 80 0 0 0 0 40 64 0 388 28 20 0 0 0 0 15 0 0 0 0 10 0 0 0 0 ====================================== Total 64 0 388 28 Claimed score is 10864 points
2018-02-11 Plotting the number of amateur radio contacts 5 months ago
After the end of January I decided to plot the number of contacts again. January is a busy month with two contests for me but I did not make a lot of contacts outside of those contests this year. I added contacts from holidays and the PE4KH/P activities to the total count. Some more work on the plot script, I think bars look better than a line graph. But you could spend hours in gnuplot making the plot just right... The new script:set output "qslcount.png" set terminal png size 640,300 fontscale 0.7 set timefmt "%Y-%m" set xlabel "Month" set ylabel "Number of contacts" set xdata time set style fill solid set xtics format "%b %Y" set xtics rotate set grid set boxwidth 0.75 relative set autoscale xfixmin set autoscale xfixmax plot "dataset-qsocount" using 1:2 title "Contacts/Month" with boxesUpdate: And indeed the change in x autoscale was one bit more 'just right'. The first graph was in February 2017: Rising number of amateur radio contacts.
2018-01-15 I participated in the UBA PSK63 prefix contest 6 months ago
As planned I participated in the UBA PSK63 prefix contest in the weekend. Activity was Saturday evening and Sunday morning interrupted by some good sleep. Compared to my experiences in the ARRL RTTY roundup one weekend earlier the 40 meter band decided to act quite differently. On Saturday evening it was quite hard to make a contact. A lot of interference, no far away stations and it was hard to get heard by the other side. I stopped before 22:00 UTC (23:00 localtime) because I thought some sleep would be more effective than getting annoyed by the lack of contacts. Indeed, Sunday morning things got better although I heard only nearby signals on the 40 meter band, including some Belgian stations. No serious DX. Belgian stations are good for extra multipliers so it was good for the score. In the end I made 76 contacts. The last contact was started by a CQ I called at 11:59 UTC but it was only answered at 12:00, so it does count but I had to note it in the log as originating at 11:59 where the software normally logs the moment I see the callsign for the first time. Log submitted and de Veron afdelingscompetitie updated.Read the rest of I participated in the UBA PSK63 prefix contest
2018-01-12 I am planning to participate in the UBA PSK63 contest 6 months ago
As in previous years, I am planning to participate in the UBA PSK63 Prefix Contest in the upcoming weekend. I can't participate for 24 hours since other things have to be done too in the weekend including the all important 'sleep'. I just finished the preparations:Read the rest of I am planning to participate in the UBA PSK63 contest
On Saturday evening the 20 meter band will probably be closed by the time I am available for contesting. So I'll start on the 40 meter band. The choice for 40 meter band only or all band will have to be made on Sunday morning, depending on the amount of new contacts I can make in the 40 meter band.
- The endfed antenna for 10/20/40 is hanging outside
- The contest macros have been updated to call CQ UBA PFX TEST
2018-01-08 I participated in the ARRL RTTY Roundup 2018 6 months ago
For the past weekend I had the ARRL RTTY Roundup planned, meaning I had reserved time in the family calendar. Other things had to happen too but I reserved time for contesting and made sure I had the right macros available before the contest started. I hoped to find time to set up the endfed antenna before the contest but that did not happen so it was the first thing to do when we got home at the beginning of Saturday evening. In the contest I only operated on the 40 meter band. Most of the time I was able to participate were in the dark when I did not expect the 20 meter band to cooperate and I thought that operating in just one band would make me end higher in the rankings for that more specific category. Only after the contest I read the rules exactly and noticed that this specific contest does not differentiate between single and multi band operation. In the end I made 95 contacts. Local noise is high in my current setup so only the strongest stations came through the noise. I made only one contact in CQ mode, the rest was search and pounce. Propagation wasn't really good until late in the evenings when I managed to score some US contacts. I did see someone from Prince Edwards Island in Canada but that station did not hear me return. I noticed WP2B did not give me a US state but a serial number and found out that is a US Virgin Island callsign, so that was a new country for me. In the end a nice contest. For upcoming contests: check the rules / propagation predictions and plan my strategy.Read the rest of I participated in the ARRL RTTY Roundup 2018
2017-12-27 The 10 meter band is alive the last few days 6 months ago
Yesterday on the 26th of December I saw FT8 activity on the 10 meter amateur radio band (28.0 MHz-29.7 MHz) and made a few contacts. Propagation dropped around 12:35 UTC after which I made one contact with a nearby amateur. Today I spun the big dial on the radio to the 10 meter band after dark and made contacts (around 17:20 UTC). This is extra special as the maximum frequency at which propagation across the ionosphere occurs drops after the sun stops illuminating it and therefore the 10 meter band is the first band to drop after sunset. All this was predicted: the most recent 'space weather news' had some good news for radio amateurs. Today I found an article The sun will probably knock out the grid someday | Popular Science which mentions the 'Space Weather Woman' Tamitha Skov and her youtube channel TamithaSkov. I have watched a few episodes and I read articles here and there with the predictions of solar flares and solar wind.Read the rest of The 10 meter band is alive the last few days
2017-12-24 First radio contact with Armenia 6 months ago
As if one new country today wasn't enough, I also managed to get Armenia in the log with station EK1KE also in FT8 mode.
2017-12-24 First radio contact with Australia 6 months ago
A special first for me: an amateur radio contact with Australia, with VK3EW who seems to be a serious DX chaser. For me, this is almost the other side of the world. This was an FT8 contact, which is a digital mode specific for making contacts with very weak signals using the minimal exchange of information to have a valid contact. I think the neighbours have heard my happy shout after I saw the first response come back to me. The exciting part was making it a full contact complete with signal reports exchanged. The distance of this contact is 16581 kilometers! The scaling of the generated maps at PE4KH amateur radio has been adjusted to make this contact visible.Read the rest of First radio contact with Australia
2017-12-02 Preparing gpredict for AO-91 Fox-1B RadFxSat 7 months ago
Although reports are showing up that AO-91 has the usual 'zoo' when it's over southern Europe I still want to prepare for making contacts on interesting passes. So I dove into adding satellite transponder details to Gpredict again. According to [amsat-bb] AMSAT-OSCAR 91 identified it is Norad object 43017. And when Nico Janssen finds a satellite using his methods of doppler-curve fitting it's a very good indication it's the right one. So time to create a .config/Gpredict/trsp/43017.trsp with the right frequencies and details:[Fox-1B trsp 67 Hz PL] UP_LOW=435250000 DOWN_LOW=145960000 MODE=FMNow to find a pass at a for me usable time.
2017-11-25 Portable operation close to my home 7 months ago
Today I had some time left and the choice was between staying at home and throwing out the endfed and making a lot of contacts in digital modes or going out and trying a nearby park and making a lot less contacts but learning about my options there. I chose the latter one: I loaded my gear in the bicycle trailer and cycled to a nearby park, just outside the city limits of Utrecht. I took the fiber mast and used two elastic straps to tie it to a parkbench. The effect was that the mast was slanted but using it with the wire of the endfed twisted around it the fiber mast stayed up fine without needing its guy wires. And I forgot to bring the tent pegs anyway so I was unable to guy the mast. I tried the endfed as a vertical with some slack at the bottom and the transformer at the bottom. This gave me a horrible standing wave ratio on 40 and 20 meters. I guess the endfed is only balanced when it is stretched. The quick fix was to add a common-mode choke in the coax to the radio. I also added a counterpoise wire to the earth of the endfed to be somewhat balanced again. On the 40 meter band reception was ok but I could not understand a lot of stations. On the 20 meter band there was local interference. In the end I logged one whole contact on the 40 meter band with an Italian special event station. He gave me a 4-4 report and I gave him a 5-9+. After a few tries I gave up making him log me as /portable so I logged it in my PE4KH log. The location is still within JO22NC so I logged in my home log. As soon as the sun set it started cooling down and the grass got wet and I went home. It's a nice location and quite reachable from home. It's 10 minutes cycling and in 10 minutes I had the mast and the radio set up.
2017-11-08 Trying to receive Fox-1A (AO85) telemetry 8 months ago⇐ Newer news items for tag hamradio Older news items for tag hamradio ⇒
I decided to try to receive telemetry data from the Fox-1A (AO85) satellite to prepare for receiving telemetry from the new RadFxSat right after launch. The FoxTelem program is ready to receive data from all the Fox series satellites so this was a good way to test my receiving setup. This afternoon there was a reasonable pass so I decided to give it a try. With the FT-857D radio tuned to the downlink frequency 145.978 MHz in FM packet mode. While I did hear the conversations on the satellite in the noise the program did not seem to receive anything. And then I noticed the sound display in the program reacted strongly when I tapped the microphone connected to the mixing board. I chose the wrong audio device. I have two USB audio devices connected to the computer, one feeds audio from a mixing desk and one feeds audio from the radio. Normally I can keep them apart but FoxTelem was only showing one of them. The solution was to set FoxTelem to the audio device 'default' and use pavucontrol to switch the input of the application to the right USB audio device. But by the time I figured that out the satellite was already too far to receive any useful telemetry data. Time to find another nice pass with useful elevation (above 10 degrees) to try this again. And it's a good preparation for the launch of Fox-1B.