The sun keeps on giving.
Today's SFI (21cm solar flux) is 212. I think this is the first time in this cycle the SFI has been above 200.
With a few more days of this high flux I would not be surprised to see 6m opening with F2 propagation.
Exciting times!
Before the NanoVNAs became widely available it was tricky to find low cost test equipment for testing SWR or return loss in the low GHz range.
At the time I did find one possibility: The transverter-store in Ukraine sold some low cost impedance bridge PCBs, so I got myself one.
The PCB bridge circuitry looks like this:
Looking at a Youtube video I found that the PCB has a fault. The bridge has 2 50Ohm resistances, made up by two 50Ohm resistors that should be connected in parallel. On the PCB he tested, and on mine, this is not the case. No connection between 2x two islands on one side of each pair.
Now, this is not difficult to correct. A short piece of wire mounted at the junctions between the resistor pairs solve this.
A quick test using my NanoVNA 2 showed a shortcoming of the NanoVNA output level (too low), but also gave an indication of the functioning of the bridge.
With a 6dB attenuator as the DUT (Device Under Test) the return loss showed close to 12dB, as it should.
Testing a 10dB attenuator the same way showed that the return loss went down into the noise of the NanoVNA. Close enough to 20dB, so I accept the reading as correct, and that the bridge is working properly.
That is the end of mini project #1 of this year.
Will I use this bridge a lot? Not really, but I did want it to be in working order. It is now going into the test PCB pile as a working unit.
The NanoVNAs that came out after this are much easier yo use, and much more versatile. The cost is not prohibitive, so in the lab I will be using a NanoVNA F (I think is the designation) for frequencies up to 1GHz, and a NanoVNA v2 for up to 4GHz.
Some "new" (actually old, but recurring) sunspot groups just rotated into view of Earth.
3 days ago one of them fired a flare of magnitude X1, and minutes ago the sun fired again. This time X2 - well strictly speaking X1.98, but I made the rounding-up. This is bound to create a sudden Ionospheric Disturbance (short wave fade-out) on the day side of Earth, and it will likely las a little less than an hour.
Also the 21cm solar flux is at 184 today. If this continues for several days more I suspect that there is a good possibility of F2 openings on 6m.
I will be aware and monitor the situation.
I have an idea for an addition to the challenge/wish list for 2023.
In my shack, and in the lab there are a ton of small projects that will improve the ability to make larger projects.
This could be an extremely simple repair or modification of some existing equipment or a PCB module.
The intention is to make a small blog entry for each of mini projects.
There should be one mini project per month as an average, so 12 of them this year.
Why?
Sometimes I get the impression that I do not doo anything, even when I do. So this is to show me that I do, in actual fact do some stuff, even if not as much as I want to do.
This is, of course in addition to doing a few larger projects.
Last year's large project was making a minimum of 365 QSOs with 5W output, so I suspect this year I will make fewer QSOs, as I have some practical building projects I want to get done.
Let us see how that goes.
We have entered a new year, 2023. Let us take a look at what may or may not accomplish this year.
I have been writing on this blog for a while now.
Some may wonder why I do it. So I write this reminder.
Here we go:
I write here as a reminder of things I have done with ham radio, and also a a notebook of ideas.
If any of my writing is useful to you or anyone else, that is perfect. That is some of my contribution to ham radio.
I will continue to write about what I find fun or interesting about it. Good experiences. Great ones. Some experiments. Some challenges, Some projects. Ideas.
All a mixture of what you will find here.
I may even expand the content of the blog. We shall see. To me the main point is that it has to be fun, or at the least interesting.
Be seeing you a bit later this year, and more.
73 and Happy New Year, de Jan, OZ9QV
A "few" words on what should be next year's challenge.
0) The open home brew challenge goes on. This is all about making at least one QSO on as many bands as possible, with home made equipment. This could be a kit I built, a fully home constructed transmitter and/or receiver, or modified versions of equipment not designed for amateur radio.
I do intend to get some more kits built next year, and use some of those already built for HF band monitoring. A part of the propagation study may include a WSPR and/or WRSS transmitter, and/or some WSPR/QRSS monitoring, and more bands with FT8 monitoring when I am not actively operating on the bands.
Apart from the kits, I may get to some more home construction. We shall see.
1) The primary challenge for 2023 will be all about improving the solar power system and its efficiency for the amateur radio station.
In particular, all systems for monitoring the radio propagation has the highest priority. This includes both the improvement of the capacity of the solar panel and battery system and reducing the power consumption of the receiving systems.
More solar panels are needed for charging the battery. I expect to increase the peak "capacity" of the panels to somewhere between 600 and 900W. The precise configuration is yet to be decided. Currently I have a peak capacity of 250W and a non-optimal position for the panels.
An improved system of solar charge controllers. MPPT controllers are inherently more efficient, though they tend to be more noisy in the radio spectrum. I found some that seem to be relatively quiet, but the3y are not yet tested at full charge current. I suspect that they can be useful with good RF filtering at the inputs and outputs.
Improved battery capacity. The 12V system for the station should be updated to 400Ah capacity at 100% charge.
The aim is to provide pure solar power to the minimum requirements of the station all through winter.
This leads to the next part: Minimizing the power requirements of the station, especially the parts that will be required to run 24/7, or many hours per day, such as some propagation monitoring and monitoring e.g. local traffic on 2m.
2) The other challenge is concerned with microwave activity (above 1GHz) The aim is to make at least a first QSO on a few microwave bands. starting with 2.4GHz and 10GHz. Long ago I was active on 23cm, but I would very much like to get going on that band, too. If I can get away with making experiments on 3.4, 5.7 and 24GHz, that would be nice, too. Improving the QO100 system is part of this, too.
I am already active on the QO100 satellite. This means that I have transmit capability on 2.4GHz and some receive capability on 10GHz.
This system is rather primitive, and many improvements can be made to it, especially on the receive side.
a) Further, I located a 23cm (1.3GHz) module for the IC-910, as well as a more precise and stable reference oscillator (TCXO) for that transceiver. During the winter nights I need to make sufficient space on the lab desk, so I can get going with mounting those, and also make a fresh alignment of the transceiver. Straight forward when the space is available.
As the IC-910 is quite heavy I intend it for home operation only. If I want to go portable on 1.3GHz I will need a transverter and a portable transceiver. I could use one of the FT817s or the IC-705. Both need modifications, so the transverter(s) are not blown up if they get high power TX signals in.
I will still need to get some antenna up for 1.3GHz. This should happen some time in the spring. I expect to use a Diamond X-5000 (I think) for vertical omnidirectional (mostly FM) with a 23cm preamp, and a small yagi, like the front mounted Flexa antenna for horizontal polarization (mostly SSB/CW/digital modes). The horizontal antenna will need a rotating system that needs to be set up. Lots of work.
For portable work I still have a small 23cm yagi that can be used on hills etc.
b) While it is possible to use my up-converter for the QO100 system for transmitting on 2.4GHZ in general, the existing system will be very cumbersome, especially when going portable.
I could possibly use the up converter with the FT817 as the transmit system, and the AR8600 SSB capable "scanner" as receiver. Operating portable from a parked car could be done with this system, but setup will take time, and I am not sure I have the patience ;)
I think that a much better system can be made with the FT817 driving a transverter from e.g. SG-Labs, and a PA. A bit of relay and sequencing will have to be made. The transverter system should be sufficiently compact for portable use, and should be easily connected to the home system.
Antennas for 2.4GHz? I have some low cost WiFi antennas, such as 16el. yagis, and some patch antennas. Both most likely have a gain of 10-12dBd gain, and can be used for the first light weight portable experiments.
For home use I would likely use a panel antenna with about 20dB gain. Again, as with the 1.3GHz system, a rotator is needed.
c) 10GHz:
It is possible to make some simple, mostly line-of-sight experiments with a modulated HB-100 module, a satellite LNB and a scanner receiver in the 500-700MHz range. Using WBFM this could likely provide 10-20km range without using anything but the modules, no dish antennas or horn antennas. More, if "external" horn extensions or just a dish for the RX part would be used. This is mostly for portable experiments.
A small system for 10GHz narrow band, with a transverter, is also on my list. Most likely a Kuhne/DB6NT transverter, driven by the FT817 or the IC705.
Other narrow band experiments could be a NBFM/CW transmitter used with a satellite LNB down converter.
First experiments will likely be portable, but long term I should have a small station running from home.
Am I likely to get all of this done? Not really, but the minimum will be to get going from home and portable on at least one microwave band.
On the solar power and monitoring front, at least I will get some improved solar energy and *some* "reduced power" monitoring done.
For quite a while the setup for my QO-100 activity has been rudimentary:
For uplink I have used an old IC-821 as transmitter, with a lot of attenuation, followed by a low cost Chinese up-converter (BU-500) indoors, about 15m RG6 coax, with a so-called 8W WiFi booster that can deliver 2 - 2.5W without modifications, feeding a 4x patch "WiFi antenna and a 1.1m dish reflector.
This provides a decent signal on the downlink side, and certainly never overloads the transponder (triggering LEILA).
For the downlink I am using a 60cm dish, a low cost synthesizer controlled LNB, modified to be controlled by an external 25MHz reference signal.
The 25MHz reference oscillator is indoors in the shack in order to minimize the temperature drift. As this is an uncompensated DIL oscillator there is, of course some drift, up to a few kHz to each side. Actually not too bad for such a simple setup.
The LNB converts the the 10489MHz signal down to 739MHz, so for now I have used an older AOR multimode scanner receiver, the AR8600. This works, and I have made some QSOs, and often participated in the Danish-speaking net on Sundays. It is a bit inconvenient with the drift, as I have to compensate by manually checking the AR8600 frequency for the beacon, and then remember to calculate the offset.
Further, the IF filters in the AR8600 are low cost ceramic filters, so for SSB and CW the selectivity is not what I am used to from my HF/VHF transceivers.
Here comes the idea: The AR8600 has an IF output on 10.7MHz, with a bandwidth of 4MHz. Why not use that to feed one of my HF radios? That way I can use the better filters of the HF radio. On top of that, a quick manual compensation of the LNB frequency drift can be made by switching to one of the beacon frequencies and retune the AR8600 so the beacon is in the pass band of the IF receiver. Then the recalculation of the offset becomes unnecessary.
This is the simplest way to improve the downlink receive system with the equipment I have at hand.
It does require using two radios, as the AR8600 is simply used as a second down converter.
If I want to eliminate the AR8600 from this there is another idea. This requires more construction, so I think I will use the AR8600 in the first instance.
I have some older TV tuner modules with synthesized local oscillators. With a bit of programming of the synthesizer chip using a microcontroller, the Arduino or the like, this can function as a down converter to an IF of 28-40MHz. One little disadvantage is that the TV tuner as-is inverts the IF band.
This can be eliminated in two ways:
1) a second down converter inverting the band once more. This adds complexity to the system, but can be done without too much building.
2) retuning the RF filters of the tuner, so the LO moves below the signal input frequency. This is the simple way, but requires more test equipment. I do have enough test equipment to do this, so if I go the TV tuner way, this is the likely way to do it.
For now, the AR8600 with HF receiver will be the way, after all the Christmas activities. I am looking forward to improving my QO100 setup.
I am still looking into what next year's "challenge" will be. It should require some activities from my side, on the other hand it should also be fun.
I do think that a part of this will be running the most used parts of my station on solar (with battery backup, of course) hopefully on solar power, even through the winter. I may have to switch parts of it on mains power in the poorest sunlight conditions. The really power hungry parts, like big linear amplifiers will be running on mains power in any case, but they will not be running a lot in any case.
Using only the IC705 in December I have been able to get the battery up to 80%, but that has been with saving the time I was using it.
