Things have been very quiet here on the radio front of late. With the recent storms of Ciara and Dennis passing over, I lowered my vertical antenna for 28 MHz to avoid any damage.
On Monday the 17th of February, I put the antenna back up again as Storm Dennis moved away and I heard just one station - ZS6BUN in South Africa.
There was no sign of any Sporadic-E signals from Europe, just ZS6BUN on his own with about 4 decodes.
The Solar Flux was down at 71 with no visible sunspots on the sun. We are still well and truly in the solar minimum and I think it's going to take another six months before we see any real change.
NASA’s MAVEN Explores Mars to Understand Radio Interference at Earth
From a NASA press release...NASA’s MAVEN (Mars Atmosphere and Volatile EvolutioN) spacecraft has discovered “layers” and “rifts” in the electrically charged part of the upper atmosphere (the ionosphere) of Mars. The phenomenon is very common at Earth and causes unpredictable disruptions to radio communications. However, we do not fully understand them because they form at altitudes that are very difficult to explore at Earth. The unexpected discovery by MAVEN shows that Mars is a unique laboratory to explore and better understand this highly disruptive phenomenon.
“The layers are so close above all our heads at Earth, and can be detected by anyone with a radio, but they are still quite mysterious,” says Glyn Collinson of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, lead author of a paper on this research appearing February 3 in Nature Astronomy. “Who would have thought one of the best ways to understand them is to launch a satellite 300 million miles to Mars?”
At Earth, the layers form at an altitude of about 60 miles (approximately 100km) where the air is too thin for an aircraft to fly, but too thick for any satellite to orbit. The only way to reach them is with a rocket, but these missions last only tens of minutes before falling back to Earth. “We’ve known they exist for over 80 years, but we know so little about what goes on inside them, because no satellite can get low enough to reach the layers,” says Collinson, “at least, no satellite at Earth”. At Mars, spacecraft such as MAVEN can orbit at lower altitudes and can sample these features directly. MAVEN carries several scientific instruments that measure plasmas in the atmosphere and space around Mars. Recent measurements from one of these instruments detected unexpected sudden spikes in the abundance of plasma as it flew through the Martian ionosphere. Joe Grebowsky, former MAVEN project scientist at NASA Goddard, immediately recognized the spike from his previous experience with rocket flights through the layers at Earth. Not only had MAVEN discovered that such layers can occur at other planets than Earth, but the new results reveal that Mars offers what Earth cannot, a place where we can reliably explore these layers with satellites.
“The low altitudes observable by MAVEN will fill in a great gap in our understanding of this region on both Mars and Earth, with really significant discoveries to be had,” says Grebowsky, a co-author on the paper.
MAVEN observations are already overturning many of our existing ideas about the phenomena: MAVEN has discovered that the layers also have a mirror-opposite, a “rift”, where plasma is less abundant. The existence of such “rifts” in nature was completely unknown before their discovery at Mars by MAVEN, and overturns existing scientific models which say they cannot form. Additionally, unlike at Earth where the layers are short-lived and unpredictable, the Martian layers are surprisingly long-lived and persistent.
The Solar Wind is constantly streaming out from the Sun and can have a huge impact on radio propagation.
The In Our Time programme on BBC Radio 4 is hosted by Melvyn Bragg and covers various topics with a panel of experts. Recently they covered the Solar Wind.
Melvyn Bragg and guests discuss the phenomenon behind the auroras at Earth's poles, the stream of charged particles spreading out from the Sun to the border of the solar system.
Mon 3rd Feb 2020 - This was was unusual because I didn't hear one single FT8 signal on 28 MHz for the whole day. I nearly always hear something every day but Monday the 3rd was a complete blank.
Tues 4th Feb 2020 - Due to a Windows update, I didn't start listening until about 12 noon but I'm not sure if I missed much anyway.
Just before 13:00, I heard one lone signal from South Africa.
At the end of 2019, there were 63,070 amateur radio licence permits in Germany, a drop of 1,406 or 2.2% on the figure of 64,476 for 2018.
As can be seen from the chart above, the numbers have been in decline for some time and are down about 12% in the last decade.
The chart below shows the number of people taking the amateur licence test every year.
Even allowing for a high pass rate, the numbers are well below what is needed to stop the overall decline.
As one of the largest countries in Europe, the figures from Germany are significant and are probably reflect what is happening in other European countries as well.
After a very quiet week, there was a modest Sporadic-E opening on 28 MHz on Saturday the 1st of February 2020. In total, 36 stations in 8 countries were heard.
There was also a shorter opening to Germany and Poland on Friday the 31st of January but it was hardly worth mentioning.
The solar flux is at 74 which is still really too low to allow any kind of F2 propagation on 28 MHz at this latitude.
This 39 minute talk about Amateur Television was given at the Cardiff Microwave Roundtable in the Spring of 2019 and it has just been uploaded to YouTube.
It gives a good summary of the current state of Amateur TV in the UK and the techniques and frequencies used.
The RF10 is an old type of Czech military radio operating on FM with 400 channels from 44.000 to 53.975 MHz. The output power is supposed to be just over 1-watt.
The RF output is via a socket for a whip / long wire antenna (shown above on the far left) or via the BNC socket alongside it.
While it does not cover the new 40 MHz 8-metre band, it may be of interest to those listening on the low VHF frequencies or anyone on the 50 MHz / 6-metre band.
There are a large number of commercial and utility companies making use of the low VHF band in the USA from 30 to 50 MHz. Several manufacturers including Kenwood sold radios to service this market.
In the past, these were largely operating on FM but many systems are now being replaced with their digital equivalents. As a result, many old Kenwood commercial FM transceivers can be picked up on sites like eBay.
These radios are a potential source of relatively cheap FM radios for the 40 MHz (8-metre) band.
It should be noted that commercial radios are usually programmed to operate on certain frequencies. Any second hand models will need to be re-programmed.
Here are the Kenwood radios that operate on the Low VHF band. * * * * *
Kenwood TK-190... This handheld radio comes in two versions. The TK-190K covers 29.7 to 37.0 MHz and the TK-190K2 covers 35.0 to 50.0 MHz. Both versions have an output power of 1-watt (Low) and 6-watts (High).
This radio had a list price of $643 in 2007.
* * * * *
Kenwood TK-630... This radio was released in the early 90's.
It is available with power output levels of 110 watts on FM! The TK-630 is available in three frequency ranges... 29.7 MHz to 37 MHz, 35 MHz to 43 MHz and 41 MHz to 50 MHz.
The Winter 2019/2020 edition of ECHO IRELAND is now available for IRTS members to download in PDF format. Any member wishing to change from the print version to the electronic PDF format should contact the Membership Records Officer... www.irts.ie/officers
In an effort to reach out to more people, the American Amateur Relay League (ARRL) have produced a new magazine aimed at beginners and those new to the hobby.
There are a number of interesting articles in it including a simple ground quarter wave ground plane antenna for 144 MHz and 432 MHz as well as a multi-band HF antenna.
From what I understand, the first one is free and future issues will be only for ARRL members.
RADMOR are a Polish company who manufacture radio transceivers for the commercial and military markets. One of their products, the Mobile Radiotelephone 3005 operates at 40 MHz.
To be more precise, the 3005-40 model comes in two variants... one can operate from 30 MHz to 41 MHz and the other one can operate from 40 to 52.5 MHz.
According to the specs, it has up to 32 channels max which suggests that it is designed to be used for a specific purpose i.e. operate on a fixed number of channels. It's not really suitable for say scanning the low VHF spectrum to see what can be heard.
It operates on FM and there is a choice of 12.5 or 25 kHz spacing. The power output is 5 to 10 watts.
The specs also say the current consumption on receive is 3.5 amps. This is 42 watts! It's very likely that it is the power consumption while transmitting.
More info about the radio can be seen on the company website HERE
I suspect that the company may only be interested in selling to companies rather than individuals but I like to keep a list of any 40 MHz equipment on the site.
The American Radio Relay League (ARRL) has announced it hopes to introduce a number of low cost kits in an effort to spark some interest in amateur radio.
ARRL is developing low-cost (target $5.00), build-it-inan-hour receiver and transmitter kits. We intend to make these available at nominal cost to members and radio clubs who want to have a different “soldering experience” at their next hamfest.
In a world of smartphones and social media, the thought of talking to someone in another country over a radio is no longer the novelty that it once was.
Building kits and actually getting something to work may well appeal to a lot of people and they get to learn something in the process.
Considering the size of the ARRL, it's likely that these kits may well prove to be very popular and widely available in time. At a $5 price point, they are likely to be very basic but at least it's a start.
28 MHz was wide open to Europe again today with loads of Sporadic-E signals on the band. Despite the fact that it's the middle of January, the band was as good as many days during the summer months.
The skip distance was slightly longer today compared to yesterday with not too many from the Netherlands making it through.
There were a few long distance stations heard which I assume were via double hop Sporadic-E but I guess you can never be too sure on 28 MHz. It's just possible some of the more southerly ones were via F2.
Two signals that stood out were LA5SJA way up in the north of Norway. I'd guess he must be in almost 24 hours of darkness at the moment. Also heard was R9XM deep into Russia.
After a quiet start, 28 MHz on Saturday the 11th of January 2020 sprang into life from the late morning on with plenty of Sporadic-E signals on the band.
In total, I heard 247 stations in 30 countries. The unusual ones were ZS6NL in South Africa, LU8YD in Argentina and K1CA and W2VW in the USA. The American ones were interesting as it's unusual to get East-West propagation this far north during mid-Winter at the bottom of the Solar Cycle.
The Solar Flux was at 74 which is up a bit on recent weeks, sign of the next cycle starting?
The European stations heard on 28 MHz are shown below. The best thing about FT8 is that it really shows if a band is open or not. It seems as if there is some sort of Sporadic-E on 28 MHz on most days even throughout the winter.
In the days before FT8 when we only had cw beacons to listen to, that really wasn't so obvious. You could look at the text books and read that there is a Summer Sporadic-E season with a mid-Winter peak. It looks are if it never really dies away, even in the depths of Winter.
Peter, VK3YE recently posted a video on YouTube about some oblong loop antennas for 28 MHz and 50 MHz.
What attracted my attention to it was the simplicity of the antenna and it has some notable features...
1) Ease of Construction... As you can see from the diagram on the left, the 50 MHz version is only 1-metre wide and the 28 MHz version is 1.8-metres wide.
It's not hard to imagine using a horizontal non-conductive support that wide and then effectively hanging the whole structure from something like a PVC mast or even the branch of a tree.
2) Simple 50 Ohm feed point... Most loops in the shape of squares or triangles seem to have an impedance around 100 ohms and require some sort of matching device.
This oblong loop seems to have a lower impedance and is closer to 50 ohms. As a result, it can be fed directly with 50 Ohm coaxial cable. It would however be probably worth making a few loops in the coax at the feed point to make a choke balun.
3) Cost... The antenna can be made with bits of PVC pipe and some wire. It should be very cheap to make.
If you want to get on say 50 MHz then this oblong antenna would be way better than some sort of commercial vertical covering 6m, 2m and 70cms. It should also be way better than some HF antenna like a G5RV or similar that it pressed into service. In terms of bang for buck, something like this is hard to beat. You'll need to get it up high though.
Have a look at VK3YE's video below and you'll get a better idea of what it's like.
Thursday the 9th of January 2020 wasn't the best of days on 28 MHz. In the morning, there was an opening to the Nordic countries while there was a short opening to N Italy and Slovenia in the late afternoon.
The one unusual signal was ZS6LKF from South Africa.
While Tuesday the 7th of January 2020 was pretty quiet on 28 MHz, the Sporadic-E propagation made a return on Wednesday the 8th of January with plenty of signals being heard on the band.
The only unusual signals were from southern Russia. These were either double hop Sporadic-E or possibly one hop F2.
According to PSKReporter, I uploaded 231 reports from 26 countries on 28 MHz on the 8th of January 2020.
The Solar Flux is at 72 which up a bit on recent weeks but is still very low.
There was a pretty good mid-Winter Sporadic-E opening on 28 MHz on Monday the 6th of January 2020. As can be seen from the map above, I heard plenty of PA stations from the Netherlands at about 1,000kms suggesting a reasonably high MUF. That seems to have been the case as others reported that 50 MHz was open as well.
There wasn't much in the way of DX but nice to see some activity on the band all the same, especially at the bottom of the sunspot cycle.
