Thursday, October 31, 2019

Opening on 28 MHz - Wed 30th Oct 2019


The 30th of October was one of those days when I could hear some weak FT8 signals coming from the loudspeaker of the radio and not really strong enough to take much notice of them.

It was a bit of a suprise to see later that the band had been open to Africa and South America during the day

Wednesday, October 30, 2019

Local experiments on 23cms...


Every Tuesday evening, we have a local VHF net in Cork and a few of us get together for a chat. We use the the 6m, 4m, 2m and 70cms bands and which one we use depends on which Tuesday of the month it is.

It usually covers the first four Tuesdays of the month and if there happens to be a fifth Tuesday then we gave it a skip. A few weeks back, we thought it might be a good idea to use the fifth Tuesday in a month for experimentation, to try something that we don't usually do.

From this concept came the idea to try the 23cms band, i.e. 1296 MHz.

Denis, EI4KH near Watergrasshill has a Yaesu FT-2312 23cms transceiver running 4 watts on FM only and his antenna is a 26 element Yagi horizontally polarised.


A sked was organised with Don, EI8DJ who was located in a car at Camden near Crosshaven at the mouth of Cork harbour, a distance of 22 kms or 13.8 miles.


While the path wasn't line of sight, both Denis and Don were in good high locations. EI4KH was about 120m above sea level while EI8DJ was at a spot about 45m above sea level.

As the plot shows below, any obstructions on the path were several kms distant which made them less of an obstruction.


For EI8DJ's portable set-up, he was using a scanner for receive with a home made Bi-Square antenna shown below which was sitting on the dash of his car.


Using a frequency of 1290.000 MHz, EI8DJ managed to hear the FM signal from EI4KH at an estimated S'4' signal strength and a successful 23cms to 2m crossband contact was completed.

EI8DJ found the Bi-Square to be suprisingly directive and later peaked the FM signal from EI4KH to a maximum of an estimated S'7' signal strength.

The experiment was repeated with EI8DJ back in his driveway which is some bit lower than his portable location. From his home location, EI8DJ couldn't hear any sign of the FM signal from EI4KH.

While the distanced achieved were nothing special, it was interesting to see some local activity on the lowest of the amateur microwave bands.

Notes:
1) The beam heading for Denis was 170 deg.

Saturday, October 26, 2019

Sporadic-E opening on 28 MHz - Fri 25th Oct 2019


Even though it was late October, there was a Sporadic-E opening on 28 MHz from around Europe.

As can be seen from the map, the band opened up via Sporadic-E to Spain and probably linked up with some F2 propagation down to South Africa.

There were some signals from Eastern Ukraine and SW Russia as well. There were possibly F2 but I'd be inclined to think they were double hop Sporadic-E.

Even though we are at the bottom of the sunspot cycle, the band isn't completely dead.

Monday, October 21, 2019

The remarkable rise of FT8

I came across a news item recently with a chart showing the remarkable rise of FT8.


The data for this chart came from the ClubLog system which is used by thousands of people so I would assume it gives a reasonably representative picture.

Saturday, October 19, 2019

Conditions on 28 MHz - Sat 19th Oct 2019


An interesting day on 28 MHz. Even though the solar flux was way down at 66 and we're at the sunspot minimum, it does show that the 28 MHz band isn't completely dead at the moment.

While none of the signals were particularly strong and most were buried in the noise, the band was open. Over the last few days, there have been openings as well so it's worth checking the band.

Monday, October 14, 2019

Signs of the next solar cycle starting...

Courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.

At the moment in October of 2019, we are the bottom of the sunspot cycle and conditions on the HF bands are pretty awful. Recent observations of the Sun however show that things are changing.

The image above shows the active regions of the Sun's corona, the outer atmosphere of the Sun. Active regions, solar flares, and coronal mass ejections will appear bright here.

On the 6th of October, two regions with different magnetic polarity were spotted which are part of the next solar cycle.

Back in April, I had a post about a report from NOAA/NASA which said that the end of Cycle 24 and start of Cycle 25 will occur no earlier than July, 2019, and no later than September, 2020. The latest observations tie in with this report.


These observations don't mean that conditions on the HF bands are going to improve all of a sudden. This is a slow process. Over the next year or so, we should begin to see more and more regions with the magnetic polarity of the new solar cycle 25 and fewer with the solar cycle 24 signature.

It's only after we have passed the solar minimum for sure that scientists can pinpoint exactly when it happened.

I would suggest that it will probably be late 2020 before we start to see any real enhancement in the HF bands. Even then, it will be a case of more openings on the likes of 21 MHz rather than 28 MHz.

Links...
https://sdo.gsfc.nasa.gov/data/

Saturday, October 12, 2019

Example of BBC TV signal at 45 MHz being heard in South Africa

The BBC recently released this old television clip from 1949 explaining how an amateur radio station in Cape Town, South Africa had received TV signals from the UK.



The map below shows the path which is about 9,700kms or 6,000 miles...


The TV transmitter mentioned in the video was a 405 line transmission from Alexandra Palace in North London. This was vertically polarised with a power of 500 kilowatts (ERP?).

This TV signal had a video carrier on 45.0 MHz and a sound carrier down at 41.5 MHz.

The reception report in 1949 was near the peak of solar cycle 18. As can be seen from the chart below, that was a really good sunspot cycle and conditions were probably excellent on all the HF bands and well up into the low VHF region.

The most likely mode of propagation at 45 MHz was probably multi-hop from the F2 layer in the ionosphere. The maximum usable frequency was probably above 50 MHz so the signals on 45 MHz should have been very good.

It's likely however that with a video signal spread out over three and a half megahertz, the picture was probably very distorted and constantly changing. It should have been possible however to have very good reception of the sound on AM on 41.5 MHz with a dedicated radio receiver.

The radio contact shown in the clip between G8IG in England and ZS1PK in Cape Town, South Africa was probably on 28 MHz AM (note the beam at the start of the clip).

The South African station mentioned that signal were better when things were calm which might infer some sort of tropo ducting. That is unlikely to have been the case as it was very probable that all propagation was via the ionosphere and the weather conditions would have no impact.

All the same, it's an interesting example of early low band VHF TV reception.

Saturday, October 5, 2019

Video: 144 MHz moonbounce with 200w and a 9 el Yagi


In a 45 minute video presentation, KC1HTT in the US shows how it is possible to make contacts on 144 MHz by bouncing signals off the moon with 200 watts into a 9 element Yagi.

Link HERE

The complete station and project is costed at $5,000 but many people will have parts of the station anyway for their 2m SSB station.

The video is a good introduction into what is required to try moonbounce on 2 metres.

Thursday, October 3, 2019

Conditions on 28 MHz - Wed 2nd Oct 2019


I left the radio listening to the FT8 frequency on 28 MHz yesterday and I was suprised to see there had been a reasonable opening. Not too bad considering that the solar flux is down at 69 and we're hopping along the bottom of the sunspot cycle.

As per usual, the main workhorse here is Sporadic-E as can be seen from all the European signals. This allowed me to hear DX signals that were reaching the latitude of Spain.

i.e. F2 prop from say Chile to the Azores and then Sp-E to Ireland.

Saturday, September 28, 2019

Tropo path opens on 2m from the UK to Cape Verde Islands - Sat 28th Sept 2019


Just a quick post to say that D41CV in the Cape Verde Islands managed to work G7RAU in the SW of England on FT8 on 144 MHz this morning, Saturday 28th Sept 2019.

The tropo forecast doesn't look great at the northern end of the path but it might be worth checking.

See F5LEN's website.

Thursday, September 19, 2019

Opening on 144 MHz from the Azores results in several contacts over 3,000kms

On the evening of the 14th and the morning of the 15th of September 2019, there was a very good tropo opening on 144 MHz from the Azore Islands in the Atlantic Ocean to parts of the UK, France, Netherlands, Belgium and Germany.


A list of the stations worked by José CU3EQ using the digital FT8 mode is shown below...

Saturday 14th September 2019
20190914 18:30 G7RAU IN79JX JT65 -18 -10 2138km
20190914 18:47 G4LOH IO70JC FT8 -02 +01 2145km
20190914 18:54 F6DBI IN88IJ FT8 -16 -16 2193km
20190914 19:47 ON4KHG JO10XO FT8 -24 -16 2768km
20190914 20:39 F6KHM IN78RJ FT8 -20 -21 2107km
20190914 20:46 GW0KZG IO71LW FT8 -16 -09 2257km
20190914 22:12 G4RRA IO80BS FT8 -19 -23 2263km
20190914 22:15 G4KWQ IO92AQ FT8 +03 +05 2480km
20190914 22:49 M0JDK IO93KH FT8 -24 -19 2563km
20190914 22:57 G8VHI IO92FM FT8 -19 -21 2496km
20190914 23:17 M0CGL JO03BF FT8 -11 -19 2632km
20190914 23:19 G0GMB IO92NB FT8 -21 -19 2513km
20190914 23:20 PA2M JO21IP FT8 -14 -07 2852km
20190914 23:24 PA3FYC JO31AF FT8 -23 -21 2927km 
20190914 23:27 ON8KW JO20BW FT8 -14 -16 2790km
20190914 23:28 G4FUF JO01GN FT8 -19 2579km
20190914 23:49 PA3BIY JO22HB FT8 -24 -16 2861km

Sunday 15th September 2019
20190915 00:06 DJ6AG JO51EQ FT8 -22 -15 3231km ODX of all
20190915 00:08 G3NJV IO70JA FT8 -09 -16 2141km
20190915 00:45 ON4GG JO20AR FT8 -08 -05 2777km
20190915 00:59 PA2M JO21IP FT8 559 559 2852km
20190915 06:53 ON4IQ JO20AR FT8 -24 -04 2777km
20190915 07:10 DG1KDD JO31LE FT8 -22 -20 2988km
20190915 07:15 M0CKM IO90QT FT8 -17 -10 2472km
20190915 07:25 DF2ZC JO30RN FT8 -16 -17 3006km
20190915 07:26 ON4PS JO20KQ FT8 -12 -06 2832km
20190915 07:33 PA0JMV JO21PM FT8 -09 -13 2886km
20190915 07:34 PA5Y JO21VO FT8 -18 +04 2922km
20190915 07:35 PA3CMC JO21WI FT8 -19 -12 2920km
20190915 07:40 ON4LDP JO10UN FT8 -21 -15 2749km
20190915 07:44 G8BCG IO70RK FT8 +01 +00 2204km
20190915 08:00 PA2CHR JO32DB FT8 -15 -20 2970km
20190915 08:06 M0AFJ IO70IC FT8 -13 -03 2140km
20190915 08:36 DK4TG JO31LB FT8 -15 -21 2984km
20190915 08:54 DF1JC JO31OG FT8 -22 -11 3007km
20190915 09:12 DF6PW JO40AQ FT8 -17 -08 3049km
20190915 09:13 DL6YBF JO31OX FT8 -17 -06 3027km
20190915 09:23 PA3PCV JO20VV FT8 -24 -18 2901km
20190915 09:44 PA4EME JO20WX FT8 -17 -02 2909km

This is a more detailed view of the stations worked...

Wednesday, September 18, 2019

US Government Report on 32-42 MHz from 1998

Thanks to Rob, PE9PE who sent on an interesting link recently about a US government report about the low VHF spectrum from 32 to 42 MHz.

After a bit of research, I established that the report titled "NTIA Special Publication 98-36 SPECTRUM REALLOCATION REPORT" was from February 1998.


The report looked at who the existing users were in this part of the spectrum and whether some of the frequencies could be reallocated to commercial interests.

While the full report looked at several different bands, we'll concentrate on the low VHF spectrum here.


I have included sections of interest from the report below with certain key points highlighted in bold.

It might be worth pointing out that antennas for low band VHF tend to be very large compared to those for the higher VHF and UHF bands. For example, a full size quarter wave ground plane antenna is roughly 2.5 metres on 30 MHz and 2 metres on 40 MHz.

While the report is over 20 years old, it does show that even back then there was little commercial interest in the 30 to 50 MHz spectrum.

*****
SECTION 3 ASSESSMENT OF REALLOCATION OPTIONS
INTRODUCTION In the previous section, the bands to be considered for reallocation for non-Federal use were identified. All of the bands being considered for reallocation are used by the Federal Government agencies, in varying degrees, to support Presidential and Congressionally mandated missions. A band-by-band assessment of these factors is presented and recommendations are made as to which bands will be included in the spectrum reallocation plan.32-33, 34-35, 36-37, 38-39, AND 40-42 MHz 

Band Usage 
The Department of Defence (DoD) uses the frequency bands between 32-42 MHz for tactical communication using the Single Channel Ground and Airborne Radio System (SINCGARS) and other land mobile radio (LMR) assets (e.g., Scope Shield II) as well as some non-tactical intra base radio functions.

Friday, September 13, 2019

Watch out for VHF path to Cape Verde Is

Just a note to say that there is a nice high pressure system over the eastern part of the Atlantic at the moment and there is a possibility of a VHF opening to Cape Verde Islands from the UK and Ireland.

As always, it's a long shot but keep an eye on the tropo prediction website of F5LEN.

Wednesday, September 4, 2019

Tom EI4DQ completes an 11 band DXCC!


Congrats to Tom EI4DQ who recently achieved an 11 band DXCC!

While a number of EI stations have 10 band DXCC, Tom is the only one to get the magic 100 countries confirmed on eleven bands.


The key difference of course is that EI4DQ has managed to get DXCC on 144 MHz (2 metres) as well primarily by bouncing signals off the moon.



It's probably no exaggeration to say that it's easier to get an 8 band DXCC from 10m-80m than it is to get DXCC on 2m!

Here is an excerpt of Tom's 11 Band DXCC journey....

On the 21st of August 2019, I finally completed my 11 band DXCC.

I had started my plan of trying to gain the 11 band DXCC goal back in March of 2015, after completing DXCC for the 2 metre and 6 metre bands. I decided it was time to try and get DXCC on the HF bands as well. 

The last time I had operated the HF bands was back around 1998. I installed various antennas for all the hf bands i.e. dipoles, verticals, loops, etc. I decided to start at the bottom i.e. 160mtr band (1.8 MHz), and work my way up to 10mtr (28 MHz).

My first 160mtr antenna was a single wire inverted L. It worked ok but I had lots of issues feeding it at the base as it had a very low impedance. I always had to use some type of tuner at the base to feed it and make it work. 

I then made a folded Marconi L antenna out of 450 ohm open wire feeder, i.e. 4x impedance transformation. Wow what a difference! 



Direct 50 ohm feed, no tuner, 1:1 vswr, and hearing and working DX much better. I also had about 60 radials down of various lengths.

I started to listen to all the 160mtr contests picking off needed DXCC both on cw and ssb and then on FT8. I also started monitoring the Reverse Beacon Network, and the DXsummet DX cluster  for any new DXCC countries that were about. I was about to install a separate receive antenna for 160mts in late 2017, but when I purchased a ICOM IC7610, its noise reducing capabilities and receive were so good that I did not need any receive antenna. I completed DXCC on 160mtr in late February of 2019. 

80mtr / 40mtr / and 30mtr DXCC were all completed by March of 2019. 20mtr and 17mtr were completed by April of 2019. 15mts was completed in June of 2019 and 10mtr was completed in July of 2019. 

All contacts were confirmed via Logbook of the World (LOTW). I could have used some of my QSL cards from previous activity in the 1970's to 1990's period when I was very active on the HF bands but chose not to do so. I also tended to only pick out stations who were in the LOTW program.

The last band 12mtr (24 MHz) was completed in August of 2019. This band was the most frustrating band to work DX! It was a pain to hear DX on 15mtr and 10mtr and sweet nothing on 12mtr. It took me 2 months just to dig out the last needed DCXX to make 100 on this band. My final total on this band was 112 DXCC but only 100 of them uploaded to LOTW. 

So at last on the 21st of August 2019, the 11 band DXCC was completed. All together it took me just over 4 years to complete the needed HF DXCC.

All my antennas are homebrew vertical dipoles, loops or verticals, modes used cw / ssb / ft8.

Now its back to 6mtr, 4mtr and 2mtr! ... Tom, EI4DQ

Monday, September 2, 2019

Study suggests 11 year Solar Cycle is “Powered By Tidal Forces of Venus, Earth, Jupiter”


I recently across this news item based on a scientific paper which was released in May of 2019. Despite the huge differences in size, the study suggests that the planetary alignment of the planets Venus, Earth and Jupiter is large enough to effect the sun and its sunspot cycle.

"As with the gravitational pull of the Moon causing tides on Earth, planets are able to displace the hot plasma on the sun’s surface. Tidal forces are strongest when there is maximum Venus-Earth-Jupiter alignment; a constellation that occurs every 11.07 years."

The lead author of the study, Frank Stefani is quoted as saying...“There is an astonishingly high level of concordance: what we see is complete parallelism with the planets over the course of 90 cycles.”

If it is true then perhaps it might allow for better computer models to be built to predict future sunspot cycles?

Not only is the solar cycle of interest for radio propagation but it is hugely relevant to the large number of satellites in orbit in terms of drag and radiation.

More info on the study in the links below...

1) Scientific Paper... A Model of a Tidally Synchronized Solar Dynamo
2) Daily Galaxy... Sun’s 11-Year Cycle –“Powered By Tidal Forces of Venus, Earth, Jupiter”
3) Newsweek... SUN'S SOLAR CYCLE IS GOVERNED BY THE ALIGNMENT OF THE PLANETS, SCIENTISTS DISCOVER

Sunday, September 1, 2019

Failure of a $14,000 antenna project


I came across this website recently which I think some readers might find of interest. It's a story of one persons antenna project in the USA which cost $14,000 and its eventual failure.

You can read it here... http://w6dsr.com/LP1005AA/index.html

Friday, August 30, 2019

French aeronautical threat to 144 MHz band removed



For the last few weeks, there has been plenty of discussion about the French proposal to try and share the 144-146 MHz amateur radio band with 'aeronautical services'.

It was announced today that this threat has now been removed at a CEPT meeting in Turkey. This happened "in parallel to a number of other proposals being adopted to support aeronautical interests."

While this is good news, it is surely a wake up call that no amateur radio band can really be considered safe and the various national and international amateur radio associations need to be ever vigilant.

Wednesday, August 28, 2019

FCC petitioned to open up 45 to 50 MHz for DRM+ broadcasts in the USA


Currently most of the terrestrial radio stations in the USA broadcast either on the AM band from 540 to 1700 kHz or on the FM band from 88 to 108 MHz. At the end of September 2018, the FCC announced that there were 4,464 stations on AM and 10,867 stations on FM [1].

Due the crowded nature of the existing bands, it has been hard to introduce new digital radio formats.

DRM or Digital Radio Mondiale is a digital format designed to replace existing AM transmissions with clearer audio and with just 20% of the power. DRM+ is the format for VHF.

WRNJ Radio co-owner Larry Tighe has now filed a petition for rulemaking with the FCC, asking that the 45 MHz to 50 MHz band on the VHF spectrum be reallocated for DRM+ transmissions.

In a statement, Tighe said... “The 45–50 MHz band was allocated to two-way radio users in business and government, who have since migrated to higher bandwidths where they can use handsets with smaller antennas. As a result, this spectrum is extremely quiet right now. WRNJ monitored this bandwidth for an extended period of time, and heard very few distant signals.”

“There were 660 TV stations between Channels 2 and 7 before the transition to UHF for HDTV. There are now only approximately 60 TV stations in the USA on those old VHF channels. There is plenty of spectrum to share with a new service, i.e., DRM+ or any modulation, if the FCC really wanted to move AMs.”

Even though the DRM standard has been around for over a decade, it is only recently that it has begun to make serious inroads to the broadcasting scene with India, China and Russia showing an interest. One of the current problems is the high cost of DRM receivers which is prohibitive to consumers in developing countries.

Obviously if the USA opted for a new DRM+ allocation, it would give the format a huge boost. If it turned out to be the 45 to 50 MHz allocation then it raises the possibility of long distance reception by means of Sporadic-E during the summer months or via F2 propagation around the peak of the sunspot cycle.

More info in the links below.

Links...
1) FCC stats for the number of AM and FM stations at the end of Sept 2018
2) https://www.radioworld.com/tech-and-gear/u-s-based-shortwave-broadcasters-eye-digital
3) Previous post - Russia proposes to use DRM on 65.9-74.0 MHz

Video about contest station W3LPL



W3LPL in Maryland is a well known contest station and it's hard to miss the strong signal when they are on the HF bands.

I came across the video shown above which a 21 minute tour of the antenna farm.

Even if you have not into contesting, it's still interesting to see what is required for a high performance station.

Tuesday, August 27, 2019

ARRL prohibit automated contacts for Contests and Awards

I came across this news item from the American Radio Relay League a few days ago...

ARRL Contest and DXCC Rules Now Prohibit Automated Contacts
08/19/2019
Following the direction of the ARRL Board of Directors, ARRL has incorporated changes to the rules for all ARRL-sponsored contests and DXCC, prohibiting automated contacts. These changes also apply to the Worked All States (including Triple Play and 5-Band WAS), VHF/UHF Century Club, and Fred Fish, W5FF, Memorial awards. The changes are effective immediately.

A resolution at the July ARRL Board of Directors meeting pointed to “growing concern over fully automated contacts being made and claimed” for contest and DXCC credit. The rules now require that each claimed contact include contemporaneous direct initiation by the operator on both sides of the contact. Initiation of a contact may be either local or remote. 

I found this of interest because it shows the impact machine generated modes like FT8 and FT4 are having on amateur radio. As technology advances, it is challenging what peoples perception of what 'radio' actually is.

Some will argue that automation is nothing more than two computers talking to each other without any human input. Others and I'd suggest newer users may see very little difference between an automated system and having someone just click on a mouse to initiate a contact and then having the computer do the rest.

Hence the tongue in cheek graphic! 😉

Despite the ARRL ruling, I'd suspect we haven't heard the last of automation and automated contacts.

Addendum :
1) Some interesting thoughts by AE5X on the subject on this blog post.
2) Some thoughts on the subject by John, MW1CFN in this blog post.