Sunday, December 4, 2022

Communication experiments in Japan at 5600 MHz and 10 GHz using the ICOM IC-905


On the 17th of November 2022, ICOM staff in Japan conducted some experiments over a 25km obstructed path on the 5.6 GHz and 10 GHz microwave bands with the company's new IC-905 transceiver.

The photo above shows the view from the roof top of the six story building at ICOM's headquarters in Osaka. The two parabolic dishes for 5.6 GHz and 10 GHz are beaming towards the Ikoma mountains. The RF module of the IC-905 and the 2.4 GHz to 10 GHz transverter are also shown. The station at ICOM HQ was JK3AZL.

The second portable station JL3ZAB with a similar setup was operating from a hill near Kizugawa City which was about 25kms away on the other side of the Ikoma mountains. The map below below shows the path in Blue. The important point here is that both stations were blocked from each other by the mountains but both were line of sight to Mt Ikoma.

Both stations started early in the morning, setting up their radio equipment and antenna systems. By 9am, both stations were able to easily catch each other's signals by pointing their parabolic antennas at the summit of Mt Ikoma using a map and compass and were able to communicate by voice on both the 5.6 GHz and 10 GHz bands.

It is believed that the propagation mode was knife-edge diffraction from the mountain peaks.

The power of the IC-905 is 2-watts at 5.6 GHz while the output power of the 10 GHz transverter is 1-watt.

The test was repeated later with JL3ZAB now operating from the ICOM Narayama Laboratory. From this lower location, the summit of Mt. Ikoma was now longer visible. They were barely able to communicate on 5.6 GHz with CW while communication at 10 GHz was not successful.

The path from ICOM HQ to their Narayama Lab is shown above in Red. The path profile is shown below albeit with an exaggerated vertical scale.


The ICOM team concluded... "It is known that in the SHF band or even higher frequencies, radio propagation gradually becomes more linear, similar to light. The Icom team thought it would be interesting to see whether communication will be impossible under non-line-of-sight conditions as in this case, or whether communication by mountain diffraction (Knife-edge effect), known as anomalous propagation, would be possible.

The experiment revealed that mountain diffraction phenomena occur even on mountains with relatively gentle peaks such as the Ikoma Mountains. Conversely, if the peaks are not visible, communication is difficult."


Analysis...
Once the ICOM IC-905 goes on sale, people that purchase it may well expect only line of sight contacts as that will be the mantra of most websites and commentators. With high gain antennas and weak signal modes, there will be many unusual paths like the example above.

In an urban environment, there may well be many reflections off objects like high buildings, water towers, masts, etc.

If you consider that tropospheric ducting often occurs more often at microwave frequencies then there are bound to be surprises for those who are interested in experimenting on these amateur bands above 1 GHz.

News source... https://www.fbnews.jp/202212/w_news03/

Thursday, December 1, 2022

40 MHz & 60 MHz Facebook Group now has over 500 members


Just a quick update to say that the 40 MHz & 60 MHz Group on Facebook now has in excess of 500 members. As the chart shows above, it has more than doubled in the last year.

The level of interest in two obscure experimental amateur radio bands in the low VHF spectrum has been a bit of a surprise to me. I initially thought the group would struggle to get to 100.

If you have a genuine interest in keeping up with the experiments and activity on the band then you can find the group here... https://www.facebook.com/groups/2897330140356898

Wednesday, November 30, 2022

40 MHz beacon in Denmark off air due to electricity costs


The OZ7IGY team in Denmark have announced that their 8m beacon on 40.071 MHz has been turned off due to increased electricity costs.

They write... "The 40 MHz, 2,4 GHz, 3,4 GHz, 5,7 GHz and 24 GHz beacons are all off air due to the increased price of electricity. It is currently impossible to say when they will be back on the air. 

OZ7IGY has an annual electricity bill of more than 20 000 DKK, equivalent to about 2800 EUR given normal electricity prices. Unfortunately Denmark is among the most expensive countries when it comes to the cost of electricity. But we are also looking for equipment support in our continuous strive to make OZ7IGY the best beacon in the world.

As of October 2022 the annual electricity cost will exceed 7000 EUR.  – 2022-10-17"

The beacons at 28 MHz, 50 MHz, 70 MHz, 144 MHz, 432 MHz, 1296 MHz & 10 GHz remain operational.

Annual sponsorship of one individual beacon for one year costs 1400 Danish Krone which is about €190.

OZ7IGY website... http://www.oz7igy.dk/

Sunday, November 27, 2022

Upgrade of WSJT-X software and the 40 MHz band


Just a post of some notes for my own benefit although others might find it useful as well.

Even when I wasn't updating the blog for the last six months, I was still using the radio in that I left it monitoring the WSPR frequency on 28.1264 MHz every day. The software I was using on the PC was WSJT-X with quite an old rev V2.0.1 which I think is from 2019?

I never really bothered updating the version I had as it decoded WSPR and FT8 signals fine. I know my old version didn't decode the 'new' FT4 mode but I wasn't too bothered about that.

I tried listening for some of the Irish 40 MHz beacons this morning. I managed to get two two successful decodes from EI1CAH on 40.16 MHz using the PI4 mode. I think this was via aircraft scatter.

The other beacon EI1KNH on 40.013 MHz uses several modes including FT8 so I had to be careful as I didn't want to 'hear' something on 40 MHz and have my PC upload it to PSKReporter as a 28 MHz signal.

The problem with my old version of WSJT-X and FT8 is that it doesn't support any 40 MHz operation. So I downloaded the latest version of WSJT-X from the Princeton University website... V2.5.4

It essentially looked the same when I ran it. From the default settings, it doesn't show 8m (40 MHz) as a band option.


Under 'File', I had to go to 'Settings...' and then click on 'Frequencies' as can be seen above.

There are loads of options here... I picked the one that was All mode on 24 GHz as I was pretty sure I wouldn't need it 😉

Then it's just a case of double clicking on it and changing the frequency. I chose 40.680 MHz... and then clicked ok.

When I went back to the main programme then, I had 40.680 MHz on 8m as a band option.


In the end, I didn't manage to any FT8 decodes from the beacon but I probably need to improve my antenna system.

At listen I can report any signals that I hear now.

Addendum... I finally managed to decode one FT8 transmission from EI1KNH which I think was from aircraft scatter again.

Saturday, November 26, 2022

Antenna upgrade for the GB3NGI 432 MHz beacon

The GB3NGI beacon transmits on 432.482 MHz on the 70cms band and it is located on the summit of Slieve Annora in County Antrim in the north-east of Ireland. The site is 500-metres above sea level and it's locator square is IO65VB.


It has as far as I know been operational since 2014 and beams to the south-east towards London.

The beacon keeper Gordon, GI6ATZ reports that the antenna system has now been updated...

GB3NGI 70cms Beacon: - The single 70cms yagi was replaced today (22nd Nov 2022) by a pair of Antenna- Amplifiers 9 ele yagis beaming NE and SE

This should improve the coverage quite significantly up to the NE and whilst in theory it should be at least a 3dB reduction in power to the SE my initial test here show a significant increase in signal strength - but then I am relatively close to the beacon!

The old antenna had suffered quite a bit of damage and I suspect the driven element assembly was full of water. 

Would appreciate signal reports with the new antenna system particularly from the NE but also from the SE to see if people notice any improvement/reduction in signal strength. 

The map above shows the location of the beacon and the new beam headings of 45 degrees (north-east) and 135 degrees (south-east). 

In the past, areas like Glasgow and Edinburgh were on the side of the old beam so the new system should result in a much stronger system.

The beacon has an RF output power of 20 watts and transmits JT65b on the even minutes and CW on the odd minutes in the following sequence: -

00:01 – 00:51 GB3NGI IO65VB in JT65b mode
00:52 – 01:00 GB3NGI IO65VB in CW
01:01 – 01:29 Plain Carrier
01:30 – 01:40 GB3NGI IO65VB in CW
01:41 – 02:00 Plain Carrier
The sequence then repeats

To decode the JT65b, tune the carrier to obtain a tone of 1500Hz with the receiver set to USB, and the dial frequency reading 432.4805. The JT65b will then be tuned in correctly.


The antennas used for the 432 MHz beacon are a pair of 9-element Antennas-Amplifiers Yagis designed and built by Goran YU1CF :- https://antennas-amplifiers.com/product/70cm-antenna/70cm-rear-mount-wideband-strong-yagi/

Additional information...

1) GB3NGI website

Wednesday, November 23, 2022

HF & VHF Ocean Radars - 26 MHz to 43 MHz

HF & VHF Ocean Radars - 26 MHz to 43 MHz

I received an email recently from Rob, PE9PE looking for the email address of Des, EI5CD to pass on some information about some unusual signals at the bottom of the 26 MHz band. I didn't have the email info but I thought the information would make an interesting post and I'm sure Des will see it as well.


The concept of Ocean Radars is quite simple... a radio pulse is sent out by a transmitter at the shoreline, some part of the signal is scattered by waves on the ocean and this is picked by a receiver back at the coast.

It's described as follows... "How it works: We measure ocean currents by emitting radio waves from shore-based transmitting antennas that travel along the ocean's surface. The radio waves are scattered by the rough surface of the ocean (ocean waves) and part of the scattered energy returns like an echo to a receiving antenna.  The received echoes contain information about the range, direction, and speed of the current in relation to the antenna location. Combining this information from two or more antennas allows us to construct surface maps of current speed and direction."

The ITU frequencies for these systems are as follows:

a) On the lower part of the HF bands, they are at 4.4 MHz, 5.2 MHz and 9.3 MHz.

b) On the higher HF bands, they are at 13.5 MHz, 16.1 MHz, 24.5 MHz and 26.3 MHz.

c) In the low VHF spectrum, they are at 39.2 MHz, 41.4 MHz, 42.2 MHz and 43.5 MHz.

My main interest here are the systems operating at 26 MHz and above and how they might be used as a propagation indicator. There may be more frequencies but these are the ones I am aware of for now.

Systems... There seems to be two main companies in this space.

1) CODAR OCEAN SENSORS from the USA have their SeaSonde system and their website is https://codar.com/


As their information document above shows, the antenna for this system is just a vertical whip. 

When someone mentions a 'radar system', I think most of us imagine some sort of huge antenna array with many kilowatts of RF power. From the information I could find, it seems that 50-watts is typical power level.

Some use a small array of vertical whips side by side which probably help focus the signal on a certain area but it's nothing too elaborate.

There seems to be examples of these located at quayside walls next to where the public are walking so the power density is low.

An example of what the CODAR signal sounds like can be found here (just click on the audio sample on the right)... https://www.sigidwiki.com/wiki/CODAR

2) The other company is HELZEL from Germany and their website is https://helzel.com/

This is an example of their WERA VHF system...

High resolution VHF WERA - ITU bands 39.2, 41.4, 42.2 and 43.5MHz
Characteristics:
Typical range resolution of 300m
Best for highest resolution current measurements up to 25km
Wave measurements for Hs >0.2m for ranges of up to 10km
These systems use very small antennas and short arrays
Best suited for mobile applications

This is a map of some of their systems operating in Europe as of Q4 2022...


They don't mention what frequency... HF or VHF... is used by each one of these locations but I'm sure many of you will be living near one and wondering what it is.

After Rob told me about these signals, I found one around 26.300 MHz. I found it best to listen on AM and have the filters as wide as possible. In my case, that was 12 kHz.

It sounds like a rapid ticking or clicking noise. If you could imagine say a clock ticking once per second then this radar system sounded something like 3 ticks per second.

I don't have a sample of it to include in this blog post but it's easy to recognise.

Video... This video about the SeaSonde system gives an overview of its purpose...



Propagation indicator... Can we make use of them? While it will be very difficult to identify the location of any individual ocean radar system, they can still be used as a sign that a band is open.

There are many instances of when 21 MHz is open and 28 MHz is dead or 28 MHz is open and 50 MHz is dead. At least these ocean radars give some warning of improving conditions on a frequency in between.

Low Band VHF... There seems to be a general assumption that low band VHF (30-50 MHz) is dead and most of the users have migrated to the higher UHF bands. This is one instance where low band VHF and it's particular wavelength has a useful application and niche.

Q. Do you have an ocean radar system operating near you? Let me know your location and it's frequency and I'll add it to the post for reference.

Wednesday, November 16, 2022

Video presentation on the QRP Labs QDX 5-watt Digital Transceiver


Four Days in May (FDIM) is an annual QRP convention that is held in Dayton, Ohio. A series of talks are usually given and for the 2022 event, there was an interesting presentation given by Hams Summers (G0UPL) about his new QDX transceiver kit.

This is a 5-watt radio for the 80m, 40m, 30m and 20m bands and is designed for digital modes like FT8. The basic kit currently retails for just $69 but there may be additional costs like import duties. It is still a very cost effective way of getting on the bands especially when you consider how many main brand radios costing $1000++ must be sitting on one frequency doing FT8 day after day.

Hans writes on his website... "QDX is suitable only for single tone FSK modes, which covers the majority of digital modes in use today. This includes everything in WSJT-X, JS8Call, some fldigi modes e.g. RTTY, Olivia and more. QDX is not suitable for on/off keyed modes such as CW because it does not have click-reducing RF envelope shaping; furthermore it is not suitable for phase shift keyed modes such as PSK31 or modes involving multiple concurrent tones such as WinLink,"


The QDX is supplied with the surface mount parts already on the PCB but some level of experience is still required to build and assemble this kit. I don't think it's for absolute beginners.


The power output versus the supply voltage is shown above. As the frequency is relatively low... 3.5 MHz to 14 MHz... the performance of the output stage is pretty good.

Hans did mention that there are plans for a similar radio covering 20m to 10m ...14 MHz to 28 MHz... and the challenge then will be to have a reasonable output at the higher frequencies.


Demand for this kit has been huge so check on the QRP Labs website for availability. There is also a lot more information about the radio on that site.

The presentation itself covers the basics of digital modes before exploring what is going on in the QDX radio.


The video of the presentation which was only put up on YouTube on the 14th of November 2022 is about an hour long but the audio level is very low. I had to use headphones to listen to it.

Sunday, November 13, 2022

Looking ahead to the ICOM IC-905 VHF, UHF & Microwave Transceiver


Back in the first half of 2022, I was following the progress of what was termed the 'ICOM SHF Project'. ICOM first announced this in December of 2021 and it suggested that they were developing a transceiver for the 2.4 GHz and 5.6 GHz microwave bands. See my earlier post HERE.

The blog post got a good deal of traffic and it was obvious that a lot of people were interested in this product even if was supposed to be for only two microwave bands.

I don't think many people had an idea earlier in the year just what ICOM had in the pipeline and it turned out to be pretty amazing.

In this post, I'll look at the new IC-905 in two parts. The first part is a summary and if anyone wants to look at the finer detail, that will be in the second half of this post further down.

In a future post, I'll look at the 10 GHz system.


Part 1 - The ICOM IC-905 in summary

The ICOM IC-905

At the Tokyo Hamfair in August of 2022, ICOM announced their new IC-905 radio which covers the following bands...
144 MHz (2m)
432 MHz (70cms)
1296 MHz (23cms)
2.4 GHz (13cms)
5.6 GHz (6cms)

They also have an optional transverter for 10 GHz (3cms).


As you can see from the photo above, it does have a similar appearance to the current IC-705 model which covers all of the HF, 6m, 2m & 70cms bands.

Note however that there is no RF in this part of the IC-905, it's just the control unit. The radio itself or at least the RF part of it is in the head unit which goes up next to the antenna.


This is part of the concept of putting the control unit indoors where the user is and putting the radio (RF) section up at the antenna. The 'LAN Cable' connecting the two will use PoE (Power over Ethernet) which will carry power and control signals up to the RF module as well as transferring the signals from the radio back down to the controller.

The main point here is to eliminate losses from coaxial cables running from the radio shack to the antenna. These can be really high at UHF and Microwave frequencies.

Some features of the IC-905 system...

1) The power output is 10-watts on 144 MHz, 432 MHz and 1296 MHz from a single N-Type connector. There is a separate SMA type connector for 2.4 GHz and 5.6 GHz and the power on those bands is 2-watts.

2) The controller has a 4.3 inch (11cm) colour display and as you might expect, a real time spectrum scope and waterfall display.

3) All the usual analogue modes like FM, SSB & CW as well as the D-Star digital mode which is standard for an ICOM radio.

4) One nice feature is ATV (Amateur TV) in FM mode.

5) One feature of huge importance is that the RF module will be frequency locked by GPS. This is a major shortcoming in several of the existing ICOM rigs on the market in that frequency drift on some digital modes on the UHF bands is a major problem. The GPS locking should help resolve this.

Price & Availability...

As of November 2022, ICOM have not announced a price for the IC-905. I suspect it will be in the $2000-$2800 price range but we'll have to wait and see.

As for availability, they haven't announced it. I suspect it will be the second half of 2023 before we see any units for sale.

Game Changer...

When ICOM released their IC-705 radio, there was huge interest in it despite it being a low power 10-watt radio. One of the key selling points is that it was a 'shack in a box' with all of the bands from 1.8 MHz to 432 MHz in one unit.

In a similar vein, the new IC-905 is very much a 'shack in a box' for the VHF bands and above. If ICOM had announced a new VHF/UHF radio with just 144 MHz, 432 MHz & 1296 MHz, there would be a lot of interest in it. The fact the IC-905 has 2.4 GHz and 5.6 GHz as well is pretty amazing.

I suspect the biggest change will be to the 1296 MHz or 23cms band. There is a serious lack of radios available for this microwave band and getting a separate radio for just one band is prohibitive.

Close up of the base of the Diamond X6000A

I can see a LOT of people buying Tri-Band type verticals made by the like of Diamond and Comet and using them with the new IC-905. I think it's going to generate a lot of activity on the 23cms band in urban areas in many parts of the world.

The thing about a radio like this is that it is really versatile. People may come up with new ways of using it that we haven't considered at the moment.

I can really see this radio being a game changer for the UHF and low microwave bands IF the price isn't too high.

***

Part 2 - The ICOM IC-905 in more detail

IC-905 Controller... Let's have a look at this is a bit more detail.


The image above shows the front of the IC-905 and you get some idea of the depth as well.


The photo above is of the front of the controller from the Toyko Hamfair last August.


The photo above shows the rear of the controller and again, you get some idea of the depth.


As you can see from the photo above, there is very little on the rear of the controller other than two heatsinks.

While the IC-905 uses a 12-volt supply, it seems likely that there is a much higher voltage going up the Power over Ethernet cable to the RF unit. It's likely that there is some type of switch mode power supply in the controller to generate this higher voltage and a reasonable heatsink is required for that. There are of course all of the low voltage supplies to all of the electronics in the controller as well and again, a heat sink aids in keeping things cool.


The image above shows the right hand side of the controller. 


The image above shows the right hand side in more detail. The port with the Green LED and the cable in it is the Power over Ethernet cable that goes to the RF module.


The image above shows the left side of the controller with the various ports.


The photo above is an actual photo of the left side of the controller.


And now onto the RF module. This image above gives an overview of the underside of the RF module. From left to right...

a) The cable on the left is Power over Ethernet LAN cable from the controller unit. 

b) The BNC socket has an RF output at 10 MHz which is controlled by a GPS unit inside the RF module. The 10 MHz signal reference from here is fed to the optional 10-GHz transverter and provides that unit with a stable frequency reference.

c) The connector on the right is for the CX-10G which is the optional 10 GHz transverter.



This image above is another view of the underside of the RF module. 


The image above is the top side of the RF module. All 2m, 70cms & 23cms signals are fed out via one N-type socket. Both the 2.4 GHz and 5.6 GHz bands have their own individual SMA socket. There is also a SMA socket for a small whip antenna for to receive GPS signals.


The image above gives another view of the top side of the RF module.


The image above shows the top side with the GPS antenna connected.


The image above is an actual photo of the RF module on display at the Tokyo Hamfair.

If we consider that a N-type connector is about 2cms in diameter then the dimensions of the RF module above is about 18cms across and 26cms in height. The depth is perhaps in the region of 8cms.


In terms of operation, the new IC-905 is basically the same as the popular IC-705.


This image above is a screenshot from the controller showing it operating on the 5.6 GHz band with a selection of modes.


The image above is a screenshot of the 11cm display showing a selection of menu items.


One amazing feature of this radio is it's ability to use ATV (Amateur TeleVision). In the above image, you can see a received ATV signal inset in the screen.


And this is the received signal on full screen.


ICOM also intend to sell omni-directional antennas for both the 2.4 GHz and 5.6 GHz bands.

I suspect third party antennas for these bands will be a lot cheaper.

Video... and finally, this is the promotional video from ICOM for the IC-905

That's it. I've done my best to collate all of the information available and put it in one spot. We'll just have to wait now until ICOM announce a release date and price.

Thursday, November 10, 2022

EI7GL Twitter account now has 1000 followers...

As the title of the post says, I recently passed the 1,000 followers mark on Twitter.

Just search for EI7GL there if you want to follow.

There are by the way just 7 amateur radio related Twitter accounts in Ireland (EI & GI) who have more than 1000 followers (...as of Nov 2022).

There are about 70 EI/GI accounts in total on that platform.

Tuesday, November 8, 2022

Successful Digital Amateur TV tests on the 29 MHz band across the North Atlantic - 7th Nov 2022

Back in December of 2021, I had a post titled "More information about the proposed Amateur TV experiments at 29.250 MHz & 51.7 MHz" up on the blog and it received quite a lot of interest.

On the 7th of November 2022, Rob M0DTS managed to send a TV signal on 29.250 MHz across the North Atlantic!


First off, some information. The map above shows the path... M0DTS is located in the NE of England and he was using an online Kiwi Software Defined Radio (SDR) which was located in the state of Pennsylvania.

Rob was transmitting his Digital Amateur TV signal on 29.250 MHz using 100-watts into a 3-element Yagi. The Kiwi SDR in the USA was using a simple loop antenna for reception of the signals. As the SDR was online, Rob was able to log in and see if his DATV transmissions were being received.


The initial tests were done on the 6th of November as can be seen from the screen capture above. 

On the left are the SSB signals the Kiwi SDR was receiving down around 28.5 MHz. On the right, you can see some FM signals up around 29.6 MHz. Rob's DATV signal can be clearly seen at 29.250 MHz.

M0DTS writes... "Been watching my 29.250MHz DATV test signal on a kiwisdr in Pennsylvania... there is hope! This was 66Ks DVB-S2, Lots of frequency fading but on peaks maybe it will just work in DVB-S2... I can also do DVB-T, but today was just gauging signal strengths."


There's a lot of information in that waterfall display if we examine it closely. First off, left to right is frequency and up and down is time.

The path for this experiment was about 5,500 kms in length and probably involved two hops off the F2 layer in the ionosphere. Sometimes the signals arrive in phase and appear strong, sometimes the signals are out of phase and cancel each other out.

As the DATV signal is spread out over 80 kHz, the higher frequency part of the DATV signal has a slightly shorter wavelength than the lower frequency and longer wavelength part.

What's fascinating is that you can see in the DATV waveform where the signal is being cancelled out. It starts at the higher frequency and as the conditions change over time, the 'notch' moves lower in frequency as the longer wavelength signals cancel out.

As you might imagine, losing big chunks of the digital video signal plays havoc with reception.

Back in the 'old days'.. say the 1970's and 1980's, there were times during the peak of the sunspot cycle when broadcast TV signals around 45-55 MHz were seen around the world. At the time of course, it was analogue TV but the F2 signals were noted for being highly distorted as different parts of the signal were missing.

Anyway, I digress :o)


On the 7th of November, Rob managed to successfully send an amateur TV signal across the Atlantic when the signals were stronger.

M0DTS writes..."Today's quick 10m test across the pond. Txing 18Ks DVB-S 2/3 -> receiving IQ signal output from kiwisdr into sdrangel then demodulated, note the kiwisdr has 20KHz bandwidth limitation. So DVB-S is possible over HF path when fading allows :-) "

In conclusion: On the face of it, sending a signal across the North Atlantic on the 10m band is no big deal. It has been done countless times on CW, SSB, FT8, FM, etc. 

It's not the same as say Slow Scan TV (SSTV) where a single image is sent over SSB. What makes this significant is that it's actual video. 

The amateur TV community have been experimenting for the last few years trying to compress television signals into smaller and smaller bandwidths. In the UK, they're been doing this at 71 MHz, at 146 MHz and the higher amateur radio bands.

With the improving conditions on the HF bands, experiments like this are now a possibility on bands like 29 MHz and perhaps in time at 51 MHz as the sunspot cycle improves.