SDR Console V3 analyser

The shack, finally operational after a few months off.

With the rebuild of my shack complete I’ve been able to start testing out all my radios, new connections etc.

The Mini-Circuits components all come well packaged in anti-static bags

A whole bundle of new cables from Mini-Circuits arrived last of all and have helped tidy up the back of the radio 19″ rack considerably. I’ve previously installed quite a few Mini-Circuits components, including 0.141″ diameter Hand-Flex interconnect cables, and so it was more of these that I opted for. The bonus with these cables is that they are hand formable meaning you can shape and bend them into pretty much any area that you want to. The 141 series (which I use) are capable of a 8mm bend radius, whilst the thinner 086 series can be bent to 6mm.

Being able to manipulate the cables certainly helps in tight spaces, and when you don’t want them to hang down

Previously I used hand-made cables with RG58U coax, but in order to have a 19″ rack that can slide out from under the desk, the cables needed to be longer than actually required. Because of this the cables would drop down into all the others attached to the PC and in some cases cause a little interference. With the Hand-Flex cables I’ve been able to use the same length of coax to allow me to move out the rack, but be able to bend them up and out of the way of the PC cables.

They’re also very good for the radios on the rack, being able to bend them and hold in place around the radios and other cables. They are near lossless too with a quoted insertion loss of 0.01 dB in the HF band to 0.55 dB at 18GHz. I normally run tests of the Mini-Circuit components when I receive them and find that the figures quoted are near spot on. I highly recommend these cables if you’re looking to upgrade your systems, and are available from the Mini-Circuits website, along with lots of other goodies that will tempt you.

Measurement of insertion loss of the Mini-Circuits ZF3RSC-542B-S+ Power Splitter/Combiner I also purchased as part of my plans for satellite communication monitoring. This is connected to the AirSpy SDR and takes feeds from two SatCom connections (currently deactivated) and a WinRadio AX-71C Discone Antenna. Mini-Circuits quote an insertion loss of around 19.5dB at 130 MHz which is confirmed here with a signal generated at -20dB being less than 1dB out at -40.48dB when passed through the combiner.

This image shows how the cables can be held in place without cable ties

The radio setup now includes two new SDR’s – an AirSpy HF+ and a standard AirSpy with the HF+ replacing the Enablia TitanPro. I’ve also reinstated my WinRadio G31DDC which had been in storage for a year or so. I really do like the TitanPro, and have put it into storage for the time being. The recording capabilities in particular are great with it being able to select 40 frequencies at once spread over numerous bandwidths, but I have had issues with the power supply – one being it caused interference. I attempted to make one of my own but it has a 6v(+/-1v)/2.5 Amp current requirement and no matter how many different methods of building my own supply using a 12v feed downgrading to 5, 6 or 7 volts, it just wouldn’t work in a stable manner. In the end it was easier to remove it and slot the G31DDC back in its place.

As it is, I’d forgotten how good the G31DDC is and I don’t really feel like I’m missing much thanks to the ability to use the other SDR’s with SDR Console V3 and it’s SDR Analyser.

The three 19″ racking units from Penn Elcom, along with all the shelves, have been very useful and certainly makes things easier when it comes to changing radios and connections over. I can just disconnect a few things and slide the whole unit out. I also obtained a 19″ Project box from them which I used as my main 12v switch unit. This is connected to two regulated desktop power supplies that act as master switches.

Although the SDR Console website page for the Analyser states it isn’t available yet, this is incorrect and it is downloaded with the latest version of the main programme.

If you’re a current user of V2 or have been in the past then you won’t notice much difference. You can have up to 24 parallel demodulators operating within the SDR’s bandwidth that you have chosen, all of which can run independent of each other in receive and record. You can also run each demodulator through a decoder such as MultiPSK independently and decode these in parallel with each other. This capability has taken that step towards those of the TitanPro, especially when being used with the Elad FDM-S2 that can provide a Maximum DDC bandwidth of 6144kHz’s.

Unfortunately, whilst you can schedule recordings of IQ data, you still can’t do this for individual channel recordings. This is a real shame as it would be a fantastic addition to the capabilities of SDR Console.

Getting back to the analyser though this does, in theory, cancel out the lack of channel recording scheduling.

When you record IQ data it is saved as WAV files, split into multiple ones depending on how long a recording you make . All of these files can be individually played back through the incorporated SDR Console player but even better is the use of the File Analyser.

With this you get a visual “image” of the complete recording, whereby after opening the analyser you get it to combine all the files into one XML file. For the image below I used the FDM-S2 with a selected bandwith of 768kHz centred on 4425kHz, hoping to catch calls to Russian Naval base Severomorsk in CW(RJD99) from ships operating in the region. I set the scheduler up to record from 0000z to 0700z which worked perfectly, giving me 78 files totalling 78GB – obviously, the bigger the bandwidth, the larger the total file size.

After clicking on New in the analyser and browsing to the relevant folder the WAV files are saved in, the analyser finds the first one and gives this as an option to open – it automatically adds the remaining WAV files and starts the process. This can take quite some time to extract, around 45 minutes for the example shown. But you only need to do this once because once it has finished you can save it as an XML file and open it at any time – in this case it was a 28MB XML file.

A note here – do not then delete the WAV files as the analyser still needs them.

As you can see, I was successful in locating calls to RJD99, and I have highlighted some of the others that I took a look at – this is just a screenshot of two hours out of the seven recorded.

All you then need to do is find any signal of interest, and after clicking on select and start in the top ribbon, click on the signal. This will then start playing the file from that location in the main SDR Console window. You don’t need to stay on that frequency, you can use the Console as if you were listening live and move around the frequency range you dictated in the bandwidth of the recording.

And, as it is basically a live screen you can do additional things such as record and use decoding software.

RJI92 calling RJD99 on 4416 kHz during playback of the Analyser

When using the Analyser I run this through a separate PC meaning SDR Console itself can carry on working on the main radio control PC. This is also handy if you’re away but have time to go through the IQ data using a laptop. Just copy over the original WAV files to a portable hard drive/memory stick and carry on as described above.

There are numerous other functions available for you to use with the main part of SDR Console, some I still haven’t had the chance to play with completely. I’m still exploring things such as the Signal History function which can store up to 48 hours of data. Here you can export data in CSV format to third-party programs such as QtiPlot. Signal history can also be used within the Analyser

This is useful as it can give you a quick overview into single frequency use, signal strengths, fading and such like. Definitely something I need to spend more time on.

It’s been a long time coming, but Version 3 of SDR Console has been well worth the wait. If you want to record and quickly analyse IQ data then I can’t think of anything else that does the job so well.

Coming up next…….

I’ve started using Harvester Signals Intelligence Software – Version 6 by SigintSystems and I’ll be running a series of blogs covering my progress with this excellent software as I learn how to use it to its full capabilities.

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A quick update & Roland Proesch Radio Monitoring books 2018

Firstly, a quick update on what’s been going on with me.

In the world of radios, ships, photos and Russians – not a lot!! No blog since September 2017 wasn’t what I had planned that’s for sure. Much of my writing time has gone to Jane’s, which has been great. This has meant I had to prioritise any free time available to them, having to put my blog on the back burner. Overall I’ve written or carried out analysis for around 10 Jane’s magazine articles since September 2017, as well as my continual fleet analysis on the Russian navy for Fighting Ships.

One of my articles from the November 2017 edition of Jane’s Intelligence Review

With regards to any radio monitoring, that also had to go on a back burner. When the shack was rebuilt as part of the house renovations I installed all the coaxial in temporary locations, drilled through the outer wall and coming into the shack through a large 50cm by 30cm hole in the interior plasterboard wall. This was in April 2015!! Hardly temporary!!

Due to the pretty crap weather we get here, and the fact that I needed at least 5 days of continuous good weather to be able to do all the connections outside, it has taken until the last week – 3 years later – to finally get the sunny days I needed at the same time as being off work.

Over the last year, the temporary connections had become worse and worse, with lots of noise causing interference. Nothing was earthed correctly either. Other factors such as the neighbours installing dreaded solar panels really screwed up everything, totally wiping out the main Russian navy day frequency they use for CW.

Not only that, with the hole in the interior wall being the size it is, it gets very cold in the room during the Winter – and the rest of the year for that matter – with a large draft blowing in most of the time.

Anyway, new outside connections are complete, in nice new waterproof boxes. Now the exterior part is done, I’m not weather dependant on the rest of it and hopefully I’ll be back up and running in the next month or so. I’ll do a full blog on the new setup once it’s complete.

Roland Proesch Radio Monitoring books 2018

For 2018, Roland Proesch has updated two of the five books he creates in his Technical handbook range.

The first is Signal Analysis for Radio Monitoring Edition 2018. This has nearly 60 new pages of information on how to analyse various waveforms, including a new section on Satellite signals – useful if you’ve already purchased his Technical handbook for satellite monitoring 2017. There’s also a section on describing how to analyse RADAR signals. Other things such as useful software tools and PC calibration is also included. Here’s a PDF of the contents with new information highlighted in yellow.

The other book is Frequency Handbook for Radio Monitoring Edition 2018. Whilst many people would say a book containing information on frequencies used by various utility stations, armed forces and other agencies is dated and old school, I tend to disagree. There is so much useless information out there online, I prefer using a book for looking things up that I may have found on the HF bands. Granted, a book does go out of date – normally as it’s being printed – but you can quite easily add your own entries in the right places if needed.

This update has several hundred changes of new, deleted and updated frequencies ranging from 0Hz to 30000kHz, and contains a section dedicated to ALE frequencies and idents.

Both books, along with the ones released last year in one of my previous blogs, are available from his website. As usual, he has his bundle offers which makes the books cheaper if you buy two or more at the same time.

I’ve used his books for years and highly recommend them.

Guide to the Royal Navy 2017/18

Published at the end of July 2017, the latest Guide to the Royal Navy 2017/2018 is the eight edition from the team at Warships International Fleet Review.

Contained within the 64 pages are photographs – some of which by yours truly – and data on ship classes and naval aviation. The data covers all aspects of the current UK naval forces, as well as future developments and also those of the past in a section on RN heritage.

As expected, the quality from the Warships IFR magazine is carried over into this guide and it is well worth purchasing at a price of £6.50 from either the Tandy Media website directly or from high street stockists such as W.H.Smiths (a full list of stockists is available on the Tandy website).

No doubt there will be those of you that think there won’t be much in the guide due to the ever decreasing size of the Royal Navy, but I hope that some of the screenshots below will show just how much detail there is contained within its pages.

An updated AIS system

Back in March I blogged about my AIS system, in particular about the LNA4ALL and how it coped with the low signal reception of my homemade antenna.

Things went really well until one day the reception dropped out completely.

A quick test of the system showed that something had gone wrong with one of the pieces of equipment though at the time I was unsure whether it was the antenna, the LNA or the NASA Engine AIS decoder.

As I was due to go away for a short while I decided to tell all the relevant websites that I feed (IHS AISLive, MarineTraffic and VesselFinder) that my system would be offline until further notice due to a technical fault, and that as soon as I’d worked out the issue that I’d get it fixed and back online.

The guys at MarineTraffic were very quick in getting in contact with me and offered to help with a new decoder as long as I didn’t mind being a beta tester for the equipment and some of their new software. I was very happy to agree to their offer.

The decoder they organised for me was a new Comar Systems SLR350ni Intelligent AIS Decoder and it arrived with me about ten days after I agreed to their offer.

The main thing that really appealed to me about this decoder was the fact that it links directly to your home network either by WiFi or hardwired using RJ45 Ethernet cable. This meant that I could install the decoder remotely, nearer to the antenna and out of my radio shack, but have full control of it from my main PC. The decoder itself is interfaced to a Raspberry Pi™ 3 computer, comes with aforementioned WiFi and Ethernet connectivity, 4 USB ports and an HDMI connector for a monitor display. It can be used in any AIS setup and is a dual channelled parallel receiver.

Installation was simple. Within 15 minutes the decoder was connected to my home-made antenna and we were receiving data – and at a much faster rate than the NASA due to the dual channel capability.

The MarineTraffic part of the agreement included some new software that they are testing, which includes the capability of sending received raw AIS data to five feeds such as AISLive. Any of these decoders obtained using MarineTraffic come with their host settings hardwired in so any data received through it is automatically sent to them – you don’t have to do anything to send data to MarineTraffic, just attach an antenna, connect it to your network and switch it on – that’s it.

In the new software there is a page where you can add other host iP addresses and port details. Doing this means a couple of things:

1 – You no longer need to use other software such as ShipPlotter or Neal Arundale’s NmeaRouter/AisDecoder software to forward on the data.
2 – You don’t actually need a PC connected directly to the Comar decoder.

The second point is interesting as it means you no longer need to have a PC running 24/7 to feed any of the AIS data to whichever sites you want. This is a bonus if you currently switch off your computers when you go on holiday or are away from home for a while. It still means you can provide the data whilst you are away.

Personally I have the following set up:
MarineTraffic (hardwired)
AISLive (iP host)
VesselFinder (iP host)
ShipPlotter (internal network address)
AIS Decoder (internal network address)

Using the ShipPlotter software still means I can get a better picture of what I am receiving, range of reception etc.; whilst using the AIS Decoder software means I can look at any of the messages sent in greater detail.

I have to say that I am very impressed so far, and highly recommend the Comar decoder. It is available from numerous online shops, but if you are going to feed MarineTraffic you may as well get it from their site, currently priced at €379.00. Doing this means it already comes pre-programmed to send to MarineTraffic.

A new antenna too

I had gotten round to testing all the equipment to see what the cause of the original loss of reception was and it turned out to be the LNA4ALL. This was a shame as I had new objectives for the LNA with regards to the reception of weather satellites so it means I’ll have to get a new one. Luckily I don’t need to replace the whole thing, just the circuit board, so it will be much cheaper – but a pain none the less, especially if I have the same issues with UK Customs that I had previously. The likely cause of the failure was an Electrostatic Discharge of some sort or other. There had been some Lightning storms nearby over the previous days and it could well have been this that had done it – strange though as my equipment is very well protected from this happening. The area I live in is prone to power surges and power cuts – the joys of living in a remote area in Scotland, still backwards in many things the rest of the UK take for granted.

With the loss of the LNA, this drastically reduced the range of my home-made antenna and so I decided it was time to buy a new one. I’d toyed with building a better one but in the end I just couldn’t be bothered and so I went for a Metz AIS antenna, bought from the Salty John website. Great service from them meant it arrived within 48 hours and so when it came to installing the Comar decoder I also rigged up the antenna in the loft space next to my home-made one at the same time.

If I have one complaint about the Metz, it’s that it doesn’t come with any form of protection for the co-ax connection area. This is especially strange as it is designed specifically for boats and would therefore be exposed to wet/salty conditions all the time. Add to that that the threaded area is over an inch long, much longer than what you would get with a UHF connector, this makes it a weak area for the lifetime of the antenna. If you were to install it outside (which is the general recommendation for AIS reception) then you would need to cover it in self-amalgamating tape and check it regularly to ensure it is still working. Not perfect if you need to climb up on the roof of your property.

One other option would be to use the tightening nuts supplied to fix some plastic or aluminium tubing around the connection, but again this is some extra hassle which could have been remedied by Metz themselves.

As it is, I seem to be getting great coverage from the Metz from it’s position in the loft, though I may still add a LNA4ALL to boost it even more.

With the antennas side by side I was able to run some quick comparisons between the two. The images below show the Spectrum analysis using my Rigol gear.

From the images you can see that with my messing around of the home-made antenna I had over trimmed it to be tuned to 180MHz rather than the required 162MHz. At 162MHz it measured in at 9.3dB which wasn’t even worth calculating the VSWR, whilst at 180MHz its VSWR was 1.23:1

In comparison the Metz antenna, which is a half-wave whip antenna, came in nicely at 83.6MHz with a measurement of 30.15dB/VSWR 1.07:1. Metz communications specify less than 1.2:1 VSWR so this is spot on.

With the new set up things have definitely improved. I also ran a quick test using AISDecoder to see how many messages the two antennas fed to the Comar, be it in a very basic manner of waiting till there was some ships being picked up, running the software with one antenna for a minute, noting how many messages were received and then swapping to the other antenna for the same length of time. In theory it is a reasonable test as the ships won’t have travelled far in that time, but not 100% perfect. Regardless, the Metz was able to pick up 19 messages in its minute test, whilst my home-made antenna only managed three! The test was carried out in less than five minutes.

In conclusion, whilst it has been a pain to lose the LNA4ALL, it has turned out better in the end for my AIS station. Statistically my data feed has improved no end for AISLive and MarineTraffic; and having gone away twice now since installation I have still been able to provide 24/7 coverage where I would normally have switched the whole system off.

Area coverage provided to MarineTraffic since the new installation. Fitting a LNA4ALL in the future should make this even better.

ShipPlotter example with the new installation. The bold plots are being received by my station and show 4673 messages received by 1032z. The image below shows the same but at 1753z and a message number of 28135. This averages out at about 52 messages a minute, though it was a busy time with lots of fishing boats in the area.

NOTES:

Following a couple of questions regarding the Comar decoder I’d like to add that it doesn’t have to be connected to the Internet or a Network to work. It can be used “locally” using the USB connections direct to a PC.

Also, you do not NEED to feed MarineTraffic if you don’t want to. If you don’t want to do this then buy a unit from another supplier which won’t have the files installed.

Fighting Ships 2017/2018

In the last month or so the latest edition of Jane’s Fighting Ships has been released. It’s available from the IHS online shop for the usual eye-watering price of £984.

One thing to note is that older editions of the yearbook are also available on the IHS website at much cheaper prices.

This is the last edition that Commodore Stephen Saunders RN will be the chief editor of, as he has decided to retire from the role after 17 years. Having been a contributor of JFS for the last five of those years it will be sad to see him go.

From now on there will be a multi-team of editors that will compile both the yearbook and the on-line version. I will be remaining a contributor, and will hopefully be getting more involved than I am already.

There could well be complications regarding contributing data and photographs and I suggest that if you do either of these then to contact the team at IHS as soon as possible. There is a strong likelihood that contracts will need to drawn up with regards to copyright usage of whatever you send in. The email address for the yearbook is JanesFightingShips@ihsmarkit.com

In the meantime, I wish Stephen all the best in his retirement – he’s done a great job editing the yearbook over the last 17 years.

Roland Proesch Radio Monitoring books 2017

Roland Proesch has announced that his latest books on Radio monitoring are now available at his website

Whilst Signal Analysis for Radio Monitoring remains a 2015 edition, the other three – Technical Handbook for Radio Monitoring HF, Technical Handbook for Radio Monitoring VHF/UHF and Frequency Handbook for Radio Monitoring HF – have all been updated to 2017.

There is also a new title – Technical Handbook for Satellite Monitoring – which is over 400 pages long and is aimed at those that are interested in satellite communication. The book is the usual high standard with figures and tables on satellite systems and the waveforms they use.

Because of the new title, all satellite information (nearly 100 pages) has been removed from the VHF/UHF book, but these have been replaced by new modes such as Radar, C4FM, DVB-T etc.

At the moment, there are no PDF examples available, but going to my previous blog at the last release can provide that information for now. I’ll update when they do become available.

I highly recommend these books and they are very well priced at 49Euros each plus postage. There’s also the usual bundle price discount if you want more than one – further information on the website.

But, if you don’t want to pay the postage and are heading to the HAM RADIO 2017 exhibition in Friedrichshafen, Germany on the 14 – 16th July, then Roland will have a stand there (A1-213). I’m sure he’ll be pleased to see you there – I wish I could attend, but I’ll probably have to wait the 5 years or so until I move to Bavaria myself.

The opening times and price list for tickets to the exhibition can be found here

Liman follow-up

Well, it’s a couple of days now since my blog on the Liman incident went live. I’ve had some great feed back on my coverage.

There has however been one individual that has not liked it so much. This is Steffan Watkins, owner of the blog Vessel of Interest. Mr Watkins was one of the unnamed characters I referred to in the Liman blog. He is widely regarded as a conspiracy theorist, and even has to go to the extent of denying it on his own blog. Whether he is or isn’t is irrelevant really.

Interestingly, a recent piece of work I was asked to do for Jane’s Intelligence Review magazine was to analyse an image of Russian navy Vishnya-class AGI Viktor Leonov to try and work out the various intelligence gathering systems that may be on board via all the different antennas visible. The actual article was written by Mr Watkins.

Now, up until this stage I really didn’t pay much attention to anything Mr Watkins wrote, mainly because what he wrote was aiming towards being the aforementioned conspiracy theories. But, he kind of came through with an interesting article – though it was nothing I didn’t know, as a group of us have been following Viktor Leonov for a few years now.

So, why hasn’t he enjoyed my blog? Well, I suggest you read it and see what he has come up with, and then come back here where I’ll answer his “questions”.

Hopefully, then you have read his blog on Liman now.

Firstly, lets talk about the “expert” part. He seems to think that I am condescending towards others from my comments. I am fully open to ideas and theories if there is evidence to back these ideas up and people also listen to what is being presented to them. In this case he did neither. And my references to things such as the Heather Sea evidence is clear – the ship wasn’t involved, it never was and yet people were still saying it was (not Mr Watkins I hasten to add, he hadn’t looked into anything outside the bubble of Liman). It was a quick and easy search through AIS history to see that it wasn’t, and yet people weren’t doing this. My reference to not being an expert is correct. I have no qualifications in the field of Radio Communications, I do not have an amateur radio licence and such like. I do not have a degree or a masters or any other diploma in the theories of radio – therefore I am not an expert. In ATC we have engineers that are experts in that – I wouldn’t dare tell them their job, just like they wouldn’t tell me how to keep aircraft apart. This is the reference I am making to being an expert.

He also mentions banter on twitter. There was no such thing, certainly not in my eyes. I’ve been around banter for decades – in the forces you need to be able to take it, and give it – and it is actually worse in the world of ATC. I can recognise banter when I see it. He also mentions an exchange of ideas. Yes there were exchanges of ideas, but he really wasn’t coming up with anything of substance. Instead, from his comments, he gave a picture that there was a conspiracy behind the incident – there had to be something because of the nature of the ship involved – an Intelligence Gatherer.

He actually says this in his blog:
Any ship could have an accident while at sea, in the fog, early in the morning. But, this wasn’t “any” ship; just by being a Russian Navy AGI (a “Spy Ship”) it makes me +1 suspicious. There is no good rational basis for that suspicion, except it’s a Russian Navy AGI, it definitely has sensitive gear aboard, and having it sink leaves a gap in whatever task it was doing, on the deployment it was on.

Why does this receive an extra degree of suspicion? Oh, that’s right, there’s no rational explanation, it’s just suspicious.

I wonder what Mr Watkins reactions were to the collision between a French Navy SSBN and a Royal Navy SSBN in the middle of the Atlantic in 2009. Holy shit, the French are at it again, trying to sink our navy 🙂

He refers to the fact that surely the Youzar Sif. H must have been able to have seen the Liman on radar:
The Liman was not a “stealth” ship, and as far as I understand, should have shown up on the navigational radar of the Youzarsif H; isn’t that why navigational radar exists?
Well, if two of the most expensive vessels in the sea, with some of the most sophisticated sonar and listening equipment ever made managed to thump into each other in the wide open Atlantic, then it is perfectly feasible for two ships to hit each other in thick fog in one of the busiest shipping lanes on the planet.

And it doesn’t even have to be in thick fog or underwater – ships hit each other. His Canadian navy had such an incident in 2013 in perfectly good weather when they were approaching each other.

Or there’s the Turkish Coast guard patrol boat that was hit in broad daylight, in the middle of the Bosporus, by a 158ft long Bulk carrier in August last year

Further about the radar he stated:
They were in thick fog, only navigating by instruments, and didn’t see a ship directly in front of them on radar?
Isn’t that weird?
I don’t think it reflects well on the Youzarsif H’s crew, unless the operations of the Liman were causing issues for the radar of the Youzarsif H. Yes, that’s wild speculation, because it makes no sense how a ship doesn’t notice a giant hulk of floating steel in front of it on radar. Make up your own crazy theory! It’s better than what we have now, which is nothing.

None of us know what radar system Youzar Sif. H has in place. I’ve been on quite a few ships in my time, civil and military – and of course I work with radar all the time. You get plenty of radar returns or “primaries” which you don’t know what they are, and you do your best to avoid them if you are not sure, but you have to make an assessment as what you think is a ship/aircraft and what is just weather (or a wind farm in a lot of ATC cases these days). The image here shows just a basic ships radar image, a modern one at that, so actually could be much better than the one on Youzar Sif. H – we won’t ever know I expect. Other radars are available of course, with more detail, but if Mr Watkins can work out what is what in this image then well done.

The next statement he produces is:
There have been no reports regarding who ran into who; or if it was a mutual effort. The news media is making it sound like they were both moving and collided in the fog. I’m not sure that’s correct.
He produces a list of things that could have happened – yes all obvious – but then doesn’t actual state why he thinks the news media are incorrect?? So why do you think this Mr Watkins?

He then mentions jamming of the AIS frequencies, but thankfully seems to have realised that this wasn’t the case. At the time of the “banter” he wasn’t stating that though:
See, there you go down the rabbit hole again. I’m wondering if the AGI screwed itself by engaging in EW in the same frequency range as AIS. 161.975/162.025 MHz range, within the usual Marine VHF band, right? Might explain the sketchy AIS coverage immediately prior.
Firstly, I’m still not sure what he’s referring to with EW. Early Warning?? Electronic Warfare?? Neither of which Liman is equipped for. And, secondly I went into great depths, the best I could at the time (see later) to try to explain the likely reason for the sketchy AIS coverage – all of which he kind of brushed aside for his more extreme likelihoods. Here, again he gives the air of being a conspiracy theorist.

We now get on to my favourite part of his blog:
•The Youzarsif H’s AIS signal was being received by terrestrial based AIS receivers, which Mr Roper described in his blog post with excruciating detail. The signal was very spotty before the collision, and crystal clear after the collision. This is the thing that really draws my eye and triggers my curiosity; it is the basis for much of my suspicion regarding this event. On the day Mr. Roper and I were discussing this he specifically dismissed my speculation that the issue could be related to the sender and insisted the gap in reception must be related to the receiver, or environmental conditions.
“This totally depends on the receiver not the sender! The receiver may have been off.”
-Tony Roper, 6:29 PM EST, May 4 2017
I tried to convey that my interest was less with the gap before the collision, and more with the immediate change to the signal quality (seemingly crystal clear reception) instantaneously after the collision, which Mr Roper had no explanation for at the time. It seems after reflection, he now theorizes the sender, may have had their antenna(s) facing away (blocked by the ship’s superstructure?) from the shore-based receiver when travelling Southbound (toward the Liman) and immediately after the collision turned around and faced their AIS antenna(s) toward the shore-based AIS-T receiver. This is fantastic speculation, and would explain how the signal went from terrible, to perfect, immediately, while other ships in the area had AIS-T signal all along.

Firstly, by excruciating detail I’m guessing Mr Watkins didn’t understand it. You must forgive me for trying to explain how something works instead of just giving less than half information on how something works. If he thinks my information was excruciating then maybe he should read the Propagation pages in the ARRL handbook which is spread over 30 pages. Or maybe he should go to websites such as:
Make more miles on VHF
HF Propagation tools
Or one of the many pages by Tomas Hood on propagation
It is obviously a fault of mine to make something interesting for the reader, that will hopefully teach them something.

I said above that at the time I did my best to try to explain to Mr Watkins what may have happened. This he seems to have thrown back in my face, alluding that I may have changed my mind on my original thoughts. I didn’t dismiss his thoughts but pointed out that there may have been a break in coverage. The interesting thing is the quote he has used, taken at 6:29PM EST. This was actually 23:59PM UK time, I was in a hotel room, 450 miles away from my computers and AIS systems. Maybe Mr Watkins has presumed that the rest of the planet is running at the same time as Canada, and that we were all glued to our PC’s? I made the best assessment at the time – and you know what, I wasn’t far wrong in the theory of coverage, as I proved in the blog.

He says I have “reflected” and changed my mind. No, I haven’t Mr Watkins. It’s a combination of both sender and receiver. I didn’t reflect. What I did was, on getting home, do some further analysis. Something Mr Watkins has quite clearly not done. He can only produce the same data on the what Youzar Sif. H did both before and after the incident. He still hasn’t come up with anything else – yet he has the nerve to criticise my analysis.

Come on Mr Watkins, show us some workings out. Do some actual analysis.

Here’s something for you. Data taken today from the same region.

The image below shows the tracks for various ships and their plots as received on AISLive

Holy crap – how do we explain all those gaps in the plots especially the ones on the rough route Youzar Sif. H took?? How the hell does the furthest ship away from any receivers have the best plot history?? Hmmmm, please do tell Mr Watkins. Maybe the Russians are jamming the area from outer space? Maybe there’s another AGI there?? Or maybe there’s just a poor area of reception.

The picture below shows the same area, at the very same time, but this time taken from MarineTraffic.

I’ve purposefully highlighted Reina as it is also highlighted in the AISLive image. The red ship to at the bottom is also on the AISLive image as the fully tracked ship. But what is that? MSC Eleonora is showing here, but isn’t on AISLive – what the hell?? How does that happen?? Please explain with all your worldly knowledge Mr Watkins.

Here’s some extra data for you, just so that you realise that AIS receivers aren’t on all the time (mine was off whilst 450 miles away for the weekend by the way). The three receiver examples that I used for the blog have the following averages for receiver availability over the last two months:
Istanbul = 93.3%
Burgas = 98.9%
Elena = 97.95%
So, not available all the time then.

He ends the large waffle with:
Can we prove this theory with the available data? Well, it’s certainly not as clear as I would like it to be. It is still crystal clear that immediately after the collision the AIS transmissions went from random times between successful transmissions to a steady stream at 3-4 minutes

The following day, still in the hotel 450 miles away from all my gear, I sent Mr Watkins roughly the same as the above showing a plot of another ship with the same loss of coverage. That obviously wasn’t enough evidence to make it “crystal clear”. I then produced my blog with further evidence – including an example of Youzar Sif. H with a loss of 14 hours of coverage – which again obviously wasn’t “crystal clear”, but was in fact excruciatingly full of too much detail for Mr Watkins. I have now produced the above which explains – yet again – that there are gaps in the coverage, yet other ships somehow have a better plot history. I suspect though, that all this will be far too foggy for Mr Watkins and he still will not be able to see anything clearly – except for a conspiracy.