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.

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Quick LNA4ALL test

Despite the best efforts of the Royal Mail service, I have been able to get my hands on a Low Noise Amplifier created by Adam at LNA4ALL. The Royal Mail showed just how useless it is, when the parcel arrived here in the UK in just 11 hours from Croatia on February the 14th, but then not getting delivered to me until March the 14th – yes, one month! There is no surprise that courier companies such as DPD and Hermes are getting more business than the Royal Mail – they are bloody useless.

Anyway, the reason for the purchase is for a later review on an AIS dongle that I will be testing, but which has unfortunately been possibly damaged before getting to me.

So, as I had some time to spare I thought I’d run a quick test on how the LNA performs against the claims that is shown on the LNA4ALL website. For the test I used a quickly built 12v to 5v PSU that was connected to a Maplin bench PSU and also a Rigol DP711 Linear DC PSU where I could ensure a precise power input. As it was, it was good that I used the DP711 because my quick PSU was only chucking out 1.2v at connection to the LNA4ALL, despite an unconnected output of 5v – some work needed there I think.

Despite this lower power the LNA4ALL still worked with just the 1.2v input, though the results where not as good.

Other equipment used were a Rigol DSG815 Signal Generator and a Rigol DSA1030 Spectrum Analyser (no longer available), along with various Mini-Circuits shielded test cables. The Rigol equipment I purchased from Telonic Instruments Ltd last year.

Below then is a table that contains all the relevant data. As you’ll see the Gain claim is pretty much spot on with some being over. Just a couple of frequencies are below that which is claimed, especially at 28 MHz.

LNA4ALL Frequency data

A couple of things to note.

Firstly, somehow I managed to miss testing 1296 MHz. I obviously didn’t put it in the table in Excel before I started 🙂 Also, the DSG815 only goes up to 1.5 GHz so I couldn’t test above that.

Secondly I ran a test for the AIS centre frequency of 162 MHz, for which there was no comparison to the LNA4ALL data. A gain of over 24dB though shows that the LNA would be perfect for those of you with AIS receivers that may want to get better reception. To prove the theory I compared the LNA reception against data without it connected to the NASA Engine AIS receiver that I currently use. In ShipPlotter I average a max range of around 15nm without the LNA, but with it connected this increased to around 22nm. The number of messages received also tripled as it was able to dig out the weaker signals.

The NASA Engine isn’t a bad receiver, but it is a frequency hopper rather than a dual monitor, and so it changes between the two AIS frequencies every 30 seconds (161.975 MHz and 162.025 MHz). I suspect a dual monitor would give better message numbers and range.

Below is a graph made using the excellent software by Neal Arundale – NMEA AIS Router. As you can see the message numbers (or sentences) for over an hour are pretty good – well, it is a vast improvement on what I used to get with my current “temporary” set-up, with 419 messages received in an hour. The software is available at his website, for free, along with various other programs that you can use with AIS. If you’d rather not use ShipPlotter he has created his own AIS Decoder which can be linked into Google Earth and such like. Visit his website for more information.

My antenna isn’t exactly top-notch. It is at a height of just 4 metres AGL in the extension loft, and it is made from galvanised steel angle bead used by plasterers to strengthen corners prior to skimming – this I cut down as a dipole for a target of 162 MHz. As usual with my trimming of antennas, I cut just too much off and ended up with it cut to 161.167 MHz. It gives a VSWR of 1.018 and Return loss of 40.82dB, with 162 MHz being approx. 30dB Return loss which equates to 1.075 VSWR – that will do.

Also, as I live right on the coast, about 50 metres from the sea, I’m practically at sea level, which doesn’t help much with range and signal reception either. Despite this the antenna produces great results, though it is just temporary until I can get a new homebuild up on the roof.

VSWR reading for the homebrew loft AIS Antenna

The LNA4ALL retails at various prices depending on what option you go for. I went for the aluminium box version so it was around £54 including the delivery. I had looked at a Mini-circuits equivalent, and when it looked like the LNA4ALL was lost I did actually order one. But this was nearly twice the price, and seeing as the LNA4ALL contains many components from Mini-Circuit I doubt it is any different really.

All in all the LNA4ALL is all you need to boost your weak signals – couldn’t get any more all’s in 🙂

February’s Blackjacks

After a couple of days of teasing us with the standard “W” markers in CW, on the 17th February the Russian Air Force (Военно-воздушные cилы России [BBC России]) carried out a Long Range Aviation mission using two Tu-160 Blackjacks.

I was able to monitor nearly the whole mission on HF (both in CW and Voice USB), with a small amount on UHF (though no Russian Air to Air voice comms were received on VHF/UHF) and following some investigation into my data along with other logs and reports from the internet and friends, I can now compile a rough idea of the routing they took on their journey to the English Channel and back again.

The first reception I had that showed a mission was taking place was at around 0830z when a standard 3 figure group message was sent by IWV4 but unfortunately I was just setting up my gear and so missed it to write down. Further “W” markers took place at the usual every 20 minute schedule of 0840z and 0900z, with IWV4 sending another message at 0903z to the aircraft. This call gave us the CW callsign for the aircraft, probably the IL-78 Midas4YMA

Russian Air Force TU-160 Blackjack RF-94104 “Alexander Golovanov” © Crown copyright 2016

As is standard, the early part of the mission was relatively quiet on CW with markers only, though there was one unusual thing that took place around 0920z. Firstly there was no 0920z “W” (this only happened one other time for the whole day at 1600z – the 20 mins schedule was kept going solidly otherwise) and secondly, at 0922z, there was a sending of data on the frequency. The first eight minutes was a carrier tone centred exactly on 8112; with the full data commencing at 0930z continuing until 0943z. Unfortunately, the CW recording I had for the day got corrupted so I wasn’t able to analyse the signal to at least try and determine what type it may have been. Of course, it could have been coincidence as we all know that many of the frequencies used by the Russians are shared, but this does seem almost too good a coincidence. One thing is noteworthy in recent missions, and that is the big reduction in CW messages over the large increase of voice messages – are the Russians trying out a new data messaging system for their Long Range Aviation fleet?

8112 continued in the usual manner for most of the morning, with the occasional message or “radio check” [QSA] but there wasn’t much else. The Winter CW frequency for the aircraft side of the “Bear Net” had always alluded us and was in fact the only missing frequency we had for the whole net, so it was just the ground side of the duplex network that I was receiving. I had 8990 down as a back-up frequency for their voice comms and I was monitoring this frequency on my Icom IC-R8500 in USB mode, with all the remaining Winter frequencies on the Titan SDR Pro. I was also using the Titan to monitor most of the Oceanic frequencies in case they were coming this way, something useful to do as this can sometimes give away the rough position of the Russians. Because of this set-up I had the SDR monitoring the Oceanic frequencies in the 8MHz range. The bandwidth I’d allocated also incorporated 8990 and it was during a QSA check at 1205z from IWV4 on 8112 that I noticed a faint trace of CW on the frequency! I quickly changed the mode on the Icom to CW and caught the end – “QSA3” – nothing else followed, but it looked like I had found the Winter CW airborne frequency for the “Bear Net”. But, I had to be sure.

Russian Air Force TU-160 Blackjack RF-94101 “Paval Taran” © Crown copyright 2016

Up until now there had been zero voice comms on 8131, the primary Winter voice frequency, but not too long after the 1205z QSA check on CW the first call came with 44732 calling KATOLIK followed by a call to BALANS after not much luck with KATOLIK. There was one more call after this on 8112 before this frequency went to markers only, but there was a reply on 8990 confirming that this was the Winter CW frequency for the aircraft. The complete 8112/8990 transcript can be found in PDF format in my full CW log

Going from various reports, the Northern QRA had not launched so this led me to believe that the Russian aircraft were not coming in the direction of the UK, but when I noticed on my SBS that the Tanker was travelling north from Brize Norton, then I wondered if they were. The only comms I had was from the Tanker with Swanwick Mil so I presume (and with no logs showing anything from Lossiemouth) that a long range track of the Blackjacks was taking place.

Certainly, on Oceanic warnings were being passed about the “unknown” traffic heading south and it’s from this information that I’ve been able to roughly guess their initial routing, down through the Shetland Island and Faeroe Island gap to near ERAKA, before tracking south along the 10W line – like I say, a rough guess, but going on previous routes this won’t be far out. They probably got to around the NIBOG area before tracking SW to go around Ireland, before heading in again towards Lands End and the English Channel.

Voice comms on HF with BALANS was pretty continuous by this stage, with three potential callsigns heard. Two would have been the Blackjacks, 44731 and 44732, with a third more than likely the support IL-78 Midas tanker that remained clear up to the north and so was much weaker with me – I think it was 60991 but was too weak to tell, with only the readback from BALANS copied.

At about 1505z it was reported that two Typhoons from Coningsby that had launched about an hour before, and had been holding in ARA10W, had joined up with the “unknowns” and these were identified as Tu-160 Blackjacks. The comms were again picked up by Kyle, and the Typhoons gave full details including the tailcodes, with the lead aircraft being RF-94101, the second RF-94104. The Russians name their Tu-160’s and these are given “Paval Taran” and “Alexander Golovanov” respectively.

By coincidence, at 1510z, 44732 calls BALANS with a message starting 502. I always suspect that they send messages out when they’re intercepted and I expect this was one of those messages. It could well have been that they were entering the Channel though, it’s hard to tell, but certainly for the whole time they were in that area, the messages sent began with 502. Around 1600z the French QRA also joined up and from images produced by the MOD, these were shown to be a single Rafale and a single Mirage 2000C – callsigns noted on Fighter Control as MASTIFF01 and MARAUD03.

Russian Air Force TU-160 Blackjack RF-94104 with a French Air Force Rafale and Mirage 2000C © Crown copyright 2016

From there the Blackjacks turned around and I expect pretty much followed the same route back. I could certainly tell that they were near to me later on, they were ridiculously loud on HF.

Below then is a copy of my voice logs, along with the recordings I made. A good test of my recently installed Wellbrook Loop that I’d finally been able to put up on the mast just the week before, after having it for nearly three months! Scottish weather!!

NOTE – These recordings are copyrighted to me. It has been noted that other recordings have ended up on YouTube, uploaded by a third party. Should this happen with my recordings, further action will be taken

8131

1216z 44732 calls KATOLIK

1217z 44732 calls KATOLIK [KATOLIK very faint]

1218z 44732 calls KATOLIK, BALANS replies

1220z BALANS passes message 130 525

1222z BALANS calls 44731 numerous times
– Note, contains all of the above

1226z 44732 answers, BALANS passes message 130 525

1232z 44732 calls BALANS with message [too faint to copy]

[messages continue until 1245z, all too faint, multiple callsigns]

1302z 44732 calls BALANS with message 157 133 796 290 525 853

1306z BALANS and 60991[?] 532 598 757 706 057 162 363 395

1318z BALANS passes message 727 to 44732

1356z 44732 calls BALANS with message 197 077 950 525 305

1510z 44732 calls BALANS with message 502 549 447 360 981 848 842 366 215 492 481

1551z 44732 calls BALANS with message 502 956 447 339 822 532 842 942 563 592 339

1612z 44732 calls BALANS with message 502 411 447 132 196 010 565 564 978

1641z 44732 calls BALANS with message 926 429 564 695 525 447

1745z 44731 called by BALANS

1750z BALANS calls 44731 with message 861 408 850

1826z 44732 calls BALANS with message 976 170 408 953 525 055

160217map

Approximate routing of the Tu-160 Blackjacks

One final thing to note – on exactly the same day in 2015 (day of the year, not actual date, so the third Wednesday in February) the Russians carried out almost the same flight, going down the West coast of Ireland. Further information on that mission, including HF recordings, can be found in Bear Hunting – part two

Bet you a few quid they’ll be back same day next year 😉

TitanSDR Pro demonstration

After receiving quite a few requests on information about the Enablia TitanSDR and it’s capabilities, I decided it would be good a good idea to create a demonstration video that would hopefully show just how good an SDR it is. The video is at the end of this blog.

I think that a lot of people can’t understand just why the two versions are the price they are, especially when it seems that a new dongle SDR is being evolved every day at a ridiculously cheap price. Yes, they are expensive but when you compare the price of these SDR’s to a top end desktop receiver, such as the Icom IC-R8500 for example, then it is fairly comparable.

But you must consider the fact that the Titan is really more than one receiver. The Pro version is 40 receivers, the standard is eight. You can’t record independently using the Icom, you need some additional software or a digital voice recorder plugged in to the receiver; and even then you can only record the one frequency – the Pro can record 40 frequencies, the standard can record eight.

The TitanSDR Pro can monitor up to 40 frequencies at the same time. Here, 10 frequencies are being monitored, mainly Oceanic ones.

The TitanSDR Pro can monitor up to 40 frequencies at the same time. Here, 10 frequencies are being monitored, mainly Oceanic ones.

Then, you can’t really record any bandwidth to play back using the Icom, but both versions of the Titan can record up to three separate bandwidths. These can then be played back, either through the SDR itself, or on another PC using the supplied USB dongle that carries a second version of the software – and if you did this you could be listening to, or recording, further frequencies or bandwidths. And all these separate bandwidth recordings can, of course, be played back multiple times, with multiple recordings being made within them; or data can be decoded; or signals analysed – what ever you require from an SDR.

This image shows the Titan monitoring 12 frequencies, 6 of which are decoding ALE using PC-ALE. This can take place in the background, while listening to the other frequencies on the SDR.

This image shows the Titan monitoring 12 frequencies, 6 of which are decoding ALE using PC-ALE. This can take place in the background, while listening to the other frequencies on the SDR.

But, of course, this is just standard for any SDR isn’t it?? But is it?? Can you think of another SDR that has the capability to monitor/record 40 frequencies at once? I can’t.

The nearest SDR I found to the Titan in quality of not only recording capabilities but in quality of filters etc. meant that I would need to buy around 13 SDR’s of this model and spend over €30,000. Yet, just one of this model costs pretty much the same price as the Titan. Now, with that knowledge, the price of the TitanSDR’s really doesn’t seem that bad after all.

Don’t forget, the TitanSDR is a Military spec. SDR, designed originally for agencies to monitor multiple frequencies for analysis and data collecting. It already has top specifications but Enablia are still willing to listen to the users and add requested features if they can. They have already done this with quite a few ideas that myself and other users have suggested.

You'd think that the Titan would be a CPU guzzler wouldn't you? Well it isn't. Here the SDR is running 31 frequencies, multiple decodings using MultiPSK, and PC-ALE. The CPU is running at only 27%, and that was it's max reading.

You’d think that the Titan would be a CPU guzzler wouldn’t you? Well it isn’t. Here the SDR is running 31 frequencies, whilst making multiple decodings using MultiPSK and PC-ALE. The CPU is running at only 27%, and that was it’s max reading.

 

NAVTEX

Canon 5D update

Before going any further, just a quick update on the repair to my 5D that I carried out in my last blog

Unfortunately, it only lasted about another 200 shots before the mirror became unstuck. So I decided to purchase a new 5D mk III, but before I did I looked in to how much it would cost to get the current one repaired to either then consider selling on or to give to my girlfriend who is just starting out in photography. I decide to search locally, choosing Glasgow as the nearest biggest place to start. Straight away I found a company called A.J. Johnstone & Co. so I gave them a ring to find out the bad news. AJJ

Well, it turns out, all that information I’d previously reported about the cost of repairs was total rubbish. As it’s a known Canon fault the repair is free!! The only cost was for the postage. Well, this was great, no new camera needed. I sent it off the next day by courier adding a note asking to give the sensor a clean; and one of their team rang me the day after that to confirm I’d pay the £38 for the sensor clean plus £10 postage.

Not only did they do the repair and sensor clean, they also replaced the focus screen, updated the firmware and gave the camera a good clean externally. I highly recommend using them if you need to service your camera. The sensor cleaning service is same day with no prior booking required if you’re able to go to their premises. I was without my camera for about 6 days in total, including the postage days.

Their website can be accessed by clicking on the image above.

NAVTEX

With the recent Joint Warrior exercise having taken place here in the UK I thought I’d mention the NAVTEX decoder I use for getting information on where some of the action may be taking place. Why use NAVTEX? Well the Royal Navy, in conjunction with the Queens Harbour Master (Clyde), produce a twice daily warning on Submarine activity off the west coast of Scotland. This is due to a fatal incident in 1990 involving a fishing boat trawler and a dived submarine which unfortunately got snagged up in the trailing net. SUBFACTS, as it is called, is broadcast twice daily on the NAVTEX frequency of 518kHz at 0620 and 1820 UTC and it gives the approximate location of any submarines that are operating within the next 24 hour period. Also included in the broadcast is information on any live firing that is taking place in the danger areas on the coasts and at sea off western Scotland – this is known as GUNFACTS. Further information can be found here

Anyway, back to the software I’ve been using recently. This is the Frisnit NAVTEX Decoder created by Mark Longstaff-Tyrrell and it’s totally free. Not only does it decode NAVTEX messages, if you register the decoder (still free) it means you can upload your receptions to the frisnit server giving them access to anyone. The main aim of this is to provide people at sea with the ability to check NAVTEX messages without the need of having an actual decoder on board. As long as you have access to the internet you can access any uploaded messages. And you don’t need to upload messages yourself either, the messages are freely available to anyone, even if you don’t have the software yourself.

A SUBFACTS message as decoded with frisnit NAVTEX

A SUBFACTS message as decoded with frisnit NAVTEX

As you can see from the image above, as well as a raw data view, there’s also a messages view. All the completed messages are stored on your hard-drive giving you the ability to go back through all the messages you have received.

As well as using NAVTEX for getting the submarine information, it’s also a very useful tool for getting accurate weather forecasts, especially if you live right on the coast as I do, and doubly especially if there’s storms brewing out over the Atlantic.

There’s other features available on the frisnit website, so if you’re interested in NAVTEX take a look, and even try the software. I don’t think you’ll be disappointed.

The Spectrum Monitor article

tsmcoverI’ve recently had another article published in The Spectrum Monitor. The subject of the article is monitoring the Russian Air Force Strategic Bomber networks on CW and USB. It was good fun to write, but also quite complicated as it’s one of those subjects that can be hard to explain. Anyway, I think it has been received well.

The “magazine” is available as a single edition for $3 or why not subscribe for a year for $24 – that’s $2 a month for around 100 pages of great articles. There isn’t another Radio magazine that can offer such great value, especially here in the UK.

Antennas

With everything else that’s been going on, I totally forgot to do a blog on my new antenna set-up; and when I say new it’s now nearly 12 months old

My old set-up wasn’t too bad with a longwire stretching from the study and just tacked on to the top of the fence and wall around the garden, then from an old washing-line pole to the corner of my garage at the far end. This created a horizontal L shape with a slight incline. Reception was very good although as the antenna wasn’t earthed there was a bit of noise. Luckily I live fairly remote so there isn’t the usual interference from neighbours TV sets etc, but I wanted to improve the signal by creating a better set-up.

As a back up, I also had a Garex Compact Active antenna in the loft which I also wanted to move outside. This is a great active antenna, designed initially to be used on small boats and was perfect as I live on a harbour and have to cope with the same atmosphere and conditions that would be found at sea. Corrosion of metal is a big problem due to the conditions around here, and this was evident in the longwire.

With this in mind, I selected Military Spec. Kevlar Antenna Wire from Nevada Radio. Not only is this wire weather proof and light, it is green and will blend nicely into the background around here, just like camoflage (another reason why it’s used by the Military). It is also incredibly strong, and once tensioned will not stretch like standard wire

Mil. Spec. Kevlar Antenna Wire

I also ordered a few other things including 100m of Military specification RG58C/U coax cable, some Ceramic Insulators, plugs and sockets. Nevada have never let me down and I can recommend them totally

Prior to all this, in a general conversation with John who supplies me with my firewood I mentioned how it would be great to have an old telephone pole to use as the main mast for my antennas – “well, I have loads of them” he says. So when it was time to get it all together in the New Year, John delivered the pole, all 8 meters of it!

Telephone pole after delivery

Telephone pole after delivery

The design was simple really. It would be the longwire stretching from the house in an L, with the down side running down the wall, connecting to the Co-ax, which would then run into the house via an air brick. Grounding would run from the co-ax connection to a copper rod driven into the garden. There would be a splitter in the loft space which would then feed both my Icom IC-R8500 and SDR-IQ radios.

The Garex would be placed at the top of the pole and the co-ax would then run along the wall and fence to the house; and in through the same air brick. The co-ax would continue through to the Icom as my second antenna

With rough calculations I realised that with a pole of 8 metres in length, I was going to need a pretty deep hole to put it in. BT use a screw type thing to dig the hole to the correct depth for their installations, but I didn’t have that, just a spade. 8 metres was too much anyway so I decided to cut off about a metre and calculated that around a 3 foot deep hole would be ok, with 6 bags of quick drying cement to firmly secure it in.

Garex attached to the pole

First of all though, I needed to attach the Garex to the top of the pole as I didn’t fancy doing that once it was upright and in the ground. Far easier to connect it all up and then plant the post into the hole. There are the usual steps attached to the pole which would be ok to use for general maintenance but it was going to be hard work getting the screw bolts into the solid wood of the pole that were needed to secure the mast mount.

Longwire clamp and step

With the Garex mounted and the cable run complete, it was then time to turn to the longwire. Again, it was going to be much easier to attach first and then raise the pole into position. BT had left the wire clamp on the pole so after a bit of a fight to get the bolts out that connected this, I was able to service them by wire brushing off the rust and corrosion before reconnecting them with some copper grease added to stop any further rust. To help secure the wire a bit better I first threaded some garden wire through some yellow/green earth sleeving which was then fed into the clamp and I then put the wire through one end an insulator. Then I fed the longwire through the other end of the insulator and tied off the wire using a standard camping guyrope tensioner, as unlike conventional wires that you wrap around itself the Kevlar wire uncoils due to its great flexibility. The tensioner butts up against the the insulator stopping the wire from going through the hole

So with both antennas attached and the hole dug, it was time to get the pole up. This turned out to be very easy, and with some assistance to hold it steady and totally vertical, I poured in the 6 bags of quick drying cement. After about 10 minutes it was ok to leave the pole on its own, and I waited a further two days before stretching the longwire across to the house

Whilst I waited those two days, I carried out the remaining tasks of getting all the co-ax in place and fully connecting the Garex to the Icom. Already, with the Garex, I could tell the difference that the new location made. The noise floor was much better, and there was no interference at all from anything electrical. The co-ax and splitter were all connected and the run down to the study was also completed, although I had previously needed to rearrange my whole desk to get everything in a better position in anticipation of this project

Shack

Shack

Prior to the desk change I needed to stretch quite a way to the Icom, normally needing to stand up, but now I can just adjust from my seat as it is within half an arms length. I had also connected up an old NAD amplifier and two NAD speakers to the SDR-IQ via the second soundcard in my PC

When it came to the final connection of the longwire to the co-ax, I just used a standard chocbloc, placed inside a waterproof electical box available from most DIY stores. Getting the wire nice and tight wasn’t a problem using an insulator at the corner and end of the L, and I left a little slack to feed into the waterproof box. The earth rod was connected by some old wire to the outer shield of the co-ax and we were good to go

RG58 running into the house via an air brick. Even in this picture it's hard to see the Kevlar wire

RGU58 running into the house via an air brick. Even in this picture it’s hard to see the Kevlar wire

The results were excellent. Nice clear signals with hardly any outside interference. I get the occasional trouble with electricals, normally my own PCs, but in the modern world this is hardly surprising (or avoidable). The longwire runs almost exactly North-South, which is perfect for what I normally listen too – Russian Navy and Military transmissions, but it’s also perfect for getting the Ocean traffic and USA

Overall, I’m very pleased with it. With the use of an old telephone pole and green wire, the whole antenna has basically disappeared into the background. After some chats with neighbours most hadn’t even noticed it had gone up. In fact, one even said they thought it had been there for years

Finished longwire running down to the house

Finished longwire running down to the house

Looking back to the pole

Looking back to the pole

Another angle on a sunny day

Another angle on a sunny day