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 🙂

Mini-Circuits and Stamps

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I recently received a global email from Mini-Circuits CEO, Harvey Kaylie, informing me of a Holiday Season discount. A copy of the email is below:

To our valued friends and customers,

To say thank you for making 2016 a successful year, we’re pleased to announce a special Holiday Season Discount:
All purchases of any quantity of Mini-Circuits catalog models ordered and shipped from our webstore on minicircuits.com from December 1st through December 31st will receive a 10% discount!

The discount will appear for items in your shopping cart on our webstore checkout page at the time of purchase. Please see our website for terms and conditions. This offer expires on December 31st, so don’t miss out!

From all the members of the Mini-Circuits family to all of you, our customers, we wish you a very happy, healthy holiday season!
Warm regards,

Harvey Kaylie
Founder and CEO
Mini-Circuits

I have checked with the UK supplier and I can confirm that the discount is available outside of the USA. Just order what you want as normal through the Mini-Circuits website.

Mini-Circuits components

Some of the components I have bought from Mini-Circuits this year

I bought some leads and components a few months ago and have been impressed with the quality of each item. The service from the UK supplier was excellent, especially as I had to change the order part way through the processing. All the components came from the USA, but the delay was minimal.

If you need some new components then get in there quick for the 10% discount.

 

Stamps of Radio Stations by Continents and Countries

At the end of November the SWLing blog had a post about collecting postage stamps with a connection to radio.

I’m by no means a proper stamp collector but the reason I found the blog of interest was because in August I had actually bought some First Day Covers and a Mint set of stamps commemorating 50 years of the BBC on Ascension Island. I had been stationed on Ascension in the 90’s whilst in the RAF and I spent quite a lot of my days off at English Bay beach which is right next to the transmitter site. Plenty of good memories.

The SWLing blog was about a Word document created by Lennart Weirell of Sweden. He has been able to collate a list of all the stamps that has a connection with Broadcast Radio and turn it into a twenty-four page document. It lists the 125 countries that have produced such stamps and the information includes date of issue, the Michael number, value (at issue) and name of the stamp. There are also tick boxes so that you can mark off whether you have these stamps in your collection. stamps

It doesn’t say this in the document but you can however go one step further than the tick boxes. If you have a scanner, just scan your stamps into a picture folder and then create a link to each relevant picture in the Word document. It’s as simple as highlighting the stamp name for example and then clicking on the Hyperlink button in the Insert tab group of Word (you can also use the Control-K shortcut). Just find the picture folder and the scanned image and link them up. As long as you don’t change the image location, each time you go to the Word document, clicking on the link will open it up.

The Word document is €4, but contact Lennart by email first so that he can send you a PayPal invoice. His email address and further information about the document is available on the image above.

The 50 years of the BBC stamps are available from the Ascension Island Post Office website.

First day cover

A scan of my First Day Cover “50 years of the BBC on Ascension Island” stamps

The Spectrum Monitor articles and the MilCom Forum

I’m pleased to say that I’ve had two articles published in the July edition of e-Mag The Spectrum Monitor

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The first article is about the Joint Warrior exercise that took place in March/April this year, and how and what to listen out for when these exercises take place twice a year in the UK. I wasn’t expecting this article to be published until September so this was an added bonus this month

The second article is about how I got into listening to Air Traffic Control and how this then took me down the road to becoming an Air Traffic Controller, an aviation/military photographer and writer, and into monitoring the radios in general – in particular HF

As well as the articles, there’s about 11 photos of mine included alongside. I also provided the cover image.tsmcover

The magazine is available either to buy individually at $3 each or by subscription for $24 for one year. Either way the magazine is well worth the money

MilCom Forum

About a month ago now, a new forum was created for the Military Monitoring enthusiast – MilCom

The main aim of the forum is bring together those of us that are interested in monitoring Military Communications, be it VHF/UHF, HF, CW, data, SATCOM etc. The posting of radio logs is actively encouraged. In just a month the membership has passed 110 with posts already at 850+; and this is without any real advertising of the forum. One thing you’ll notice if you head over, is that it isn’t just about Aviation. The forum covers all areas of Military Communications – Aviation, Maritime and Land (Space too if you really want to)

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As well as the forum area there is a database section which contains information on Military Callsigns, VHF/UHF frequencies, HF frequencies and other things such as common abbreviations and terms used by the Military. There’s also an interactive map. These databases are updated almost daily by a team of us, and can also have anything missing submitted to the team for addition once confirmed. The databases are continually growing, are more accurate than any printed publication (which is generally out of date the day of printing) and more importantly – FREE

The only proviso to this data being available is that members participate in the forum and do not just “lurk”. The membership is continually monitored by the team and trimmed if necessary. That being said, we are a friendly group so don’t let the rules put you off – instead join up and participate.

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