Radio Rusty Bolt?

Not had too much time over the last week or so to do much radio wise, but the other day while scanning around in the vhf low band found an odd signal on one of my scanners at 70.860MHz. This is the part of the spectrum that was used by the fire brigade until the introduction of the airwave system. Strangely it was a WFM signal and after a few minutes of music identified itself as BBC Radio Nottinghamshire!

Where I live isn’t brilliant for radio reception, but the BBC station is one of the stronger due to a nearby local ‘fill-in’ transmitter so I suspected it was breakthrough or some product of intermodulation. However I wasn’t sure if it wasn’t some ‘cordless headphones’ or other form of AV link or baby alarm given the proliferation of Chinese cheap and cheerful FM modules available that can operate at this frequency. That now seems very unlikely as the signal has been present continuously for days now.

To try to rule out any internally generated image I tried some of my other scanners, with different antennas and found the signal on them too. However one of them did exhibit some pager breakthrough as can be seen in the following video.

It therefore does suggest to it being an intermodulation product, but exactly what is causing it I am unsure. We have cast iron guttering on the house which has been recently repainted, so could this be caused by a rusty bolt that has been disturbed now acting as a diode?

Very curious…

Weekend update

Well it was busy weekend and managed to achieve some of what I hoped to.

On Saturday morning I had a trip up to Lincoln to visit the Lincoln Short Wave Club I have for some time been considering taking the plunge to get an Amateur Radio Licence and I’d inquired about any foundation courses and exams they were holding. The secretary contacted me as there is the chance of course in the near future so I popped along to have a chat. It wasn’t the best weekend as they were preparing for the RSGB SSB Field Day Contest but I had chance to make contact. I would have loved to stay around watching/helping them set but I was visiting my family in the afternoon.

During the visit I got chatting to my brother, who has inherited some of interest in radio, and convinced him to lend me his currently disused discone antenna, more on that later.

I also retrieved my old Binatone Worldstar radio which I got one Christmas as a child and got me well and truly hooked on the hobby. It doesn’t quite look at pristine as this one as it was heavily used and abused during my childhood. It lost it’s distinctive world map timezone cover, the handle, antennas and earphone socket were broken and clumsy repaired and it has spent nearly two decades in my late fathers shed/workshop. To say it is looking a little bit worse for wear is an understatement but I hope to restore it, it will never be back to it’s former glory but it would be nice to honour those childhood memories.

On Sunday I did have a good clean up in the workshop, things are packed away in boxes and stored on shelves now, at least I can now get into the workshop without clambering over junk and can find tools now!

During the afternoon I left the scanner and pc monitoring the ARISSat-1 frequency and got this image on the late afternoon pass.

At the time of the pass I was actually up in the loft dimantling the majority of my ‘antenna farm’ (some of them are deaf and not worth the coax) and installing the discone (it is as high as it can go in the loft space). I haven’t been up the loft for a while but was shocked by the amount of stuff up there. I did some rearranging but I really need to have a good clear out.

Well I can report the discone was worthwhile and while I have only used it for a few hours it certainly has improved my reception. I am now hearing the lower power mobile transmissions as well as the more powerful base transmissions from a number of more distant sites. The 70cm/2m amateur bands were also much more active last night and the RAF Waddington Radar is coming through much more cleanly.  

The discone is a Sirio SD 1300 U and I feel my tinkering in the future will be a bit more productive.

More SSTV images from space

After the success earlier in the week have been trying to get some more images from ARISSAT-1 as it passes near or over the UK during the evening. However reception hasn’t been quite as good.

The signal has been dreadful and the passes have been very short lived, not sure if it is the satellite’s performance falling off, interference or just bad luck. The only really decent image I got was another of the project logo. Really would so like to get a decent image from one of the on board cameras, had one almost image but far too much noise to make anything out.

8 years ago – UK139-L

The other day while hunting around for a home made programming cable for my Alinco DJ-X3 I found this odd looking box hiding in the bottom of a drawer

It is an eQSO/Echolink PC interface which I built 8 years ago when I set up a PMR446 eQSO Internet Gateway. The Gateway which was designated UK139-L was short-lived mainly due to the fact no one ever used it and it required a dedicated computer running 24/7.

My recollection of that period is a little vague but licence free PMR446 two-way radios had been around since 1999 and around 2003 was when they officially replaced the Short-Range Business Radio (SRBR) service and had become more mainstream and a lot of hobbyists saw them as a replacement for CB radio. Shops like Argos had started selling them to the general public (many of the dog agility shows I attended used them for across site communication).

Obviously being a geek interested in radio I decided to get some and when I found out about the scheme to connect gateways using a VOIP system to allow people to talk all over the world I couldn’t resist. With my usual enthusiasm I set about building one, testing it by driving around the local area and even created a website on the now defunct Geocities.

I will have a backup of the website somewhere, but as it turns out it was one of the pages archived by the Geocities.ws project. I have downloaded it and mirrored it on my current website at UK139-L Newark-on-Trent Some of the internal links are broken (not sure what version was archived) but I will fix it in the near future.

It has been years since I last looked at PMR446 but it seems the original website that coordinated the whole eQSO pmr446 project www.446user.co.uk has shut down and the official eQSO project appears to have reverted back to be just amateur radio based. However there appears to be an unofficial eQSO PMR network and an alternative in the form of the Free Radio Network

I will have to do more research and perhaps even resurrect the gateway when I get around to kitting out the shack.

ARISSAT-1

It has been nearly a year since I last posted, and what a year it has been.. but I digress.

Still tinkering with my radio scanners when I get the chance and over the last few days have been satellite hunting.

The ARISSat-1 amateur radio experiment was manually deployed on 3rd August 2011 from the International Space Station during EVA 29. Following on from the earlier SuitSat experiment ARISSat-1 was designed, developed and tested by AMSAT-NA and ARISS volunteers. It’s primary mission is STEM (Science, Technology, Engineering, Mathematics) education around the world.

The idea of the satellite is students should be able to easily receive the 2m FM transmissions as it fly around the globe and use the information in classroom exercises. The transmissions consist of voice message, SSTV images, telemetry and CW beacons.

Certificates will also be issued for SSTV image reception, voice and telemetry reception, CW reception, full SSB telemetry packet reception and Kursk experiment reception. The satellite has four cameras on board that will constantly be taking pictures and sending them to earth using SSTV Robot-36 format in the 2m FM transmission.

The official Web site for the ARISSat-1 project is arissat1.org .

Well I decided I would have a go and using my Realistic PRO-2006 scanner and my homebrew wideband antenna up in the loft have spent the last few evenings trying to pick up the transmissions as it heads over the UK.

The best reception so far was on the 21st August during the second pass of the evening where I got a decent amount of voice transmission and was able to decode a frame of SSTV (pictured above). I put the audio up on to soundcloud.com as well as youtube.

ARISSAT-1 21 Aug 2011 by nerdsville

Unfortunately the satellite has suffered some problems with it’s on board battery and goes silent/resets when it enters the shadow of the earth, which is problematic for reception in Europe as the current passes are occurring late evening.

There are a couple of decent passes this week, so hopefully can get some more intercepts and maybe decode some telemetry using a borrowed Alinco DJ-X10 which has SSB mode. Pass details for your location can be found here

Hamfest 2010

Took the afternoon of work today and went to the Newark Showground for a few hours to experience the National Hamfest 2010 Despite the weather which was absolutely appauling I had an enjoyable time. I resisted the urge to purchase any new equipment, this was difficult as some very nice receivers, scanners and antennas were on sale.

Because of the rain the intended outdoor carboot section was almost none existant which was a pity as I fancied a rummage. Inside it was mostly new ‘expensive’ gear a few surplus stores and a few clubs and others with some used and ‘junk’ stuff for sale. It is quite noticable that the cheap chinese import transceivers that are flooding ebay were also much on offer and I suspect if I do take the exam and get my licence I will end up with one of those initially.

In the end I picked up some adapters, a few books and I did take advantage of the RSGB special offer and joined up. I also signed up for the Group for Earth Observation (GEO) the members on the stand were very helpful and this was particularly interesting as the members of the group use relatively inexpensive equipment to receive data from satellites to produce weather images and other earth observation. I dabbled many years ago with receiving data from the NOAA polar orbiting APT satellites which can be done to a limited extent using a normal scanner and a PC soundcard. It was only £20 to sign up and the welcome pack for GEO was extremely generous and consisted of the last four quarterly magazines packed full of information and pictures and a lovely book all about the EUMETSAT system.

Station Report

It has been a few weeks since I dug out my neglected scanners and despite not being able to spend hours with them I have still had an enjoyable time reacquainting myself with them and experimenting.

Despite the growing use of digital transmission systems there is still a lot to listen to on the airwaves. I should note at this point that using a scanner to monitor anything that is not intended for ‘General Reception’ is illegal.

The Amateur bands are fairly quite around my location, however I was pleasantly surprised to be able to here to receive a number of Amateur repeaters both on the 2 meter and 70cm bands despite appearing to be outside the predicated coverage.

The CB bands are also very quiet but I suspect that is more to do with the high levels of interference I seem to be suffering. I have been struck by the apparent increase in interference (QRM) on a lot of the bands since I last used the receivers. I can hardly hear anything on the short wave HF bands except the more powerful commercial transmitters.

I suspect this interference is down to the proliferation of computers and associated peripherals, wired and wireless networking. Energy saving fluorescent lamps and microprocessor system in all manner of consumer equipment such as TVs, PVRs, DVD players for example means the airwaves are full of noise.

The Radio Society of Great Britain (RSGB) who represent the thousands of Amateur radio operators have begun to campaign to save the radio spectrum from such interference, specifically they are currently campaigning against the threat poised by the proliferation of PLA/PLT devices (such as HomePlug) these devices use the house mains wiring to transmit network data. However what happens is the wiring then acts an effective radio antenna transmitting the traffic at such levels blocking out other legitimate radio transmissions. This sounds(sic) to be in direct contravention of the EMC Directive of the EU that prohibits the manufacturer of any device that interfers with radio and telecommunications equipment.

However despite representations by the RSGB, the BBC and others OFCOM and the last Government have dragged their heals and refused to act. Hopefully the new Collation Government will be different, but I won’t hold my breath. More information at UKQRM
  
However given all this noise there are still things to listen to, of course I haven’t since it is illegal, but if I were so inclined there are plenty of analogue VHF/UHF Private Mobile Radio (PMR) systems still being used by commerical organisations. Such as taxi firms, councils, security patrols or by large business to facilitate communication across sites.

In the past it would be difficult to know the source of the transmission often listening for clues to try help identify them such as names of locations, buildings, streets and people for example. However nowadays it has been made a little easier by OFCOM who have allowed on-line access to the Wireless Telegraphy Register database. The use and allocation of radio frequencies is strictly regulated so now if get a hit on a frequency it is possible to use the WRT website to help identify them.

The air and marine bands are still as active as ever, given my location near to a number of RAF bases it could prove interesting if I were also so inclined.

Ladybird Book – The Story of Radio


I have just successfully bid on ebay for a copy of The Ladybird Book – The Story of The Radio I was browsing earlier and stumbled across Tony Ling’s website and it features an altered picture of the front cover and it sparked some nostalgia.

This was a book I was given as a child and remember being enthralled by its contents. As the blurb says the book tells the fascinating story of radio, from the early forecasts of James Clerk Maxwell and the experiments of Heinrich Hertz and Marconi to the modern Post Office Tower (remember it was first printed in 1968) and the use of radar.

Just got to wait for delivery…

I might go looking for a copy of the 1972 Making a Transistor Radio and might actually have a go at building one, but there are some pitfalls in it’s design!

Rebooting a lapsed hobby

My current equipment

Ever since I was old enough to handle a screwdriver and a soldering iron I have had an interest in radio communications and electronics. I spent many a hour in my childhood scanning the Medium and Short Wave bands with various receivers (usually scavenged from family, neighbours or saved from the dump!) I constructed numerous long-wire and other bizarre antennas. I even did a presentation on my hobby for my English Language O-Level exam – I really did confirm my status as a weirdo!

I played with borrowed CB radios and would have loved to progressed into owning one or becoming a proper radio amateur but unfortunately I simply didn’t have the money.

Then the home computer revolution started and my Dragon32 and Tatung Einstein took up most of my time. I left school and went off to University and when I came back home and got a job I spent some of my money on a new fangled radio scanner, a Realistic PRO2022 from Tandy.

A scanner is a radio that covers a wide frequency range, they are controlled my microprocessors and allowing you to listen in to a huge range of different communications including air traffic control, hobbyists (Citizens Band, Amateur radio), security guards, taxi’s and a lot more. Back in the late 80s, and early 90s they also allowed access to the emergency services and the old analogue cellular phones! Connecting it up a computer and using some software you even decode pager messages!

Gradually all the ‘fun’ stuff disappeared, the mobile phones became digital, so did the emergency services. This along with other commitments, such as moving across the country to a new job, getting married and other demands on my time meant the scanner ended up collecting dust in the attic.

Several years ago I briefly dusted it off and brought a couple of other second hand scanners including a Realistic PRO2006 and a brand new Alinco-DJ3X. I also played around with some PMR446 systems, but sadly again they all ended up collecting dust.

Well once again they are out of the boxes and I am having a fun time scanning around for interesting signals, well if you can count listening to the radio microphone at a local church interesting!

I am thinking of buying a CB as it seems to have evolved from the bad old days into something more grown up. Even becoming a DX amateur type system using something called freebanding not legal mind, but then technically using a scanner isn’t!

I am even contemplating taking the Radio Amateur exams and actually achieving a childhood dream, well I do now have access to money and did do an electronics degree!

This time I hope it doesn’t all fizzle out and it is looking more promising as plans are a foot for me to have my own shack and I won’t be spending as much time on my other hobbies next year.

BBC Radio Science Fiction Season

It has been an interesting couple of weeks for fans of sci-fi on the BBC Radio network. The digital only station BBC 7 regularly broadcasts science fiction drama, but has been joined by the mainstream stations Radio 3 and Radio 4 for a season of science fiction. The season consists of new dramas, dramatisations and readings of ground breaking books inspired and written by some of the greats including H.G. Wells, J.G. Ballard, Iain M. Banks and Arthur C. Clarke.

I particularly liked the productions of Clarke’s masterpiece Rendezvous with Rama, and Iain M. Banks’s State Of The Art. I do agree with Kate Chisholm’s review in The Spectator where she laments the loss of the Radiophonic Workshop’s unearthly sound effects and audio treatment that were once a staple of radio drama, they would have added a lot to the State Of The Art, but it was enjoyable none the less.

Wasn’t quite so sure of the apocalyptic The Death Of Grass drama bizarrely broadcast during Woman’s Hour While the story and production had merit I thought the casting of David Mitchell as the narrator wasn’t quite right, but then I recently spent several sessions catching up with his comedy Peep Show.

I read somewhere (but have lost the link) that the BBC received a number of complaints about the trailer (above) that they used on TV, seems it frightened a number of children! Not sure it would have got the same reaction as the original Exorcist Maze Game did…


I have embedded a ‘copy’ as the original youtube video has embedding disabled!