Radio Antics

Wednesday, 14 September 2011

SSTV on PMR446

Following on from my experiments in receiving slow-scan television (SSTV) from the ARISSat-1 satellite I was intrigued by the prospect of actually transmitting and receiving some images myself.

Being unlicensed the only legal equipment I can used is PMR446 these are low power (500mW) handheld transceivers with very limited range. I have several some older models kicking about from when I built a eQSO internet PMR446 gateway.

The SSTV image is transmitted by frequency modulation using a varying audio tone to indicate different brightnesses. The software I have been using to decode SSTV is MMSSTV by JE3HHT (Makoto Mori) It can also be used to transmit SSTV images by connecting the audio output of the PC to the transmitter audio in. It allows editing and customisation of the images and the encoding format to use.

Obviously I couldn't carry a PC around so instead I generated some images and recorded the generated sound to a WAV audio file and then used an old cheap MP3 player (which supported WAV files) connected to one of the Audiovox PMRS-838 handsets, configured to operate in VOX mode.

The plan was to drive around to a number of local high spots and with the transceiver on the dashboard of the card output a series of images and see if they could be received and decoded back at base! - Each image taking around 2 minutes to transmit.

The base receiver was my Alinco DJ-X3 connected to the loft based discone. I had to use the DJ-X3 because it supports to 6.25kHz narrow band channel step required by the PMR446 channel allocations.

Well the first set of results today have been pretty good, I went to three sites to transmit from and using the terrain profiler on HeyWhatsThat.com I could calculated any obstacles in the line of site..The base is on the left hand side, the transmission point on the right of the diagrams below.

Site 1, was 0.9 miles from home This site is just across on the other side of the Trent Valley with no significant buildings in the transmission path.

Photobucket

as you can see the five images all came across very well, just a slight sync error on one.

Site 2, was 1.2 miles from home and is one of the local high spots. Unfortunately there is a housing estate on the top of the hill. It is possible to go by foot on some footpaths to get into some fields with a clear vantage point across the town and down the Trent Valley towards Nottingham. However today these were from the car parked up near to the edge of the estate. I just sent two images - and they are a lot nosier.

Site 3, was 3.2 miles from home and is on a slight high spot across on the other side of the Trent Valley. I parked up in a layby and transmitted three images and really wasn't expecting much. So was very pleasantly surprised by the high quality of the received images, as you can see there isn't any geographical obstruction but there is a very big new power station at Staythorpe in the line of transmission which I expected to cause some issues. Some of the lines of noise on the images I suspect were caused when large lorries and vans were passing by on the road momentarily blocking the transmission path as it is quite a busy road.

From these encouraging results definitely some more experiments to be done on this, and some tests further afield!

My final images from ARISSat-1

It has been a fun month tracking and attempting to catch images from the ARISSat-1 satellite. I have succeeded in catching some decent images from the on board cameras (which I have previously posted) I was just missing the second elusive ident image, well yesterday my unattended station managed a noisy capture (as well as yet another of the other ident!)

13th September 2011 - 10:03 (BST) 09:03 (UTC)

13th September 2011 - 14:57 (BST) 13:57 (UTC)

I will not be attempting to capture anymore, instead I am starting some experiments myself with SSTV using some PMR446 equipment, I will keep you posted.

Monday, 12 September 2011

Digital8 - Digital Obsolescence

I suspect like many people I have numerous boxes of camcorder video tapes acquired over the years, some are the older 8mm video format and the later ones being Digital 8mm. Many of the videos are recordings of me running my dogs in agility competitions and others are the normal holiday type, obviously they all have a strong sentimental value.

A few years back I had made a start in archiving tapes onto DVD but didn't get too far because of time and other commitments.

I was already acutely aware that the Digital 8 format had almost gone the way of Betamax with Sony not producing any new cameras and was aware should my trusty used and much abused Sony camcorder fail I would unable to view them. However the bewildering range of current equipment and the move to hard drive base equipment filled me with dread and I'd kept put off making a decision on a replacement and continued to use the camera as normal.

Well the enviable happened a few week back and the camcorder started exhibiting playback issues, lots of coloured mosaic banding.

Thankfully eBay came to the rescue and I've finally managed to get a good condition used replacement camera at a sensible price. It is obvious I am not alone in this predicament given the frankly amazing prices some other auctions finally went for.

Now I can transfer them to DVD, but there are still worries that these might not last, so I will probably transfer them to some large hard drives, but how do I format them.... it's never ending...

Friday, 9 September 2011

ARISSat-1 Images for 8th September 2011

Two images, first pass at 13:27 BST - Another one of the ident

second at 15:04 BST, shame about the noise as it was almost a full frame view of the earth below!

Thursday, 8 September 2011

ARRISAT-1 featured on Ham Nation video podcast

Checking the ARISSat-1 website this morning and saw that Steve Bible (N7HPR) one of the technical team was being interviewed by TWiT.TV for the Ham Nation video podcast. Very interesting, starts about 25 minutes in.

ARRISat-1 Continues to broadcast

The 4th September marked the first month of operation of the ARISSat-1/Kedr spacecraft and despite some early worries has continued to broadcast.

Following the installation of my new antenna I have had some successful SSTV captures of images from the onboard cameras, including two from the same pass.

5th September 2011 - 1348 UTC

5th September 2011 - 1350 UTC

7th September 2011 - 1502 UTC

Monday, 5 September 2011

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.

Friday, 2 September 2011

Looking forward to the weekend

The last few weeks have been dreadful, for quite a long time I have been suffering pain in my left side and other issues. Various visits to the doctors later I was referred to a hospital consultant with suspected diverticulitis.

In the meantime I was away on holiday in the caravan near Barnard Castle last month when I was stuck down with really acute pain, so bad I collapsed and was taken off to Darlington Memorial Hospital for a four day stay. The provisional diagnosis is diverticulitis following a CT scan. I was discharged with antibiotics and told to take it easy. Well of course due to work pressures I couldn't and have not really recovered and I have had some more complications which good taste prevents me from detailing. Thankfully I am now on a new course of treatment and hopefully I will improve.

If I feel well enough this weekend I will finally make a start kitting out my new workshop/shack. We have had a complete makeover in the garden this year with new drainage, patios, lawn and some serious landscaping around the pond. Our somewhat battered summerhouse has been restored, painted and furnished and new electrics fitted.

A key part of this makeover was to replace a shed with a big (16' x 10') workshop, it has been divided into two sections one 6' x 10' which is the shed replacement and the other 10' x 10' which I was going to turn into my workshop/den/shack - all my 'junk', tools, radio stuff and computers would be housed in there giving me a refuge.

Unfortunately due to other demands I have made no progress getting it fitted out, but hopefully this week I will get the chance to make a start. If nothing else I will get hopefully give it a much needed coat of preservative as 8 months of sunshine has bleached it somewhat.

Thursday, 1 September 2011

Nice ARISSAT-1 Capture

Left the scanner on and the PC running MMSSTV hoping to catch a ARISSAT-1 pass this evening, but as it was it caught one as it passed over at 14:38(UTC)

Wednesday, 31 August 2011

HF weather facsimile decodes

Following on from my experiments with SSTV decoding from the ARISSAT-1 satellite I decided to have an attempt at decoding some weather facsimile transmissions.

Known alternatively as radiofax, hf fax and weatherfax these transmissions were the forerunner to SSTV transmissions and are intended for marine navigation and weather forecasting. Using the short-wave HF band transmission they still enable information to be received by vessels out of range of modern internet communications. Some Japanese stations even use the technology to transmit newspaper images. More details of the technology and the history at http://en.wikipedia.org/wiki/Radiofax

These transmissions use single sideband and frequency modulation. The signal shifts up or down a given amount to designate white or black pixels. A deviation less than that for a white or black pixel is taken to be a shade of grey. With correct tuning (1.9 kHz below the carrier frequency for USB, above for LSB), the signal shares some characteristics with SSTV, with black at 1500 Hz and peak white at 2300 Hz.

It is fairly simple to decode using a computer sound card and there are many software solutions available, however most are commercial products and have severely limited trial versions. I have used the free WXFAX software, intended primarily for weather satellite decode (more on that at a later date) it can be configured to decode the FM-120 signal. Details here http://www.newearth.demon.co.uk/radio/hfwefax1.htm

Some more useful links about the broadcasts at Marine Weatherfax NOAA broadcasts including a schedule of internal transmissions and stations (pdf) and also the German Deutscher Wetterdienst

Here are a few decodes made over the last few days on my Picasa Web Album

HF Weather faxes

From Please Ignore

To decode the signal require a SSB receiver I currently have in my possession a Alinco DJ-10X which has never excelled at HF frequencies and is very susceptible to overload and computer interference (it is more a VHF/UHF scanner) and has proved problematic in the past when using any data decoding using a sound card (suspect due to the heavily filtered audio output) but has been surprisingly good over the last few days. I am not using a dedicated HF antenna, but hasn't been too bad since the signal is coming from Hamburg (on 7880kHz) and is fairly strong in the morning but performance falls off during the day.

From Please Ignore

Decoding in action

Saturday, 27 August 2011

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.

Friday, 26 August 2011

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.

Tuesday, 23 August 2011

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

Friday, 15 October 2010

The stress of dog ownership!

It has been a stressful week at château Nerdsville. Our youngest dog Eddie (a two year old Pembrokeshire Corgi) became seriously ill Monday night.

We were woken at around 1am by the retching sound of something being sick and the pungent smell of you know what! I went downstairs to discover a pile of white foamy vomit in the hall and a small pile of diarrhoea in the kitchen near the back door and a sheepish looking Corgi.

I wasn't overly surprised as Eddie had been off his food and had already had a slight case of the runs when out for his afternoon and evening strolls the day before. So I let him out into the garden and set about cleaning it all up. We all retired back to bed only to be disturbed again at 5am by the sound of a dog running down the stairs and whimpering. I grabbed by slippers and dressing gown and hurried down to find Eddie in the kitchen again. This time I was also met with two largish pools of what initially I thought was urine but as I mopped them up it was obvious this was water with a dilute trace of blood (and was from the bowels as it smelt of faeces)

Eddie was out in the garden again and I found him squatting releasing a jet of liquid from his rear. This wasn't looking good, but have had dogs for many years and have experienced all sorts of stomach upsets. Given the time of day I decided it wasn't worth going back to bed and decided to sit up in the living room with the patio door open to allow Eddie to quickly get into the garden if needed (and I could catch up on the latest downloaded episode of Dexter on the XBMC).

For a while Eddie seemed okay, then at around 6:30am he ran out again to evacuate another jet of liquid. It was starting to get light and I could see that it was bloody again. The wife who was understandably worried reluctantly went off to work at around 7:30am and I went off to shower and dressed and planned to ring the vets to take him to morning surgery. However when I came down stairs I found another red pool in the kitchen this time it had the consistancy of pure blood, this was now getting serious and I rang the vet and was told to come in straight away.

I had already checked on the internet and my suspicions were confirmed as Eddie was diagnosed with Hemorrhagic gastroenteritis (HGE) This is serious potentially life threatening condition and the cause in most cases unknown but there have been a cluster of cases in and around Nottinghamshire our vet alone had seen three dogs in the last week one of which had nearly died. We were aware of the warnings concerning Sherwood Forest, Clumber Park and other woodland sites but had been no where near them for weeks.

Thankfully following a number of anti-inflamatory steroids, antibotics and anti-emetic injections Eddie has started to make a good recovery, thankfully it was caught early enough so he didn't need any IV treatment. He still isn't back to full health yet, but is much much better.

Monday, 11 October 2010

Jean Michel Jarre

I came down with a severe case of man-flu early last week but recovered sufficiently to travel to Birmingham and The National Indoor Arena on Friday evening to see Jean Michel Jarre in concert. We almost didn't go because I was still feeling unwell and the wife is having problems with her back and was recovering from an epidural steroid injection. I was glad we did go as it was a good night and a very impressive show both aurally and visually, just wish venues could see their way to giving an extra couple of inches legroom!

I had read in a pithy review of an early show that Jean Michel was actively encouraging the use of digital cameras and iPhones during his preformance so decided I would take my aging Casio EX-Z120 digital camera along. Arriving at the NIA we were met with signs banning the use of ALL photographic and recording equipment! Despite this I managed to take the camera in unchallenged and so did many others judging by the vast number of illuminated LCD viewfinder screens visible in the audience during certain parts of the performance.

One slightly annoying point of the evening was one particularly over-zealous steward who seemed to spend the entire evening tapping people on the shoulder or shining his torch into the faces of anyone who dared tried to make a digital memento of the evening - thankfully I was too ensconced in the crowd and was a little less obvious in my actions for him to pick me out, but he did target someone sitting just three seats away!

How ironic then on the last song of the evening Jean Michel did indeed ask the audience to send out a signal using their cameras on Facebook and YouTube! Unfortunately at this point I had already exhausted my memory card (I hadn't took my spare!)

I have uploaded a number of short highlights onto my YouTube Channel.

Sunday, 3 October 2010

A bit of a clean up and some repairs

The original plans for the weekend were thrown in to the air for a number of reasons. I spent most of Saturday with a saw, drill and screwdriver rebuilding part of the summerhouse in the garden and ferrying the old rotten parts and other garden waste to the local refuse tip!

Today (Sunday) I had the house to myself as the wife was off visiting her sister. As the weather has been absolutely atrocious, raining most of the day, I decided to have a bit of a clean up in the den. I'd noticed the fans in the main computer have been roaring under the slightest load recently and as I suspected the reason was the air intakes were blocked with dust and dog hair! While not quite as bad as these it was still pretty shocking as I do regularly check them.

As I had to pull them out from under the desk I decided to have a bit of a rearrange. While doing this I removed a redundant ethernet switch and an unused USB 1.1 hub, both were cheap far-eastern ones purchased many years ago. It now turns out they were a major source of interference on my scanners!

Photobucket

The tidy computer centre (yes the external HD are sitting on a 1980 2001AD annual!)

One other task I achieved today was to replace the backlight on my Realistic PRO2006 scanner.

I purchase the PRO2006 from ebay about four/five years ago, I got it for less than £20 as it was advertised as for repair or spares. It was described as powering up with sound but because there was no display it couldn't be operated.

When I got it (in it's original box with manual) and opened it up it was obvious what was wrong as it appear to have spent most of it's life in a shed or workshop, it was full of fine dust (I suspect from sanding wood) and this has blocked out the LCD display! It also had flecks of paint on the casing. The paint was thankfully emulsion and was easy to remove I just soaked the plastic case in warm water for a few hours. I stripped down the rest of the unit and removed the dust with a can of compressed air and a brush, other than that it worked perfectly!

One downside was the display backlight had faded, the backlight on many of the Realistic desktop scanners is an electro-luminescent panel and their output fades over time. Today I finally got around to replacing the panel, it isn't as straightforward as it sounds as the spare part is no longer available but using the instructions found here I was able to replace it with a panel cut from a larger sheet purchased from Farnell.

Photobucket

The display panel removed from the scanner with original backlight

Photobucket

Original panel removed (top) and replacement panel cut to size (bottom)

Photobucket

The new panel in all it's glory!

Photobucket

The only downside is from this angle you can just see the connector on the panel.

The backlight is now really bright, in fact I have had the 'dimmer' switch activated because it is so bright! I also have a Realistic PRO2022 and the backlight on that is fading too, it is nowhere near as bad as the PRO2006 was, but you can see the marked difference below.

Photobucket

This shows the repaired PRO2006 compared to my PRO2022.

One other benefit of opening up the PRO2006 was I discovered a soldered connector on the shielding behind the front panel had come adrift. I have resoldered this and this has dramatically improved the reception and audio from the unit. Today has been a good day!

Friday, 1 October 2010

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.

Thursday, 30 September 2010

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.

Wednesday, 15 September 2010

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!

Monday, 13 September 2010

Rebooting a lapsed hobby

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.