DISCLAIMER: I have no association with UVB-76 station, neither do I have any clue what is the content I am relaying. I can only assure, that the signal is received on 4.625MHz AM-modulated 900km NW from supposed origin and retransmitted unaltered. In no way can I guarantee this service, nor be considered responsible of any content re-transmitted. The only purpose for this relay to exist is because lot of people who do not have equipment or are located too far from station seem to be interested about listening to it. Should the UVB-76 station- or transmission content owners feel violated in any way, please contact me at uvb76.repeater@gmail.com and we will work it out.

Note, that because of shortwave radio signal propagation specifics the station can be more or less reliably received from around 4pm to 6am GMT on summertime. It is almost 24h audible during the winter, with short "skip-zone" blank-out around 6pm GMT.

The USB feed is considered as main source of audio today, as the voice messages are much better audible there than on the AM stream. However, the buzzer sound from the AM stream is somewhat more pleasant to listen at, so both feeds are kept simultaneously.

Saturday, December 24, 2011

Sounds from Space

Hopefully many people visiting this blog enjoy sounds from radio as much as I do, so let me share a wonderful archive of DD1US about the recordings of various spacecrafts, right from the beginning of an era, Sputnik.

The sounds are really spectacular, especially considering how much effort and innovative thinking these simple recordings actually carried at the time and still do!

I still find it almost unbelievable, that more than 50 years after, the space programs in both countries starting it all, are on a verge of shutdown ...

What in heavens sake (pun?) happened to our dreams?! Is it really THAT much more important to let small number of ethically challenged but otherwise ingenious minds experiment with free economy, only to come to conclusion that if you steal and cheat, its not gonna work? And this picture above is only part of, what's it gonna cost to bail it all out ...

Sunday, November 27, 2011

Jazzsequence - The Signal, a Pledge

UVB-76 has been a great deal of inspiration for musicians around the world, resulting many beautiful tracks. If you think there is room for more, please check the link what was just sent to me today by a good old friend Margus, who' s one of the greatest analog synth fans I know and runs a after-life site for old Roland synths (http://www.wolzow.com/)

Its a pledge by Chris Reynolds (a.k.a. Jazzsequence) for rising $900 for releasing an album inspired from listening to the shortwave and UVB-76 in particular. As far as I understood, the money is going to be spent on couple of cool gizmos helping to make a music in a specific way, but its a reasonable cause nevertheless as far as I can tell :)

Tuesday, November 15, 2011

SDR MK1.5 'Andrus' Software Radio Design Finished!

Its done! I have finally finished the SDR MK1.5 design! For those not familiar with what I am talking, here is a little intro.

The Software Defined Radio, or SDR, sometimes also referred as Software Radio, is a new generation of radio receivers what allow the reception of the radio signals with your computer software. The Software Radio is acting like an interface between the antenna and your computer. I have created a more technical overview about Software Radio architectures on SDR MK1 page, but the basic idea is, that the SDR Receiver is receiving the high frequency signal from antenna, makes it a digital signal and does some pre-processing, like frequency downconversion and digital filtering. The processed signal is then fed to the computer (on our case through USB or Network interface) and then visualized, decoded etc. on the computer software. 

The long-over-the-schedule radio boards went finally into production last night. It has taken four months longer than originally expected for a very good reason: The first fifteen MK1 units on the field got very warm feedback, but even more suggestions of what and how could be done differently. Therefore getting the design updated was a endless struggle between adding things and making a decision what shall be left out for a reason or another.

Here is a short recap on a design logic the new radio follows.

There are three main areas the radio has evolved from the MK1 design:

- First, it is now just a radio of better quality. The long list of small technical changes (many of which can probably be appreciated only by RF professionals and radio amateurs) will altogether account to a better noise floor and more precise signal reconstruction. While this is not important for an analog transmissions that much, the people working on a shortwave digital domain, DX-ing and signal hunting will
hopefully appreciate it.

- Second, the radio is now having a network interface besides USB and a 32-bit 60MHz clock CPU from Atmel. Both additions will drastically enhance the received signal bandwidth and connectivity: We are now capable to process up to 820kHz bandwidth on single channel through network and get the much desired 192kHz through the audio interface. The added mobility what network interface together with PoE (Power Over Ethernet) extension possibility will give, can allow this radio to be called a "network antenna" adapter!

- Third major change in design logic is that the radio extension capabilities are much re-visited and the MK1.5 can now be treated as a motherboard for a future experimentation, would it be an extension boards by myself or your own creation. This includes the jumpers on few selected places what allow adding the new RF boards to the chain, would it be filters on downconverters, and the I2C, SPI, UART and GPIO connectivity. The radio, although being a diversity shortwave receiver right out of box, is also now also a great general ADC platform for future expansion.

One of the first extension boards the SDR MK1.5 will get to utilize this capacity is the Elonics E4000 based downconverter, what will extend the receiver frequency range up to 1.7GHz!

Here is an updated specifications for the SDR MK1.5

  • Dual Channel diversity mode shortwave receiver 
  • Receiving Frequency range 500Hz .. 31MHz both channels
  • USB Audio Interface, 24bit 192kHz
  • 10/100 EThernet interface, with PoE extension possibility
  • IF bandwidth through USB audio 192kHz
  • IF bandwidth through Ethernet 820kHz

Aah, and one more thing - I got a suggestion, that the radio is supposed to have a name. Oddly enough, one of the prospects suggested was my own, so here we go - The SDR MK1.5 is hereby named 'Andrus' :)

Tuesday, October 11, 2011

Our own little Wikileaks (and the story of the dog)!

So far there have been relatively little material surfaced about what the number stations really look inside. There have been photos of the now-abandoned transmission site at Povarovo, some pictures of antenna fields and some inside stories of the guys serving at the radio units during their military service, all presented on the ever-lasting radioscanner.ru Buzzer thread.

Yesterday, however, the material surfaced at this very same forum what gives us a first-hand glance on the life and work of the UVB-76 station during year 2005!


The published material is what seems to be the logbook of the UVB-76 station at Povarovo covering the period of October 3, 2005 until December 7, 2005.
The guy who posted it to the forum claims, that they found it from the same abandoned building pictured everywhere with the dog in front.
The logbook does not seem to carry any labels of confidentiality or classified stamp (the red marking on front says "SAMPLE" and is meant to show how to fill the log), but that does not make it less interesting for the crowd interested in UVB-76 inside story!

The direct link to the page-by-page archive of this document can be found at:

Talking of dog, there is a entry on page 008, from October 4:

It reads: "18:30 Guard dog has put on place on post 173"

So, it looks like the famous last resident of the UVB-76 Povarovo station, The Dog, has entered the service on October 4, 2005.

(Picture by Desert_Fox from radioscanner.ru forum)

UVB-76 Wired Article

This is a relatively old news already, but for the sake of completness here be the link to Wired article about UVB-76 and the blog :)


Great thanx to Peter, Alexa and Cameron for doing all the hard work on Wired side!

The feedback has been very nice and ihe number stations community at Priyom.org has gained a number of new members to welcome. Wish you all lots of intresting findings!

Saturday, September 24, 2011

VLF Experience

Yesterday morning the mistaken frequency field in PRIYOM scheduler made the prijemnik receiver to tune on to 0kHz for a while.

As there was a thunderstorm in progress (quite surprising for mid-September) the result was a beautiful display of EMI scattering, when surplus electrical fields discharged. The sound was more or less like a dolphin song, too bad I did not have a recorder on to provide an audio sample ..

The horizontal line at the bottom of the screen is a lightning strike happening, but please also pay attention to the very clear and neat VLF transmission happening at 18kHz region. This is likely a submarine communication and sounded like any other RTTY modulation.

Surprisingly, my magnetic loop antenna design seems to work very well down to the VLF region, making it a really nice and compact exploration tool as indoor urban antenna. The long aerial outside was absolutely mute below 50kHz and did not display any sign of VLF transmission other than static.

Tuesday, September 13, 2011

Beta-testing the PRIYOM.org scheduled feed

It has been for talks too long already, but the live Number Stations Radio is now here! The way it works is, that our number station community at PRIYOM.org has taken a number station broadcast schedules from ENIGMA 2000, their own monitoring results, hints and findings from other places, and created a fantastic Number Stations Google calendar based on this information.

The result is a comprehensive list of daily transmissions, and it is only logical progression to create a live, self-tuning feed based on this information! The main streaming resource is the new prijemnik justin.tv feed at http://justin.tv/prijemnik and unlike its UVB-76 counterpart, this feed comes with the audio. The mp3/shoutcast streaming feed is up and running as well, but as the shoutcast streams have around 20 second lag with most players because of buffering, justin.tv makes more sense this time.

It will still take a while for this feed to make out from the beta phase. Please do not expect it to be up and running all the time in upcoming months, as it is still working from my development desktop and shares the development SDR MK1 radio.

Please also note, that the entries with the duration marked as 555 seconds are actually 1 hour off, so the message is actually going to be transmitted one hour EARLIER than scheduler shows. (The time zone mathematics for the google calendar files are pain to implement and still take some time ..)
[Update 14.09.2011: Scheduler bugs should be more or less fixed now]

Meanwhile, enjoy listening to static and you will get some numbers read to you every once and a while! :) 

Friday, September 9, 2011

UVB-76 - Under a different callsign again - 94ZhT

It was almost exactly a year ago, on September 8, 2011 when UVB-76 (or UZB-76 really, as it was operating then) changed its name to MDZhB. Not sure if there is a system behind it, but today the station broadcasted its messge on 11.30UTC with different callsign once again - 94ZhT.

Here's the clip:

Friday, September 2, 2011

Another outstanding piece of UVB-76 music!

If for nothing else, then the UVB-76 transmitters have been worth keeping warm for inspiring people. And as the sound is what the transmitter sends, the most popular art form is of course music! :)

I think I absolutely have to create a page of UVB-76 inspired art and music for this site, as there are some pieces what are really spectacular what I have been collecting over time and what have been sent to me.

The latest discovery is the oldschool techno track what is definitely worth the floors some place Ibiza!

Tuesday, August 30, 2011

17 Moments of Spring

The year was 1973 when this (probably one of the most famous) Russian series was filmed. To all of us fascinated by number stations, I would consider this to be one of the mandatory films in collection!

It is definitely worth watching the whole episode (and the whole series on that account) to get the feeling of how the life of those, receiveing the number stations broadcasts for living, look like.

For those eager to fast-forward, you can go directly to a 1:01:00 towards the end to see, why this video is relevant here. But whatever you do, do not skip the end title music!

The whole show was recently restored and colored to a very good quality, but this one is having an English subtitles and is a whole first episode, so I will link this for now.

Don' t know how long it will stay in YouTube like this (its not my upload, so there is not much I can do), but please enjoy it meanwhile!

Mibbit and the UVB-76

Before going any further - If you happened to use the same Name/Password combination any place else than registering your nick in Mibbit UVB-76 chatroom, please change them now!

If you can not access Mibbit with your nickname, see instructions at

As you may have noticed, the UVB-76 is now linking to a different IRC host for chatbox than earlier.
The chatroom has become a wonderful resource thanx to its users and as far as Shortwave Radio and Number Stations information goes, it probably has the set of best people available in the whole world. Well, the ones who talk, anyway.

For the reasons outlined below, the community has decided to migrate from Mibbit chat channel #uvb-76 to a Freenode channel #priyom. This is pity, as Mibbit web client is way better quality then  Freenode client, but at least temporarily, Mibbit has lost its credibility among users. Therefore the chatbox is now pointing to new chatroom.

The #uvb-76 channel is kept, however, up and running, as it has much better look and feel and it does also asupport embedded justin.tv window. This is mostly important as I will be launching a new service, benefiting from having the justin.tv screen and chat running next to each-other. More about this later this week.

Now the details of, what has happened.

What happened two weeks ago is that Mibbit, the company/server hosting the chat, got hacked. The details can be found here: http://mibbitblog.blogspot.com/2011/08/update-at-risk-nickserv-nicknames.html

The short version is that Mibbit kept some old copy of users password database in one of the development machines and as is the case too often with development environment, this was not secured enough. Albeit, the passwords file got stolen.

It would not have been a problem, if it would not been a standard showcase of many DO NOT' s. First, the database was (or seem to have been) a plain-text. This is something what you never do these days, as you will severely compromize your users security. People often use same passwords all over the places and if something like this gets loose, it may cost someone his entire entity in cyberspace. (Beware - if any service is able to send you your password after registration, they are keeping the passwords the way they shouldnt. Passwords shall ONLY be stored in hashed form, what prevents them to be reverse-engineered from password file.

The second mistake Mibbit did was not to warn its chatroom owners that something like this has happened. The absent communication effectively prevented for any timely damage control to happen.

Friday, July 1, 2011

SDR MK1 Firmware V1.1 Released

The SDR MK1 Firmware V1.1 is released and can be downloaded from http://sdr-mk1.googlecode.com/
The source code is also available for downloading should anyone be interested of what is really happening inside.

I am strongly recommending for everybody to go through upgrading procedure as indicated in googlecode page, as the update will make quite a difference!

The major difference is in dynamic range, what was crippled with original (0.7b) firmware. Instead of the original 40dB, the radio has now, depending on working mode, the dynamic range from 82dB to 110dB with noise floors on -100dB and -70dB respecivly (measured with pure s1.9MHz sine wave feed into RF input).

The second channel is now also working with 12kHz bandwidth, but more importantly, the second channel can now be used for the noise canceling, i.e. the radio now has true diversity mode!

As finding the dynamic range bug took about a month worth of head-banging, the ExtIO DLL work has been delayed, but I am now able to get back to it!

Monday, June 27, 2011

Alexanderson Day on July, 3'rd!

For all of us loving the odd transmissions, one important date to mark in your calendars is July 3'rd 2011, the Alexanderson Day, where worlds only intact and working alternator type radio transmitter, Alexanderson Alternator (SAQ) is once again switched on at 9:00 UTC and 12:00 UTC, transmitting CW on 17.2kHz.

(picture linked from Wikipedia page)

The transmitter at Grimeton, Sweden, is a spectacular piece of equipment representing a true (and still working!) heritage of the very early days of radio. Its first transmission took place in October, 1924 and it has been air-worthy ever since. After the WWII the transmitter was becoming obsolete because of HF communications equipment taking over, but was put in use as VLF transmitter for submarine communication for Swedish forces. It was finally decommissioned in 1995 and although operating flawlessly, destined for scrapping, no matter that it was the only remaining working piece of its kind in the entire world. The small group of enthusiasts were able to save this fantastic landmark and we have now an opportunity to participate in its annual celebration.

For those equipped with SDR radios extending to VLF range, the exercise is as straightforward as receiving any other station.
For those not having VLF capable receivers in their possession, the following link may be a good starting point: http://www.qsl.net/dl4yhf/speclab/vlf_rcvr.htm

Basically, your favorite SDR software, such as HDSDR, Winrad etc. will do by just connecting a small piece of circuitry in your sound card input. I am not sure if just a long piece of wire (and may be a 17.2kHz bandpass filter) in your microphone input would do it from around the world, but there are reports that it has been working.

[EDIT: In whatever reason, I misposted the SAQ frequency in original post as being 17.9kHz. Now idea where this came from, but the correct one is 17.2kHz as the text now sais. Sorry for the mistake and thanx to IRC user jarod for pointing this out]

Saturday, June 18, 2011

SDR MK1 Radio has now Diversity Mode working!

I had people asking me over and over again, why is there no diversity mode for the SDR MK1, if I am using the diversity receiver chipset as the core of the radio ..?!
To be honest ... the idea just did not occur to me! I was so fond of the idea having two radio frontends, that the whole usefulness of diversity mode in urban area did not come to me :)

So, by a popular demand, SDR MK1 is now supporting diversity mode!

For those not familiar with the concept, diversity mode means, that you can use one channel of the radio with your ordinary antenna, while the other channel can be equipped with something receiving a background noise, would it be your own laptop power supply or neighbours plasma TV. The radio then subtracting the noise from useful signal, and you will get noise canceling.

In reality, it looks like that:

(The LO frequency is actually 4.625MHz, the display is just not in sync).
As you see, there is a clear distinction where the diversity mode was switched on and off.  The noise is coming from the halogen kitchen light power supplies in the apartment. The useful signal is received with magnetic loop in the apartment, the noise is received with short telescopic antenna borrowed from ICom scanner.

Please note, that this is not a universal remedy to receive anything from far away - it is not improving any gain, it is just a useful feature to cancel strong local interference sources.

Wednesday, June 8, 2011

Happy Birthday, Repeater!

It just occurred to me, that UVB-76 Temporary Internet Repeater has a one-year birthday today!
While the first tests were made already on 6'th, the 8'th of June is the date since the repeater has been up and running more or less non-stop.

It has been a rewarding time in every sense and I would like to thank all of you who have gathered around the repeater during this year - you are the best audience one web project could ever wish!

Thursday, May 5, 2011

Repeater temporarily down

Yesterday noon the internet connection got lost and ISP has not been able to restore it since.
I am trying to get the backup over the 3G mobile network up and running tonight, but if worse comes worse then we do not have the repeater untill tomorrow morning, as  technicians are scheduled to replace the ADSL modem then.

I will start working on a decent 3G backup connection now, seems that every two months there is a need one way or another for it.

Tuesday, April 26, 2011

25 Years from Chernobyl

Early morning 25 years ago, on April 26, 1986 the accident at Chernobyl power plant rendered the large area in Ukraine (part of the USSR back then) a nuclear wasteland.

From radio communications perspective, this location has also another outstanding object of interest - the notorious "Russian Woodpecker", located within 30km evacuation zone of the plant.

(Picture from http://www.blankheads.com/)

Tuesday, April 12, 2011

Happy Cosmonautics Day!

This is what Russian leading radio magazine "Radio" cover did look like in May, 1961 after man in space. If we could go back in time to April 12, 1961, we should turn our radions on 143.625MHz VHF  and possibly on 20.006MHz shortwave.
The somewhat naive representation of the space vehicle is not something the editor has put there for fun. The actual appearance of the Vostok-1 spacecraft was not revealed until the year later. The excellent article about the secrecy around the early space flights can be found Here.

And here is an absolute fantastic piece of music from Finnish band Milioonasade to celebrate this great achievement 50 years ago

For voices from space, an excellent archive of the recordins of various space vehicles: http://www.svengrahn.pp.se/sounds/sounds.htm

Happy Cosmonautics Day!

Thursday, March 31, 2011

SDR MK1 Shortwave Radio Receiver Alive and Kicking!

After almost memorizing the National Semiconductol LM97593 chip datasheet and getting intimate with the DSP registers setup inside, the SDR MK1 is now working!

NB! There are some minor changes to the schematic and layout on the SDR project page, I will post errata and new files in next few days together with software developed so far.

This is what it looks like when assembled :)


It has two channels, both equipped with 32MHz lowpass filter, so two different antennas can be connected to the reciver. Replacing the filter with the bandpass, any 30MHz frequency region between 5kHz and up to 300MHz can be acessed, as the rest of the chip is capable of handling this range. The power connector is only needed if your USB connector is not able to supply 500mA of power, what most of the USB ports will, but some dont. In that case you will need external 6V adapter.

Normally, the board is connected only through the USB what is supplying power to the SDR and is used to transmit audio feeds and control information.

Technical specs so far:
  • 5kHz to 30MHz frequency range
  • 0.02Hz tuning resolution
  • 123dB total dynamic range
  • 64MHz internal sampling rate
  • User Programmable AGC (automatic gain control) with enhanced Power Detector
  • 48kHz/16-bit output sample rate (upgradable to at least 96kHz/16bit in near future)
  • Compatible with most free SDR software, such as SDR-Radio, HDSDR, PowerSDR, Winrad etc.
  • Possibility for tuning and setup using serial port console screen
  • Powered from USB port or external adapter
  • 2x BNC Antenna connectors (Mfg: Rosenberger)
  • Max current consumption 470mA
  • Open software and hardware design for DIY development, filter upgrades etc.
  • Two channel digital downconverter (DDC) with integrated 12-bit
    analog-to-digital converters (ADCs) and automatic gain control
  • Double DVGA (digitally controlled variable gain) front end amplifiers with +36dB maximum gain and 600MHz bandwidth
  • RF filters: 7-pole Chebyshev lowpass filters
  • Channel Filters (DSP): Fourth Order CIC followed by 21-tap and 63-tap Symmetric FIRs

How well does it deliver? Well, the two receivers I am intending to compete with are Perseus from Microtelecom and SDR-IQ from RFSPACE.
Both are top of the class and share the same arhitecture as SDR MK1. I havent been able to play around with neither of them myself, but looking at the screenshots in the web, the MK1 measures up quite well, especially considering that the screenshot below is made with the very first set of DSP chain parameters what are not totally off, but are still far from optimal values.

This is what the UVB-76 looks on screen when received with SDR MK1

The screenshot taken last night is somewhat special, as it shows two signals visible next to buzzer. The top one is an encrypted voice traffic, referred as "Sailors Cry". The bottom signal is the Russian USB (open) voice traffic on 4627kHz what was very active last night and was part of the of massive commcheck around different radio posts in the region. The two may be related or may be not, but they seem to share exactly the same frequency.

Further left is the Tallinn Volmet  and some new "jet" type of transmission, what has appeared lately, harrassing it.

There is still some software work ahead on firmware to get the SDR audio output to at least 96kHz/16bit and possibly 192kHz/8bit. While I am now investigating if the 96/16 ispossible to achieve with AT90USB1287 processor with the standard Windows USB 1.0 audio drivers, both look doable with proprietary driver.

Sunday, March 20, 2011

UVB-76 on RADIAATOR Festival

Here are some pictures of the setup at the festival bar :) The radio is of course the R-250 with the power supply sitting on top of it. I took the liberty of borrowing one of the Karl's original forum logo versions and printed a small banner of it as well.
The strange hat with goggles in front is the ancient Russian vehicle driver gen1 night vision helmet brought just for a amusement and for headphones' sake. However, as the goggles are actually working (off the 9volt battery, in fact!), they got some quite heavy use :)

As an aftermath, dragging the radio to the site was worth every bit of effort! The reception was exceptionally good using the magnetic loop antenna exactly as described in the blog. It made surprisingly good 61m (4750-5060 kHz), 49m (5900-6200 kHz) and 41m (7200-7450 kHz) shortwave broadcast band antenna (another good reason for building it!) and also picked up buzzer crystal clear without any tuning of the antenna needed.

The overall amusement from the fact that anything such shortwave even exists, together with excitement of all the broadcasts received made it a nice conversation piece and reminded several people that once in the highschool they wanted to be radio amateurs, but have ever since forgot about that dream! The radio was also the ambience sound of the bar most of the time.

For everybody dialing through the wilderness of shortwave bands, here is a piece of recording I made at the festival. The group is called "Eesti Elekter" (Estonian Electricity) and the gig at the festival consisted of stage full of samplers, loopers, filters and whatever else, all fed by different transistor radios and processed live!
The result, I shall say, is stunningly close what we hear on a daily basis, so next time the noise you are picking up starts feeling like if someone has composed it, it actually may be! :)

Thursday, March 17, 2011

UVB-76 featured in RADIAATOR Festival in Tallinn

Just to let you know, that UVB-76 and its genre is represented in RADIAATOR Radio Art Festival in Tallinn today and tomorrow, at the Estonian Museum of Modern Arts.

The old faithful R-250 receiver is set up for overall amusement and shortwave listening experience at the festival bar room.
Three tracks what have been sent to me over time by different forum members, all featuring and inspired by the UVB-76 buzzer, are also played on the festival local radio show (broadcasted from the local umm.. semi-legal FM transmitter) and somewhere on the floor.

Just to have this collection available to everybody here, please find the tracks below. I think I have all the authors permissions to distribute, let me know if there are updated versions or additional tracks!


Tuesday, March 15, 2011

Condolences to Everybody in Japan

As the situation around the Fukushima power plant develops on the edge of possible meltdown, we can all only imagine what have the past few days have looked like for the nuclear engineers working on and off the site .. :(

Here is the piece fit to listen at the moment ..

The consequences of this disaster to the overall nuclear power developments are huge. Yet, do not forget that these reactors are ancient, all from the seventies. 


They have been designed at the time when majority of the industrial control was relays and majority of the radios run on vacuum tubes.. Certainly, their control systems have been upgraded several times since, but the reactors itself have more or less been running perpetually ever since.

Not being especially pro or contra of nuclear energy, I do sincerely believe the nuclear fusion reactors to be the future of the energy, see http://en.wikipedia.org/wiki/ITER.
The fact that electrical plant designed some 20 years after the first nuclear bomb test has gone out of hands after biggest ever in history earthquake has hit it, should not put the entire industry back in stone age.

However, I am afraid it does for a while ..

Tuesday, March 8, 2011

SDR MK1 Shortwave Radio Boards Arrived

To balance out the mishap with the cable, the first batch of the PCB´s for the SDR just arrived!

Somehow it did not look all that complicated when I was looking at the layout on the screen! :)

99% of the components have also arrived with the exceptions of some exotic parts like CPClare solid state relays and Minicircuits RF transformers (both are on its way tho).

One can guess three times what I am doing over the weekend ...

Temporary Outage of the UVB-76 Internet Repeater

And this is basically why:

The nearby construction site diged the copper out for some erratic rationale. Telco did a quick patch pronto, but today it will be another couple of hours down when they apply a proper fix.

Friday, February 25, 2011

SDR MK1 Shortwave Radio Shematic and Layout Update

The SDR MK1 project page has been updated with new schematic (v1.02) and has now also a layout with some explanations about what and how.

The PCB-s went already to production and I expect the boards and components arrive some time next week, so the moment of truth is quite near :) (Although the software will likely take several more weeks t polish).

As a sidenote, I just realized that having the dual channel shortwave software radio may be a nice thing, but having another channel tuned on utility frequency range would make it even nicer tool locally. With appropriate bandpass filter, we can nicely tune from 144MHz amateur band up to the 174MHz TV ch.7 with our 30MHz spectrum width, so it covers most of the open utility channels.

Guess I have to start designing a filter boad! :)

Wednesday, February 23, 2011

First version of the layout ready

Just for your amusement, this is what the PCB layout for SDR MK1 looks like! I will update the project page later on (new revision of the schematic etc.), this is just a quick glimpse.
The design is done to fit the milled housing, so its only 106x78mm in size ;)

Tuesday, February 15, 2011

Justin.tv ads

Please receive my apologies for the audio-visual ads you receive every time the front page is loading. Justin.tv has recently decided to cash in and while I have no objection of them doing so, it is extremely annoying to have such thing happening on a blog front page.

It will take some time (weeks, rather than months tho) to configure my own video streaming server up and running stable (I have tried at least 5 different webcam services, none of which are really suitable for unattended video streaming), so please try to cope with the situation meanwhile ..

SDR MK1 Housing

SDR MK1 housing just arrived! Big thanx to my brother, who did the CAD drawings and organized the manufacturing!

As a result, SDR MK1 is going to live inside 110x80mm solid milled aluminum block! It costs 70EUR to manufacture, but somehow it feels like money well spent! :)

It seems, that the SDR MK1 is more and more becoming an open source product of a sort, where one can build it totally on his own, order a bare PCB, order a PCB with some (difficult to assemble) components mounted and rest in a anti-static bag, order an populated board without an housing or have a complete radio delivered.

However, first I have to get the prototype running! Currently the PCB component placement is done and about 70% of routing is finished. I am still working with only two layers, so there is hope, but at least one area looks really tough at the moment (thank you National Semiconductor, for positioning three different power buses and internal analog filter caps all at the same side of the 128pin housing!!!), so it may end up with four layer board instead. 

Here are some pictures of the housing. Note, that it still has to go through glass-balling and anodizing to get this satin Apple-like look. At the moment it is as it came from the milling.

Sunday, February 6, 2011

SDR MK1 Preliminary Schematic

After several weeks in making, the first version of the SDR Mark1 schematic is finally here. Look at the SDR Project page, click "Schematic" at the index on left.

It may be a right time to apologise for the statements made earlier as "simple", "easy"  etc! :))
While in fact its not too complicated considering what it is about, I ended up with way more components than initially planned.
On the other hand, it has no cut-backs anywhere, so I can state that it is as good as my current knowledge of SDR design allows me to create.

Now to the PCB layout and then we shall see if it performs as supposed to!

Monday, January 31, 2011

USB for everyone!

Over the weekend, I was playing around with the USB interfacing for the SDR Mk1. And, to a great surprise, Monday, 1:30am I ended up with functional setup consisting of two serial ports and one 192kHz audio recording interface, all embedded inside one composite USB device living inside AT90USB1287!
What makes it really useful is, that it works under Windows7 without the need of any special driver - it manages with the internal ones.

It is unbelievable what Atmel with its AT90USB line and Dean Camera with his LUFA framework have done to USB world! Creating a working HD audio and two serial ports by totally USB-illiterate person with one weekend is a living proof that Dean is a genius and Atmel knows how to make chips!

Thank you, one step closer to a working SDR :)

Thursday, January 27, 2011

Working on the Atmel USB for SDR ...

Assembling the AT90USB1287 prototype board, listening to the fresh episode of the podcast meanwhile .. Life is beautiful! :) Thank you guys for another excellent podcast!

Sunday, January 23, 2011

SDR MK1 Progress - Cypress vs. Atmel

As most of the work is going on at the SDR project right now, I guess I will start posting the status updates here in blog and do not litter the project page with my thoughts about the life, universe and everything.

Anyway, much-awaited Cypress EX-USB FX2LP kit arrived couple of days ago.

After playing around with it for two full days, I put it in my drawer and re-designed the schematic for using Atmel AT90USB1287 chip instead.

Dont get me wrong - its a nice little $29 development kit and does what its supposed to. It works allright with Cypress development tools. CY7C68013 chipset has been used in many different products all around the world (including several SDR designs commercially available) and I havent heard bad words about it. But ... Cypress EZ-USB FX2LP platform its tad too sophisticated for something I am doing here.

First and foremost, its compiler of choice for C/C++ is uVision2, what is included inside development package in its demo form, allowing only 4Kbytes of code maximum. Not only is it a very severe limitation, but the uVision2 tools provided are also two generations behind the current breed of uVision. The the default demo for uVision4 downloaded from their site is further limited to only 2Kbytes of code, so it is practically useless for production. And the full version costs $2-$3K. As I have noone else to write that bill than to myself, this is no go. The alternative is the freeware SDCC compiler for 8051 CPU, but I have seen mixed reports about the usage of it for FX2LP.

Second, equally severe, problem is the examples provided with the development tools. Yes, they did compile allright. Yes they did load on the $29 development board. Yes, I got USB devices appearing on my computer. But ... what devices? Is it too difficult to provide at least one meaningful example of the USB device what would appear as keyboard or mouse on windows?? Instead, the example folder is littered with all sorts of hardcore stuff about the block transfers and different I/O methods on CPU and whatever else. Very clever, I assume, but not too useful for somebody who wants to implement simple composite USB device consisting of USB audio and virtual serial port.

Cypress EZ-USB was one of the very first chips on the market capable of USB2.0 and very fast transfers, but its support and toolsets have not been updated much since. If I would have someone I could bill the hours working on it, I would probably consider it more seriously. At the moment its 1:0 to the Atmel.

Atmel has recently produced many chips natively capable for USB connection in its 8-bit AVR line. More importantly, they have gained a user community support for implementing the USB devices (and hosts) using these chips.

The tool of choice for me is a framework named LUFA (Lightweight USB Framework for AVRs, formerly known as MyUSB), created by Dean Camera. It has all the essential devices, like USB serial, audio in and audio out implemented in its examples folder, and the toolset it uses is Atmel mainstream tools, AVR Studio 4 and WinAVR.

So you need to install these two (you dont need to install AVR toolchain, as GCC tools usage by LUFA are better compatible with WinAVR), download the LUFA and here we go!

Fortunately, the 64-pin AT90USB1287 is relatively pin-compatible with Atmega325 what I use in many designs, so I am able to mount it on already existing board I have and should not worry about the development kit. Chips are supposed to be arriving on Tuesday ..

Tuesday, January 18, 2011

All archive files are now online

Yes, it took 2 whole weeks non-stop to upload these, but all the UVB-76 Temporary Internet Repeater USB archives are now online!
The old ones are using GMT+2+1(daylight time) timestamp and really old ones are actually from AM feed, but this is what I've got from these days.
I am not sure, but this may as well be the largest shortwave radio recording archive ever published! :)
Although Hostgator (bless them!), where it is all hosted, has said that they do not have problem with 100Gbyte space usage as far as traffic is not too high, I would not like to push it too far, so at some point I will likely take some of this offline. However, I am trying to keep entire archive on hard disks here, so if you miss some specific recording, just let me know. 

Monday, January 10, 2011

Sample chips for SDR arriving from National Semiconductor

THAT. WAS. FAST. Amazing! I got e-mail from National Semiconductor on January 7'th saying that they cant ship samples on their own expense and I have to pay for the courier service. It was expensive as hell, but still much cheaper than ordering the same number of chips from DigiKey, so I decided to give it a go. I got confirmation from Singapore warehouse, that the order was shipped on January 8. I got a call from local UPS office today, January 10 at 13:24 asking if I am at the office! Thats less than 48 hours from me making the shipping payment to NSC till doorbell!

Guess I have to start designing now! :)