Monday, January 26, 2015

Tweether not Twitter

Twitter is just vapid piffle. So it's a wonder to me that any new product or service of substance would knowingly chance that kind of pointless brand confusion. I'm looking at you Tweether. It's really unbecoming.  But their website begins with the phrase "Traveling Wave Tube Based W-band wireless Networks with High Data Rate, High Distribution, Spectrum, and Energy Efficiency."  They had me at wave tube. Their stated goal is as follows:
"The objective of the TWEETHER project is set a milestone in the millimeter wave technology with the realization of the first W-band (92-95GHz) wireless system for distribution of high speed internet everywhere. The TWEETHER aim is to realize the millimeter wave Point multi Point segment to finally link fiber, and sub-6GHz distribution for a full three segment hybrid network.. The TWEETHER system will provide... broadband connectivity with a capacity up to 10Gbps and distribution of hundreds of Mbps to tens of terminals"

Tweether isn't a couple college kids in the garage with a bit of inheritance. It's a project at Lancaster University funded by Europe's Horizon 2020 program.  The few quotes out there on the topic all seem to have come from either Prof. Andy Sutton, the Principal Network Architect or Claudio Paoloni, Professor of Electronics who is the Project Co-coordinator. Paoloni describes our current spectrum as crowded, even congested. The solution he says is to distribute traffic onto unused spectrum such as millimeter waves. This is a block of spectrum lying between microwaves and infrared waves. More here.


But they're not going it alone. You can see the complete list of "partners" here, but it includes: Goethe University, Universitat Polit├Ęcnica de Valencia, Thales Electron Devices, Fibernova, and OMMIC. Those last two are ISPs. Honestly I'm surprised there aren't more of them on board but that may be by design.

Not all the big players beleive in harnessing the millimetre wave (mmW) radio spectrum.  Tweether is intended to operate at 92-95GHz. In the US, this band is limited to indoor use form a fixed position. [SOURCE] Also average power density is limited to 9 uW/sq at 3 meters. Peak power density of any emission shall not exceed 18 uW/sq. By comparison Bluetooth is essentially operating at 3 watts.  But the University of Lancaster claims Tweether could deliver up to 10Gbps. The test started this month so I'm looking forward to field measurements.

Friday, January 23, 2015

The Pat Sajak Show on AFVN

Thom tipped me off to the existence of this. You probably know the name Pat Sajak as the host of the TV game show Wheel of Fortune. But before that he was a longtime radioman even briefly at AFVN. You can read more here.





Thursday, January 22, 2015

The Sad Tale of the KickSat Femtosatellites


It was a fine idea and they had a good plan, and just enough funding. But there are enormous graveyards dug exclusively for good ideas in our world. I'll warn you now that this tale has a sad ending.

The project was envisioned by Zachary R. Manchester. The idea was that there were advantages in the  low power and low mass of femtosatillites and picosatillites that might make orbital communications more economical and efficient. The idea isn't completely new. The airforce issued a report on the topic back in 2007. There was also project West Ford back in 1961, but let's not get into that.  He got his crowdfunded through Kickstarter. Zac asked for $30k. His Kickstarter campaign raised $74,586.


KickSat was not a production network. It was a test. Each Sprite femtosatellite was supposed to be able to transmit just a few bytes. I've read some of the submissions that were online and most were under 16 bytes in length. The little Sprites themselves were only about the size of a saltine cracker. The payload of 104 Sprite satellites was carried on a CubeSat on an ISS commercial resupply mission, SpaceX CRS-3 on April 18, 2014. But things went wrong quickly.  On April 30th the microcontroller managing the master clock reset due to a technical issue. This woudl delay the release of the individual satellites. This delay was detrimental. On May 3 Sac announced the impending doom of the project. More here.

The Master clock problem meant that the CubeSat couldn't release the 104 Sprite satellites before it burned up in the atmosphere. The unit was not designed to allow ground control to send a release command. Thsi is because the uplink radio used to trigger deployment were unable to power up. On May 14th CubeSat reentered the atmosphere and burned up. Accounts record that "virtually" all sprites were lost. However there was at least one message received.

Wednesday, January 21, 2015

The Radio Violin and Miscellaneous Radio Organs

I am amused with the existence of the Theremin. It is often claimed that it is the only instrument you can play without touching it.  That's not actually true. Excluding the human voice as an argument of semantics, the theremin is just the only one that is well-known. Early electronic instruments are most often bulky, clunky and difficult to use. All of these were tube-driven and had the downsides of being both hot and fragile. The
Theremin was pretty elegant compared to the others. Most people are at least passingly familiar with early keyboard-based devices. But there were many others more like the Marimbalite— a several hundred pound device containing more than 60 photo-electric tubes...early optical sensors requiring no direct contact to play. Steam-punk genius yes, but practical instrument, no.


I've found a number of these luthier's-nightmare devices in back issues of radio and electronics magazines: the Trautonium, Telepiano, Pianotron, the Syntonic Organ, The Polytone, the Electo-musical Trombone, the Radio Organ and the Radio Violin... Let's pause on those last two.

The Radio Organ contained no radio. Much like the Marimbalite, it worked mostly from a series of photo-electric cells. But in 1934 a lot of gadgets had the word 'radio' tacked on the front of them for marketing reasons. In 1934 James Nuttall and Fred Sammis built a "radio organ" from an old keyboard, tin cans, a loud speaker, a dishwasher motor, and photo-electic cells. The organ contains a film-track disc of recorded tones. Light passes through a shutter through disc and to strike the photocells and a tone is generated.There is little hardware on board you'd mistake for a radio.



The Radio Violin is a bit more elusive. There were two different "Radio Violins" written up in the 1930s. The first was in Radio Craft magazine December of 1931. The article was short but the opening sentence made it sound like the amalgam of violins and radios was some long heralded event: "Radio programs may now be received through the medium of the violin."  The small diagram that followed described the soldering and attaching of a earphone earpiece to the violin so that it's sound may resonate int he violin body. The violinist may then accompany the radio live. 

But there was another radio violin that debuted in August of 1934. It was written up by Modern Mechanix and Popular Science. That Radio Violin had no soundboard and consisted of only the exterior violin-shaped frame. the vibrations of the strings were picked up by a magnetic pickup much like a modern electric guitar. From the violin a cable then connected that signal to an amplifier and loud speaker. No radios were harmed in the making of this device.

Tuesday, January 20, 2015

Transcription Mystery Disc #249

This is an 8-Inch, paper-core, Wilcox-Gay Recordio. It's unlabeled and in rough shape. The acetate lacquer coating is spider-cracked throughout, and it's somewhat warped. Where metal-core discs can sometimes be carefully unbent, paper just cracks and de-laminates more with the application of force. Thankfully the recording levels were set pretty high on this recording and it can be heard well above the noise.

"You Come On Out"

As with most discs, condition improves as you approach the center. But with the outer-edge start being the standard (as it is here) much of the recording is in poor shape. I've edited out the worst of it from the start of the recording to spare your ears. Notably at the very end you can hear an emcee speak to the crowd. It appears to be a recording of a live broadcast but he only gets in three words before the recording ends "You come on out..."