Wednesday, July 23, 2014

SCM SCR SCS

Just when you think you have all your jargon and technical terms down someone whips out an acronym you don't recognize.  The acronym SCM stands for Set, Complete, Meteorological. It's one of three related WWI Radio Signal Corps acronyms. More here.

  • SCM - Set, Complete, Meteorological
  • SCR - Set, Complete, Radio
  • SCS - Set, Complete, System
 The book World War II Battlefield Communications by Gordon L. Rottman covers this in some further detail. U.S. military radio equipment has been designated S.C. since 1909 standing for Set Complete.This may have distinguished it from radio parts in that era. This was a prefix to every model number. For example an SCR-300 was a portable radio transceiver radio used in WWII. The SCM-1 was a Mobile Meteorological Station used in the same conflict.In that context by the way mobile means vehicle mounted. More here.

There was also a huge number of two-letter designators for the components and accessories for all these units. Some were pretty obvious, AT indicated antennas, HS for headsets, LS for loudspeakers, GN indicated generators, BA indicated batteries. BC was less obvious,  basic components like a receiver. But RD stood for switchboards and EE for telephones, 

In 1943 still in the middle of WWI the military introduced an all new numbering schema. This was called the "Joint Electronics Type Designation System" aka the “Army-Navy System” or “AN System.” (It was not actually used by the navy.)  It was later changed to JETDAS with the inexplicable addition of the word "automated."  But thankfully they did not re-designate existing models. As time passed the new system was applied to new devices and as technology progressed those older units fell out of service.

Tuesday, July 22, 2014

Transcription Mystery Disc #223


This is a 6.5-Inch paper-core Wilcox-Gay Recordio brand acetate. It is in decent shape and relatively flat but has some marring from having been stored in a stack. It bears some light pencil markings "Dolores + eb + Les for Bev"  The other side reads "For Bev - By Dolores."  INcreasingly I have issues with paper core acetates. If you store them flat the surface mars from downward pressure. If you store them vertically they warp. There is no right answer. In this case the surface noise varies. I've adjusted the noise filter as much as I could but it's far from perfect.

 Shortnin' Bread



This recording is of two children's songs, the first is "Shortnin' Bread"  and the second is unintelligible. The tune Shortnin' Bread dates back to at least 1900, and probably longer.  It was documented across the south by 1925 attributing to that fact. This version was probably recorded in the late 1940s based on the make of the disc.

Monday, July 21, 2014

Low Earth Orbit Broadband Satellite

Google has generated a bit of press in the last week with their Project Loon and their funding of O3b Networks.  I for one am optimistic, but equally amused with the apt naming of a looney project. But internet from space is radio, and radio is something I know about. The big question remains.. is there any efficacy in  a space-bound ISP that can provide global connectivity? In a word?  Maybe.

These low earth orbit broadband satellite ventures are promising nothing short of Satellite Internet access. But in a way, that has been the promise all along. The first commercial communications satellite was Telstar 1, built by Bell Labs and launched in July, 1962. The first satellite to successfully reach geostationary orbit was Syncom3 which was launched the following year. Telstar 1 had only one transponder to relay data. It operated in the C-band (4 to 8 GHz ) receiving 6 GHz microwave signals and responding on 4 GHz omnidirectionally. This was not going to move a lot of data. It did relay television signals, it's orbit only allowed it to do so in 18-minute segments as it whipped over continents 3,500 miles above the surface. Telsar 2 was identical, but the Syncom series that began launching in 1965 were at least geosynchronous.

But the real excitement came in the 1990s. In 1993 the Hughes Aircraft Co.asked the FCC for permission to launch a satellite that transmitted in the Ka-band (26.5–40 GHz.) This matters because there is a direct relationship between frequency and bit rate. Frequency is just the number waves per second measured in Hertz (Hz). So a 100MHz signal can transfer 100,000,000 wave cycles of current in one second, but that's only 0.1 GHz. Bit rate is the number of bits of data transferred in one second. We measure this in bits per second (bs.) If you imagine each wave as a bit you can see how increasing the frequency increases the bit rate. (Though clearly encoding schemes also increase speed.) Consequently moving from 6 GHz to 26 GHz was pretty significant for data transfer.

In 1995, the FCC opened up applications for other Ka-band satellites. Fifteen companies applied including: EchoStar, Lockheed Martin, GE-Americom, Motorola and KaStar Satellite.. one of the first that tried to offer ISP service was Teledesic. They launched in 1998 operating between 28.6 and 29.1 GHz. 9 billion dollars and 8 years later it went bankrupt. The project was totally abandoned by 2003. But that same year Eutelsat launched 31A which provided broadband services in Europe. First called e-bird and later Eurobird, it was renamed in 2012. it's still in service. Anik F2 went into service in 2004 delivering a similar service to Canada, but was capable of a very impressive 140 Gbit/s with 114 transponders.  Of these 50 operate in the Ka-band, 40 in the Ku-band (12–18 GHz), and 24 in the C-band. That was a decade ago. In more recent years, ViaSat-1 and HughesNet’s Jupiter have proven capable of data rates of up to 15Mbit/s. That's better than I get from my cable provider. (ahem) There are now a slew of these high throughput satellites.
  • Anik F2 (2004) 
  • Thaicom 4 (2005) 
  • Spaceway-3 (2007) 
  • WINDS (2008) 
  • KA-SAT (2010) 
  • Yahsat Y1A (2011) 
  • ViaSat-1 (2011) 
  • Yahsat Y1B (2012) 
  • EchoStar XVII (2012) 
  •  HYLAS 2 (2012) 
  • Astra 2E (2013) 
  • O3b Satellite Constellation (2013) 
  • Inmarsat Global Xpress constellation (2013) 
So back to Google and O3b.  Those satellite broadband ventures of the 1990s and 2000s didn't fail. They've created a cache industry in rural and third world internet service. While Microsoft's funding of Teledesic may have gone nowhere, so did Windows ME, Vista and 8. Google has a better track record for holding and folding. They also clearly have the bank balance to launch and support more high throughput satellites. This isn't something new, this is more of something we have already proven can be done. I, for one, welcome our new Internet overlords.

Friday, July 18, 2014

Rated KCPR



91.3 KCPR, Cal Poly’s student-run radio station, could be sold away from the campus following a fundraising promotion in which two male student DJs offered to sell photos of their genitals. Mustang news already gave their name so I'll just give that link here.  Cal Cost News covered it as well here, Campus reform.org, Huffington Post and a slew of other sites. In other words this was the proverbial shit storm. Radio DJs are attention-seekers.. but sometimes as an amateur you can become accustomed to having none, and operating under the assumption that "no one is listening." Per Murphy's law this is never true when you need it to be. It began with an April 21st facebook post from the program Getting It In:
“For only $20 dollars, you can have a week of sexy snapchats featuring the hosts of Getting It In! If you’ve ever been curious if which one of us has a birthmark on our penis or which one of us has a tighter butthole, this is your chance to find out!”
They have taken down their facebook page, closed their shared Google Docs, deleted their Soundcloud account, Mixcloud account. Nothing remains online but cached data. The chair of the Cal Poly Journalism Department, Mary Glick who is ultimately responsible for KCPR has started an investigation. As a result the 46-year old station is now in mortal danger.  University spokesperson Matt Lazier said the following:
“Journalism Department and College of Liberal Arts administrators are investigating the matter to learn the full extent of the facts and determine whether administrative and/or programmatic changes should be made to the KCPR operation. As well, university administration is investigating the matter to determine if any student conduct violations may have occurred.”


the Dean of the College of Liberal Arts Douglas Epperson, was even more to the point: “I am beginning to believe that we should sell the radio license.”  But the problem is that it didn't start with JPEGs of undergrad anus. It began with the show going on air. Early in April they were wearing buttplugs on air and discussing sex shops. I have difficulty believing this was a departure form their regular show format.

However, Epperson himself admitted that he had been aware at least as the beginning of 2014 that there was a behavior problem and a "lack of oversight."In many ways this is comparable to the problems that felled WXPN back in 1975. More here.  I see the blame being spread more evenly. In my opinion the most guilty party is the one who was actually charged with being responsible... not the students. Expecting 20-somethings to behave responsibly.. that's highly optimistic.What could possibly go wrong?


Thursday, July 17, 2014

Zenith Operating Guide



Do you know how to operate your turntable?  This is a manual for an early series of Zenith solid state radios, models D924, D921 and D922. I assuming this dates to the mid 1960s. Zenith's last tube consoles were phased out in 1965, so it's likely between 1965 and 1975. It's difficult to be certain.. these units aren't considered "classic" by anyone.

Record players of this era still used a high tracking weight which was a compromise between the needs of 78s and vinyl records. But it's an interesting doc filled with retro diagrams, and nwo comic sounding descriptions of FM radio and 4 speed turntables.

You can download it