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Thursday, March 25, 2010
Saturday, March 20, 2010
Antennas That Bend, Stretch, and Twist
Via US News & World Report
Antennas That Bend, Stretch and Twist
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Antennas That Bend, Stretch and Twist
Researchers have created a new type of antenna made of liquid metal that can bend, stretch and twist, then return to its original shape, an advance in technology that could lead to new uses where resiliency is especially important--in the military, for example, or for rugged outdoor activities.
snip...
The scientists made the antennas by injecting an alloy made of the metals gallium and indium, which remains in liquid form at room temperature, into very small hollow channels the width of a human hair. They used elastic silicone channels to hold their alloy, and then fashioned wire-like antennas out of the material. The channels, which resemble straws that are open at both ends, can be manipulated into a variety of shapes.
Once the alloy has filled the channel, the surface of the alloy oxidizes, creating a “skin” that holds the alloy in place, while allowing it to retain its liquid properties. "Because the alloy remains a liquid, it takes on the mechanical properties of the material encasing it,” Dickey said.
snip...
Another discovery: "If you cut this device just through the metal--not all the way through--it comes back together," Dickey said. "You can partially damage it, and it will self-heal."
Since the frequency of an antenna is determined by its shape, "you can tune these antennas by stretching them," Dickey said.
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Cool Site of the Day
Check out this comprehensive photo gallery of some of the most coveted boomboxes of yesteryear. Covers eras, so you can track the changing styles and ebb and flow of popularity. The photo below is of the Panasonic RX-5350, which I would love to get my hands on!
Pocket Calculator's Online Vintage Boombox Museum
Pocket Calculator's Online Vintage Boombox Museum
Panasonic RX-5350
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FCC Chairman Julius Genachowski - Broadband Bill - PBS Newshour 3/15
Via PBS Newshour
Video on this link.
Via Television Broadcast Mag
FCC Proposes Reallocating 40 Percent of Broadcast Spectrum
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Video on this link.
Via Television Broadcast Mag
FCC Proposes Reallocating 40 Percent of Broadcast Spectrum
WASHINGTON: Broadcasters stand to lose 40 percent of their spectrum under the FCC’s new National Broadband Plan, due on Capitol Hill tomorrow. The plan was released in Washington today; details emerged in several reports. The goal of the plan is to bring 100 Mbps broadband access to 100 million American homes in 10 years, nearly doubling the current reach of high-speed Internet access.
It calls for making 500 MHz of spectrum available in 10 years, and 300 MHz available within the next five years, for both licensed and unlicensed use. Of that, 120 MHz is to come from television broadcasters, who now occupy roughly 300 MHz.
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Cool Site of the Day
Register and participate. Upload that vintage, esoteric, or otherwise A/V manual that you have laying about and help yourself to the mountain of manuals. Fantastic site!
The HiFi Engine
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The HiFi Engine
Looking for a manual for your hi-fi equipment?
The HiFi Engine has thousands of owners manuals, service manuals, schematics and product catalogues covering amplifiers, pre-amps, power amps, tuners, tape decks, cd players etc.
The files are free to download, all that we ask is they are not redistributed for financial gain.
Thanks to the many visitors who have scanned documents and donated images to the gallery.
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Sencore SA 1454 and SLM 1456 TV RF Digital Spectrum Analyzers
The Sencore SA1454 and SLM1456 are popular amongst the prosumers. The SLM1483 lacks graphing capability so is more of a signal analyzer. Here is some information from Sencore to help you decide which one is right for you....and to understand the information that these units provide and how it can help you.
Sencore's Good - Better - Best TV RF Signal Analyzers
How to read your spectrum analyzer...
Analyzing TV RF Signals
ATSC, NTSC, UHF, VHF, FM, TV, RF, 8VSB, Digital Television, Field Strength Meter
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Sencore's Good - Better - Best TV RF Signal Analyzers
How to read your spectrum analyzer...
Analyzing TV RF Signals
ATSC, NTSC, UHF, VHF, FM, TV, RF, 8VSB, Digital Television, Field Strength Meter
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Wednesday, March 17, 2010
C-SPAN Posts Its Complete Archives Online
CSPAN Video Library
Via Television Broadcast
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Introducing the C‑SPAN Video Library. 160,000 hours of political events covered by the C‑SPAN Networks since 1987, with more added each day. Search it. Watch it. Clip it. Share it – all at no charge. Our Video Library lets you follow Washington your way – another public service created by America’s cable television companies.
Via Television Broadcast
WASHINGTON: The Cable-Satellite Public Affairs Network has now made their entire archive available on the Web site.
C-SPAN has now loaded up 160,000 hours of video, going back to 1987, on its Web site, with widgets for sharing on Facebook and Twitter. The database is now available online; a formal announcement is due on Wednesday.
The archives continues to record all three C-SPAN networks nonstop, indexing them and placing them in the database. Programs are indexed by subject, speaker names, titles, affiliations, sponsors, committees, categories, formats, policy groups, keywords and location. The congressional sessions and committee hearings are indexed by person with full-text.
Not all the resources are free of charge. All programs since 1993 are digital and can be viewed online for free. Duplicate copies of earlier programs can be obtained and used for education, research, review or home viewing purposes for a fee. Also, some programs are not copyright cleared for sale.
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Documentary - The War of the World - Niall Ferguson
Interesting slightly different perspective on the epic violence of the 20th Century. Worldwide ethnic and racial conflict...and the rise of the Second and Third World.
The War of the World - YouTube Part 1 - 30
This is one of the best documentaries of the 20th Century. See here and here, also.
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The War of the World - YouTube Part 1 - 30
This is one of the best documentaries of the 20th Century. See here and here, also.
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EV's Best Recommended TV Antenna Rotors
Here are my favorite antenna rotators from yesteryear.
Norm's Rotor Service has many rotors for sale refurbed and new. They bought the remaining stock of Alliance rotor parts and units.
Hy-Gain continues to make many of the CDE model rotors. They bought up CDE when they went defunct in the 1990s.
All of these rotors listed with the exception of the Yaseu, which is made in Japan, are Made in USA.
Alliance
U-100
U-110
The U-100 and U-110 are more or less identical units. Made in USA, they are well built, and feature worm gear drives. 4 Wires. The worm gear drives are desireable in these units, they are more precise and stout than all the others here. However these units have two peculiarities. 1, they are only adjustable to every 5 degrees or so, and 2, the controller boxes make an annoying clunk-clunk sound as they turn. Fairly commonly found on eBay, and available new from Norm's Rotor Service.
Here is a video which demonstrates...
T-45
The Alliance T-45 is a manual control unit, with a sturdy rocker bar, used to rotate the antenna. Its not as nice for television use, because 1 revolution on most all rotors is once per minute. The automatic dials are preferable. It is 5 wire and has worm gears like the U-100 and U-110 above. The rocker bar is nice, as it allows for precise control for zeroing in on a signal. Unlike the U-100 and U-110 above, this unit is infinitely adjustable. Uncommon on eBay.
CDE
AR-22
AR-33
AR-40
This is the classic TV antenna rotor series from Cornell Dubilier Electronics. The AR-40 is still in production by Hy-Gain. High quality rotors. One interesting aspect of these, is that they are not offset rotors...the masts, above and below come into them in a straight line. 5 wires. Fairly common on eBay.
TR-44
CD-44
CD-45
These are a bit more stout than the AR series, which means they can take more weight and wind loading. These are 8 wire units. Fairly common on eBay.
Channel Master
9515 HD (Heavy Duty)
These are very rare. A sturdier version of the 9510A below.
Colorotor 9510A
The CM Colorotor 9510A is made in USA. The RadioShack/Archer rotors below are the same units, under different branding. 3 wire. These are preferable to the new Chinese made Channel Master rotors (which are seemingly branded by everywhere). The older style controller boxes are a bit more hefty and solidly built. You can also use these with the newer 9537 remote controlled controller boxes that ship with some of the newer Chinese made models. Pretty commonly found new old stock on eBay.
Gemini
Orbit 360
Also known as the OR-360, and Gemini is affiliated with Philips. These were made in the US and sold in Walmart in the 1990s and early 2000s. Discontinued now, you can still find them used and new old stock on eBay sometimes. Pretty good little units, though not as stout as the CDE and Alliance rotors recommended here. 5 wire connection. I use this personally. Uncommon on eBay.
Radio Shack & Archer
Archerotor
1225A
1225B
These are clones of the Channel Master 9510A, see above for details. Pretty commonly found new old stock on eBay. 3 wire.
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The Alliance HD-73 and TailTwister TX2*, Yaseu G450A, CDE Ham M, II, III, IV, and V series are good as well, but are a bit more expensive generally, and are overkill for television antenna weight and size.
18 gauge solid copper core wire should be used for runs over 100 ft, 20 gauge is fine for under 100 feet.
Thrust bearings are available to allow the use of taller masts with these rotors. There are 2 types.
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