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Archive for August 2008

Amateur Radio Beginnings

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We feel that the greatest objection against this bill is that if it is passed it will stifle the ambition and great inventive genius of American boys.  We boys of today are the citizens of tomorrow.  We have, many of us, already chosen wireless as our line of work.  There are vast possibilities, great discoveries, and marvelous inventions yet to be revealed in the study of radio communications.  We boys want a try at the grave rewards that are to come to the successful experimenter and inventors and these lines.  Wireless is not mere play for us boys as some seem to think.  We love the work, hence the name and amateur; but it is always the amateur or lower of a line of work who produces results.”
–  1912 – Amateur Stokes regarding Senate Bill 6412

The Discovery

James Clerk Maxwell in 1867 speculated that “electromagnetic undulations permeated the Universe”.  Maxwell gave definition to this by the famous Maxwell’s equations.  Up until the point of Maxwell scientists always had some sort of physical model to explain the outcome of an experiment.  This is the case with Michael Faraday, a contemporary of Maxwell, who explained magnetic lines of force using the physical analogy of hydraulics.  The point being that science almost always presented a physical model to explain some experimental observable outcome.

The Aether

Not so with Maxwell.  There were Maxwell’s equations describing the propagation of electromagnetic radiation but no physical model of how this worked.  And so, in the paradigm of the day, folks gave it one.  Using the analogy of sound transmitted through air there must be a medium though which EM (Electromagnetic Radiation) travels through to get from point A to point B.  Such was born the aether.

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Written by frrl

August 29, 2008 at 12:24 am

General Electric Research in RF circa. 1934

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“Remarkable short-wave apparatus, developed in the Research Laboratory of the General Electric Co., induces heating effect in the body when it is brought under the influence of 21 to 30 meter waves. 

Frequency of waves used varies from 10,000,000 to 14,000,000 cycles per second.  Brain action accelerated by short waves, research shows.  Tomorrow, we may use short waves to keep us warm instead of a furnace.”

GE Research 1934

Innovation – RF Furnaces for individuals or entire rooms

Back in 1934 GE Research Labs found an interesting effect.  If you expose a human body to RF at frequencies of 10-14 Mhz at a power level of a few Kilowatts you get a heating effect.

The idea was that this could possibly be a replacement for traditional furnaces.  You would place an individual between two metal plates, turn up the juice (RF), and the person would feel warm without warming the surrounding air – as would be required by a traditional coal or wood-burning furnace.

Provided below is an illustration of how this would work for a single individual and another illustration of how this could be implemented for a small room.

It’s amazing the origin of certain ideas – plus the danger of what is unknown at the time.

Click on any image for full size in new browser window.

Click on any image for full size in new browser window.

Written by frrl

August 28, 2008 at 1:04 am

Product Review: Yaesu FT-7800R

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Review of the Yaesu FT-7800R

The FT-7800R is a dual band 2m/440Mhz mobile radio. We won’t bore you with all the technical details. You can check the brochure yourself in the collateral files and images associated with this review.

This review will focus primarily on what is unique to this radio. The uniqueness of this radio and the price are the reasons we purchased it. The street price for the FT-7800R at the time of this writing is $265 from Amateur Electronic Supply.

Due to the wide receive range this radio is a good choice if you want to use this for traditional ham radio use (TX/RX) and if you like to listen to conventional analog transmission of  public safety, business, and anyone else licensed to use the frequencies within the RX range of this radio.

Overview

The FT-7800R has 1,000 alpha memory channels, 20 memory banks, 50 band/scan edges, and a search and store feature. This is more storage and scan capability than any 2m/70cm mobile ham transceiver on the market at the time of this writing. The FT-7800R also has a set of 5 hyper memories that can store 5 different real-time radio configurations. The Hyper-memories are hard to explain. We’ll will leave that until later. Unique to this radio, and not even available in scanners, or most ham radios, is that the memory bank size is configurable and any memory can exist in any number of banks without wasting another memory location. Be reminded that the RX frequency range is 108Mhz-520Mhz, and 700Mhz-1Ghz. There is a lot of listening to be done here. More detail on each of these features is discussed below.

One Thousand (1,000) Memory Channels

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Written by frrl

August 27, 2008 at 6:06 pm

The Wave Bubble – Protecting your personal space from RF Intrusion

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The Wave Bubble

“The new device I designed, named Wave Bubble, is intended to defend the user’s personal space from unwanted wireless communication by creating a personal “cold spot” bubble where RF devices such as those mentioned do not function.”

Social Defense Mechanisms:
Tools for Reclaiming our Personal Space
Limor Fried

Meet one of the next generation of Electrical Engineers at MIT Computing Culture Group – Limor

Limor is after a Bachelor of Science in Electrical Engineering and Master of Engineering of Electrical Engineering and Computer Science at MIT.

MIT has long been known for the innovation coming from the Media Lab.  So what is the relation between the MIT Media Lab and the Computing Culture Group?

The Media Lab focuses on pioneering advances in media and technology, often with the aim of improving human-machine interaction. Much of this work has been in new sensor designs, innovative interfaces, and unconventional integrations of existing technologies. While the Computing Culture group contributes to this body of work, its main focus is to investigate “how artists can refigure technology to address the full range of human experiences,” primarily from a social and cultural perspective

The Computing Culture Group at MIT…

The charter for the Computing Culture Group at MIT includes the question “What do technologists miss?” The research I have engaged takes this question and extends it to ask “What do people want technologists to develop?” Many engineers aim to design a technology (or sensor design, or interface) and then try to create an application for that technology, effectively building an answer and then inventing a need. In contrast, my research aims to identify a lived, experienced human need, and then determine how technology can address that need. Out of the “full range of human experiences,” I chose to focus on human-machine experiences and, in particular, our dislike of certain common electronic devices.

What has Limor frosted is other peoples cell phone conversations invading personal space. So what better than to select a solution for this with a thesis.

You can take a look at the attached thesis which describes the Wave Bubble.    Why the Wave Bubble?

Since we cannot depend on others to respect our personal space, I have decided to instead focus on how we can defend it ourselves, using special electronic devices specifically designed to combat wireless communication technologies and televisions. Having defined the problem, I set out to design two “counter-technologies…

Attached below is a thesis submitted for partial fulfillment of a Bachelor of Science in Electrical Engineering and Master of Engineering of Electrical Engineering and Computer Science.

Take a read a decide for yourself.  Do you have a right to protect your personal space from RF intrustion using the Wave Bubble? 

Social Defense Mechanisms:Tools for Reclaiming our Personal Space

 Beware of the Wave Bubble

These images are taken from the Thesis.  Maybe a new danger at coffee shops are people wearing Wave Bubbles.  Perhaps this is Linor herself demonstrating the Wave Bubble.  Watch her in the fourth image in the sequence.  The wearable Wave Bubble device is on her coat.

Written by frrl

August 25, 2008 at 12:05 am

Collecting Heathkit Models SB-101,102 & HW-100,101

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Going Vintage with Heathkit

Article Update: 27 Sept 2008 Added a couple of resources.  There is an excellent web site by k5bcq on Heathkit repair of many models.  We also found an interesting article “Hot Water for the K2” by k1rfd on how  to leverage the final power anp of the Heeathkit HW-101 (or really any of the SB/HW tube Heathkits) as the final drive for the Elecraft K2 – or any exciter source.  References to both of these articles can be found in the Resouces section near the end of this article.

We made this pitch before and we will make it again.  At the time of this writing a new mid-class HF radio costs about $1,000 to $1,500.  So for that amount of money you would purchase 5 older vintage HF radios and have 5 times the fun.  So why not go “Vintage”.

Going Vintage

A pre-condition for “going vintage” is to have some appreciation for the history of Ham Radio.  If you don’t know anything about the history of Ham Radio maybe this is your chance to learn something about this history of your hobby – or “service” if you prefer that way of speaking.

If you always wanted to know “what’s in the black box” of Radio then this is an opportunity to find out.  If you find yourself as an “appliance operator” – spinning knobs, pressing buttons, and flipping switches into some back box of unknown technology then “going Vintage” can open that box for you and show you what is inside the black box and what makes a Ham Radio transmitter really work at the electronics level.

Heath

If you want to “go vintage” and incur the collateral damage of learning about the history of radio and what’s in the black box of magical parts then Heatkit radios might be a good way to start.

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Written by frrl

August 7, 2008 at 4:55 am

Product Review – The Ultra 1000VA/600 Watt Time Machine

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Review of the Ultra 1000VA 600 Watt UPS and Time Machine

“You can fool some of the people all of the time, and all of the people some of the time, but you can not fool all of the people all of the time.” — Abraham Lincoln, (attributed) 16th president of US (1809 – 1865)

Caveat emptor – “Let the buyer beware”.

We call ”em like we see ”em. And we have to admit that over here at frrl dot net Southern Command we got fooled. We got slickered. It was due to an issue of trust. We placed our trust in some folks and they let us down. We were taken in, snookered, made fools of – the joke is on us. It’s our fault. We didn”t do the research. We saw something that looked good. But looks can be deceiving.

The Bait

So when we saw the Ultra 1000VA 600Watt UPS at TigerDirect.com for $79 we thought about the hundreds of dollars we lost when we got hit with a power surge during a storm. We thought about the data we lost when our servers got hit with a power outage. If we had the UPS our servers would be safe, our equipment protected from surges, and the router and wireless access point would provide our laptop internet access for the duration of a power outage.

So, the outside of the box for the Ultra 1000 UPS says 60 minutes of backup time for a average PC with monitor. We run our servers with a single monitor and KVM switch. The monitor is usually off and so all we have is a couple of servers and networking gear. 60 minutes – more than enough time for an orderly automatic shutdown of the servers and the network gear can continue to run. We have to thank the marketing people at Ultra for that valuable information encouraging our decision to make the purchase on the spot.

Making the kill

So, with $79 burring a hole in our pocket we made the purchase of the Ultra 1000VA 600 Watt UPS.

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Written by frrl

August 5, 2008 at 5:14 pm

50 MB of Penguin Power – PC Emulator with Embedded Linux

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DSL – Damn Small Linux

By now you have probably heard about Linux. Maybe you wanted to try it out and see what it was all about. Then you found out that to install Linux you had to create a new partition on your hard disk, or buy a new hard disk, make a dual boot system, or otherwise disturb your beautiful MS Windows operating system. Then, if you got it installed how would you get if off your system when you were done playing with it? How would you get rid of the dual boot software – grub or lilo – and get the Microsoft boot blocks back on your hard disk?

Well heck, where there is a will there is a way.

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Written by frrl

August 4, 2008 at 8:10 pm

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