Popular Science and Popular Mechanics on Google Book Search!

Google Book Search announced today that it was posting scans of several magazines, including Popular Science and Popular Mechanics online.

I'm excited because it means that old radio articles in these magazines are available for viewing.

Try this: Go to http://books.google.com/advanced_book_search, and enter the words "crystal", "coil", and "condenser" in the search window. Check the "Full View Only" and "Magazines" buttons. It returns a bunch of magazine articles on crystal radio sets.

Now the next trick...To bookmark the article, you don't have to save that entire godawful URL it brings up. You can trim from the end of the URL to the "&pg=PAXXX" term. The rest is just for highlighting the search text in the article and stuff.

More Satellite Page Hacking

Writing bookmarklets can become addictive. Here is one similar to the AMSAT hack for Heavens-Above. Go to the Heavens-Above amateur satellites page (once you've registered,) and then paste the following code in the Address bar:

javascript:(function(){var%20minElev=Number(prompt("Enter%20minimum%20elevation.","30"));var%20table4=document.getElementsByTagName('table')[4];var%20row=2;while(row<table4.rows.length){if(table4.rows[row].cells[5].innerText<=minElev){table4.deleteRow(row);}else{row=row+1;}}})()

Outer Banks and Radio

I just came back from a vacation to the outer banks. While we were planning, Lennie found a ham radio connection there. It turns out that the Outer Banks is where Reginald Fessenden proved the viability of AM Radio during tests he made there in 1901-1902. The photo is from the marker at Weir Point. There is another marker just over the bridge to Pea Island. We passed it, but were pretty tired from our trip to Ocracoke and didn't feel like stopping. Besides, as Lennie said, "How many Fessendens does any one person need?" More info and a photo of the other marker are in a paper by VE2VC (PDF).

I got a chance to operate QRP from the beach this trip. My station consisted of an MFJ 40-meter QRP Cub transciever, an MFJ 30-meter 9030 transciever, and a Hendricks QRP Kits SL Tuner. For most of the trip, I used a 51-foot length of copperweld tied to the wooden handrail of the walkway leading out to the deck. I had a 16-foot length of copperweld dangling down to the sand for a counterpoise. I didn't have much luck on either 40 or 30 meters. Finally, on the last day, I got out my DJ9SQ mast and set it up with a "folded vertical" fed by the SLT. The 51-foot length of copperweld became another radial. This time I had better luck on 30 meters. I just need to brush up my code. Apologies to those I assaulted with it.

Update: Another great article on Fessenden and the Outer Banks is at coastalguide.com.

Why do hams hate proprietary codecs?

Recently, WinDRM took down its downloads because it used the MELP codec by default for encoding voice. It was restored to change the default to an open-source codec. Read about it at ARRL's web site

I have heard people telling me they won't use D-Star because it uses the proprietary AMBE 2020 codec. Never mind that the rest of the protocol is free for amateurs to use.

The normal way these codecs are used is to embed them in a chip, which, when you pay for it, goes to license the intellectual property inside.

Think of it this way. DeForest vigorously defended his patents. You could use his tubes in your radio, but if you tried to copy his tube and sell it as your own, you got sued.

It gets more complicated in the WinDRM case, and the analogy gets a little frayed. WinDRM used a freely-available copy of what is normally sold by TI and other companies. Back in 1915, no one would think of making a copy of an Audion tube and giving it away, but imagine someone did. Maybe they hated Dr. DeForest. Do you think that it would go unchallenged?

TI and the other rights holders are protecting their interests. They winked at hams for a while, but no more. If they don't protect their interest in this codec, which is used by the US Department of Defense and others, they will appear to have abandoned it and will no longer be able to sell it.

Either buy the chips, license the codec (in which case you'd have to start charging for WinDRM) or come up with your own. Amateur HF digital voice is begging for an open-source codec with a similar performance. How about a homebrew transciever in QST that uses AMBE-2020 chips?

More AMSAT Website Hacking

AMSAT has a page that predicts satellite passes. My problem with it is that it lists ALL of the passes, including ones that just graze the horizon. I generally tend to avoid them.

The following bookmarklet clears out all passes from the table of results that are less than 30 degrees above the horizon. Go to the AMSAT Prediction and get a list of passes for a satellite. Then paste the following code in your browser's address window and tell it to go. It should shorten the table.

***UPDATE - An error crept in when I posted this before...I had the row variable running to row <= table5.rows.length, and it ran over the end of the table, giving errors. The version below seems to work better.

***UPDATE - Added a prompt for the minimum elevation.

javascript:(function(){var minElev=Number(prompt("Minimum Elevation","30"));var table5=document.getElementsByTagName('table')[5];var row=2;while(row<table5.rows.length){if(table5.rows[row].cells[4].innerText<minElev){table5.deleteRow(row);}else{row=row+1;}}})()

It works in IE 6 and Firefox 2.0.0.15.

Hacking AMSAT's Website

AMSAT has a nice web site, full of information on amateur radio satellites, tools for tracking them, news, etc.
My gripe with the site has to do with the page style. The background image is something called "flannel", which is a bunch of fine black stripes on a white background. For me, it is too much white. To make matters worse, on some monitors, the stripes do some sort of flickering. Not Moire lines, but flickering, probably due to some video card setting I have wrong.
Rather than impose my tastes on others, I wrote a goofy little Greasemonkey script to change the background:

// ==UserScript==
// @name BlueAmsat
// @namespace http://userscripts.org/users/57521
// @description Change the AMSAT default background to blue
// @include http://www.amsat.org/*
// ==/UserScript==
document.body.style.backgroundImage = "none";
document.body.style.background = "darkblue";

You can install it directly here

Gas Prices and Hamfests

According to Gasbuddy, prices in my area today are averaging to $3.92 per gallon. My 300C gets about 24 mpg on the highway if I can believe the computer, so that makes my 320-mile round trip to Dayton cost $52.

Last year, a gallon cost $3.27, for a cost of $44. The 300C manual says to use mid-grade, but prices tend to track.

At any rate, I am not going to miss Hamvention for $8.

Another perspective is on Eham.net.