The other day I went looking for an old issue of the once-free publication WorldRadio Online, but had trouble finding all the issues in a single repository. I decided to make myself one once I found all the files. So here it is: www.n5dux.com/ham/pubs

WorldRadio used to be a very low key, cheap publication about amateur radio. The kits and homebrew articles were worth a look. WorldRadio had a small following but when the much larger CQ magazine offered to buy-out WorldRadio, the owners of WorldRadio gave in. CQ has far more advertising dollars to support their publications (CQ, CQ-VHF and PopComm) - for them, it's a business wrapped around a hobby. WorldRadio was more of a hobby wrapped around a hobby.

So CQ Magazine bought the small WorldRadio, moved their "lifetime subscription" members to a one or two year CQ magazine subscription (crummy deal) and made WorldRadio into a free, online-only publication titled WorldRadio Online. (A move that jilted many of the older, not-quite-so-tech-savvy readership.) Many of the longtime readers said it was the end of WorldRadio, some said it was the start of online publications for ham radio. Both were right. WorldRadio Online was a great monthly treat because it was free. The transition to online was made easier in that the reader wasn't having to pay for it. The content got watered down somewhat as CQ wasn't making much money on the project, but you get what you pay for: no complaints. Still, longtime readers still said the end was near for WorldRadio. In October 2011, they were proven more correct. WorldRadio Online became a paid-for, online-only publication. The once-free PDFs were taken down and any new content would have to be paid for. I'm unaware of any widespread fanbase of the now online-only paid publication which can only mean it's a matter of time before the publisher pulls the plug on the project altogether.

Also succumbing to similar commercial/financial pressures is the European publication HamMag. A grass-roots, free, online publication that also failed to secure enough advertising dollars to make it worthwhile. I've archived them as well.

Finally, a publication that petered out well before the others is 73 Magazine. With 43 years in print, 73 Magazine closed shop in 2003. The 43 years of issues were scanned as PDFs and made available for the ham community. An archive of that many PDFs is sizable (too big for me to justify hosting locally), so I'll just direct you to the 73 Magazine repository at archive.org.

I recently came across a schematic that showed how to build an oscillator using the NAND gates inside a 7400 chip. After poking around online, looking for the 7400 (and not some variant) I learned the LeTourneau University College of Engineering has a parts supply closet with a whole stash of them for 5¢ each. (I've known about the parts closet for quite a number of years, but only recently discovered a tall filing cabinet full of most commonly used ICs. (No NE602 or 612s, I'm afraid, but that's another post for another time.)

So, with my 7400 in hand, I was able to breadboard an oscillator using the "colorburst" crystal at 3.579 MHz. The oscillator emits a square wave at the fundamental frequency, so harmonics abound. In fact, just through playing around with another receiver, the 3rd harmonic at ~28.632 MHz is considerably stronger than the others that fall in the ham bands. (All higher harmonics are just above the ham bands, though I may be able to pull them back down with a variable capacitor in series with the crystal.) I need to do some range testing on this to see just how far I can get on the various bands.
My next trick is to build a bandpass filter network to dampen the harmonics down to legal levels. Then, I'll have a bona fide transmitter, though very, very low power. Perhaps a final amplifier is on the drawing board next.

I recently picked up a Propeller Board of Education from my recent trip to Parallax, Inc to teach the Teachers' Institute for the ARRL. The Propeller is Parallax's latest microcontroller platform that offers far more than the old beloved BASIC Stamp could. Digging back through my old posts, I found my initial review of the Parllax BASIC Stamp from 2006. (Little did I know that about 5 years later I'd begin teaching classes on the Stamp, visit Parallax HQ, and befriend the author of the "What's a Microcontroller" book (among other titles).)

The Propeller is a programmable multicore microcontroller that can be programmed in Assembly, Spin (an Object-Based programming language that I'm still learning), or, most recently, Standard C. The multicore design lends itself well for many, many projects, chief among them is robotics. Now your creations can take in and process loads more data at once. And with robotics, the more sensory input your bot has, the better equipped it will be to handle various tasks.

I just recently began to fully grasp the power of the little Propeller chip. Once the relative simplicity of utilizing the 8 cores available (known as "cogs"), the possibilities begin to multiply and compound one atop the other. My initial reluctance to the Propeller was the Spin language. The operators seem a bit foreign compared to the C-style languages I've been comfortable with for so long. The various code sections also seemed confusing initially. After reading through the tutorials posted on the learn.parallax.com website, I was up and running in a relatively short amount of time. I also took advantage of the Propeller Manual (pdf) and Programming the Propeller with Spin (pdf). While both offer great starting points, be sure to reference the learn.parallax.com site first - the Programming the Propeller text has its weaknesses. All in all, Spin is a relatively easy language to pick up if you already have some programming under your belt.

Another great aspect of Spin is the ability to utilize Spin objects (or libraries) from the Propeller Object Exchange. Modern microcontroller programming is all about code reuse and sharing: find the code you need that someone else (hopefully) did a good job writing, plug it into your codebase and immediately make use of it.

Far more exciting still is the recent ability to program the Propeller in C. While Spin is great, having to learn another language can be a real turn-off to would be programmers of such a chip. The Arduino is neat in that regard and I must admit I've been smitten with the Arduino since beginning its use. However, the Arduino can only do so much. It is limited by the fact that it's a single core design. For the past few years, users have sacrificed power and utility in order to gain ease of use - no more. With the upcoming release of the stamplib C library, there's little reason to not opt for the Propeller.

Oh, what's that? Price is a big selling point? The Arduino typically sells for $30, the Propeller Quickstart sells for $25 ($50 if you want it from Radio Shack today and can't wait a few days for UPS).
The PropBOE is far more extensible, though. It currently has a high price tag but comes with a lot to offer. VGA output, 1/8" audio out, microphone for audio in, micro SD for storage, ADC and DAC, a mount for an XBee wireless module as well as the ever-present bank of LEDs for feedback - did I mention is has tie points for 6 servos? Not bad for $130. If that seems a bit too steep and you doubt you'd use all the features, a stripped down PropBOE is rumored to be in the works for a target price of $50.

Since long long ago the military has used maps and graphic symbols to plan and implement combat plans. So to plan a mission, you need a MGRS topographic map, a blow up of the same map covering your Objective, and enough laminate overlays to fill a small car. I love arts and crafts just like the next guy, but is the sales guy at the mall gets a touchscreen tablet, why cant we get planning software. My list of needs: -a topographic version of Google Earth with Military Grid ref System -variable zoom and contour intervals -ability to capture snapshot the desired map -several tabbed 'layers' that I can toggle on and stack as needed -simple drawing tools -a tactical symbol database, one that recognizes the symbol I'm trying to fat finger and inserts it for me. That is all.

For anyone online you've no doubt heard that social media is defined by sites like Reddit, Facebook and Twitter. A lot of people talk about Twitter, but a vast majority of people don't know how to use Twitter. I must admit that I've had an account for years but wrote it off because it seemed so limited. The power of Twitter is not found in the brevity of the "tweets" (posts that users make on Twitter), but in the ability to monitor tweets of others.

Flow of news
In the traditional model of news aggregation, you would turn on the TV or radio, open a newspaper or seek a sole source of information. That organization would have already done the leg work of finding news, picking out what they thought the majority of their viewers/listeners/readers would find appealing and put that news out there. With the introduction of "social media", suddenly people can discern for themselves what is important. The early days of Digg brought this idea to reality and reddit took over where Digg left off. The users were now in control of the information, not the producer, publisher or editor. I'm not saying that Twitter affords this ability, but it allows you to search for items that have been flagged with certain key terms. In Twitter parlance, this flag is known as a hashtag. Until I understood hashtags, I didn't "get" Twitter - now I do.

#Hashtags - The key to Twitter
Hashtags allow you to share information that you tweet with others within a community of individuals that are, themselves, looking for information relevant to a subject. The same way that you search for things with a search engine through key words, you can also hunt for tweets with a hashtag.
I deal a lot with Education Technology, so when I'm looking for news, links and information related to Education Technology, I'll look at the Twitter hashtag #edtech. If I want to look at tweets dealing with education in general, I'll look at #edu. If I want to find information about space, I would look for the #space hashtag. Robotics has #robotics All of the results for each of these tags will show content that individuals shared on Twitter and then tagged with the relevant hashtags (and you can use multiple hashtags on your tweets as you may see some users doing). Hashtags are denoted with the # sign (hence the name).

Tweeting @users
If, for example, I wanted to Tweet at or to a person in particular, I would use the @ symbol, followed by their Twitter username. This allows the user you are referencing to see the tweet made "at" them so they can respond or pass along the information. I don't use this feature very often, but as your use of Twitter grows, so will the number of times you'll find this feature handy. For example, if you wanted to tweet at me, you would post something like "@MrGoberTX Thanks for the Twitter intro on neodux.com".

Twitter for organizations
So what's the big deal with businesses and organizations using Twitter? Contrary to Facebook, Twitter is a "one way street". Facebook is like a two way street, it allows you to communicate back and forth. I can post something on Facebook that my organization is doing, and you can "Like" it or comment on it. Until I go to moderate those comments (they may not all be positive or socially acceptable), everyone will see these comments from people they don't know. Some users may be offended by the content of your Facebook comment, but it will appear on the page until I take the time to login and take it off. That two way street can be a liability that I must babysit vigilantly.
Twitter on the other hand is a one way flow of information - similar to a press release. This is what I'm doing, here's what you need to know, thank you, have a nice day. If someone were to want to leave an offensive remark, that remark won't show up on my page. This protects the people that view my page. The user with bad intention's best hope is to attach a relevant hashtag and hope some user is looking for information via that hashtag and not directly from my organization's page. This one way flow of information is a great way to share what you're doing with the public without opening yourself up to others' comments.
This difference in usage is what makes Twitter ideal for large, litigation prone entities like companies, school districts, etc. You don't have time to babysit your account to clean out all the nefarious comments, nor should you be expected to respond to each user - that one way flow of information is just what you need.

Panning for gold
Once people get on Twitter and start hunting for hashtags that are useful, they quickly realize the vast amount of information flowing through Twitter. How can they make sense of it all?! I liken Twitter to standing next to a roaring river, panning for gold. You can't possibly glean every little flake of gold from the river, you've got to accept that. Find what little nuggets you can and move on. Come back later when you need to hunt for more. Over time you'll develop a sense of what hashtags are worthwhile and which ones stay relatively dormant, just as the gold prospectors knew which parts of the river were worth working and staking a claim on.
As you get a better feel for Twitter, you'll begin to see which hashtags belong to your interests. Then, when you're ready to share something with the world at large, you'll know how to "tag" your tweets in order to garner the audience you seek. At that point you'll finally "get" Twitter.

On usernames
It's worth pointing out that your Twitter username can serve as your sole identity to some Twitter users. You will find certain users on Twitter that you have no connection with other than a shared interest in a particular topic. When selecting a username it's good practice to make it something easy to relay to others (nothing too cryptic) and one that you think represents you well. Several users will attach a small picture of themselves to their Twitter profile so others can put a face with their name.

So where do I start?!
First things first, you don't have to have a Twitter account to use Twitter. You only need an account when you're ready to tweet something. The best place to start is to find a notable figure or brand in the subject you want to hunt for and "follow" them (just read their Twitter feed). You'll begin to notice the hashtags they are using for your interests and then you can begin to scour those hashtag feeds for others to follow or other, related hashtags.

Resources
To show you how many hashtags there are just for educators, I have a list of hashtags over at MrGober.com: http://www.mrgober.com/hashtags
If that's how many teachers have, you can imagine how many there are for news stories, events, pop culture, hobbies and brands. It's just a matter of finding them! My personal favorites are #edtech #hamradio #news #edu #arduino .
If you're looking for me on Twitter, my username is @MrGoberTX.