Check out my full length article on “Fixing a broken Diamond Antenna (poorly)” here: http://www.n5ebw.com/fixing-a-broken-diamond-antenna-poorly/

Since Ike has me stuck in the house today, it gives me a chance to get to some badly neglected projects. I ripped these two circuit boards out of a couple of dead UPS (Uninteruptable Power Supply) units that my friend Barry gave me to salvage. The batteries are currently being used in a fox hunting transmitter unit. Here’s the before shot before I started doing the recovery:

(Click for full size image)

You may look at this and think it is total junk. In our modern day ecosystem, the techno-trash our species has produced is causing an overwhelming impact on our landfills, and everything downstream of them. The toxic lead runoff from a circuit board can seep into our water supplies and can have negative consequences on many other things. No, I have not become a hippy, and I’m not encouraging you to go lead a life of poverty just to give back to the environment. What I am saying is, please be careful about what you throw away. If at all possible, recycle it. Be mindful of where that trash is going to go.

That being said, if you are still here, I will continue.

One of my hobbies to keep all of that techno-waste from hitting the landfill is to recover parts that may be of use to future projects of mine. I’ve been stockpiling the circuit boards in boxes, with the intent of taking them to a recycler to reclaim the hazardous materials on them. If anyone knows of such a place in Dallas, let me know. Here is what I reclaimed in about an hour off of the above boards:

(Click for full size image)

A great bag of loot from this one! About 8 LED’s (light emitting diode), a few LM317 voltage regulators, some N-Channel MOSFET(Metal Oxide Semiconductor Field Effect Transistor) power transistors (60V 10A, AWESOME!), a few 30 amp fuses, transformers, bridge rectifiers, 5 watt resistors, and so on. These parts would probably be about 25 to 30 dollars total if you bought them new. I know your time is worth something, and maybe I came out a little under in that regard. The way I see it though, I am keeping my junk box stocked up for future projects, and keeping a little bit of volume out of the landfill. If it’s your thing to help the environment and have a little fun in the process, this may be something you want to do as well.

This also reminds me of the scrounging I did when I was in school for things. It’s no secret that a lot of students aren’t rich, and a lot of times, this was the only way I could afford the things I needed for projects!

Normally, I don’t write content based on things written in other blogs, but today I couldn’t help myself. Make Magazine featured a post on their blog about some online electronics tutorials from the University of Wisconsin. This is GREAT for all of the hobbyists out there who need something to reference without going to take classes, or getting expensive books. Did I mention they were interactive? That’s right, interactive tutorials on a variety of subjects including everything you ever wanted to know about AC and DC electricity. What a HUGE reference. There are also special sections for sensors, robotics, digital and solid state electronics. Recently, sections on non-electronic subjects were added as well, to include hydraulics and pneumatics; something I know some of my readers are interested in!

If this is something that seems like it is up your alley, or, you just want to validate that I haven’t lost my mind in the quest to bring you quality content, check it out: http://electronics.wisc-online.com/

I occasionally get copied on some of the “weather happenings” from the east coast, courtesy of my friend, Steve Crow, KG4PEQ. Today, I was reading through my email and he had copied me on an email he sent out to the SKYWARN spotters who are involved with the Wakefield National Weather Service office in Virginia. In this email, Steve was complimenting the ham radio operators who serve the SKYWARN program on the great job that they did yesterday when severe weather rolled through the region. He will probably deny this, but he is single handedly responsible for reorganizing, and resurrecting the once dead SKYWARN program in Wakefield, after being designated the SKYWARN coordinator (this was LONG overdue if you ask me). A tremendous amount of coordination and hand holding, along with some first hand frustration I observed on his part, and then, like magic, the system was back up and running again. Not only are they offering Basic and Advanced spotter training more often now, but there is a mechanism for traning new net control operators as well.

Okay, so maybe this post is a little less about SKYWARN and you, and more about Steve saving the day, but I can fix that, because it’s my blog. So there.

When severe weather is in the forecast, the local National Weather Service office may request “Spotter Activation” (you may have heard that on your scanner, even if you are not a ham). The NWS needs first hand observers to add to the validity of their forecasting, because you can’t surmise everything from RADAR, and charts, etc. This is especially crucial when lives or property loss are at stake. Spotters are there to give accurate wind, hail, rain, etc etc etc, weather reports of a first hand nature based on certain criteria. They are usually the one’s who know when the tornado is on the ground before anyone else, among LOTS of other things. There aren’t many tornadoes in Virginia compared to what we get here in Texas, but they have their fair share of severe weather as well. I should know, I grew up there. SKYWARN isn’t available in only Virginia and Texas, though. Wherever there is a NWS office, SKYWARN isn’t far away. Most spotters are Ham Radio operators and are well acquainted with net control procedures as well as having a general to elevated interest in meteorology.

Interested in becoming a spotter? No prerequisites are required; not even an amateur radio license, although it makes spotting a lot easier. Contact your local NWS office, or, you can always contact Steve or myself. We’d be happy to point you in the right direction and welcome you aboard!

More information:

WakeField WX4AKQ

NWS Sterling, Va. SKYWARN

Dallas/Ft. Worth SKYWARN

Wikipedia

This past May I had the fortunate experience of riding with Kent Britain, WA5VJB to the Dayton Hamvention in Ohio (he may tell you otherwise). Among other things, Kent is an exceptional antenna designer, with projects on his resume that include antennas that were conceived to reside in the second stomach of a cow (Try to figure out THAT dielectric constant!). You may have read his articles in CQ and CQ VHF magazines. He kind of knows a thing or two. I crap you negative.

Anyway, what I came to tell you about are a unique design approach Kent has for low cost antennas. Before Dayton, a group that I do some hobby work with was looking for a directional WiFi antenna to interface with a Linksys WRT-54G router that was powered by PoE (power over ethernet) and mounted to the side of a piece of antenna mast. The project was created out of necessity to reach a ranger station that was just out of reach for our stock omnidirectional antennas. We ordered some of these from Kent:

What you see are two high gain antennas for 2.4 GHz designed onto printed circuit boards! Here are the datasheets:

Quad Patch antenna datasheet (sadly, this antenna has been discontinued)

Yagi antenna datasheet

We ended up using the Quad Patch for a few reasons. First, we could easily mount it to the side of the weatherproof telecom box we strapped to the tower (the router was mounted inside). The polarization needed by the Yagi to work did not line up with the tower leg we were using. Second, according to the datasheet, ir provides 11 dBi gain, which, in retrospect, was overkill, but who cares.
They work GREAT and do a lot better than a “cantenna”, (Which, if you model it with antenna software, has some serious flaws).

So, if you are on a budget, or just want a great antenna for your project, I highly recommend you check out Kent’s website over at http://www.wa5vjb.com. More on our WiFi project in a later article…..for now, go build your own!

Tonight I was watching videos of different lathe operations, thinking of when I would finally get to use my lathe. I happened upon two terms I had not heard in a long time: Curie point [temperature], and Austinizing. Not the usual drivel you find on Youtube, I know, but onward we go…..

Quickly, Curie point is the temperature at which magnetic material loses it’s magnetic properties.

Austenizing is merely a process where the metal is heated to a solid solution and cooled rapidly in either oil, water (or air, as it were). This makes the steel hard, but brittle. To overcome the brittle properties of the metal, it is then usually tempered at a very controlled (hot) temperature for a controlled time to make it a little more ductile (bendable, less likely to fracture). Usually, I just hear “heat treated“.

Anyway, the actual usage of the two terms was because of confusion between them. One commenter was using the terms interchangeably. This is often the case, because a lot of steel alloys have a very close Curie point and Austenite transformation. In some cases, this is not so. M2 tool grade steel, for instance, (the stuff they make wrenches out of) is one such example.

Not really a big to do about anything, but it brought up some interesting subjects that I used to know a lot more about (as you can see, I barely regurgitated the definitions), and must put on my to do list to relearn.

Good stuff!

For some reason, when they built a lot of the buildings in the early to mid 90’s, they decided it would be a good idea to wire the entire building with Fiber Optics to every desktop, thinking technology would catch up. Enter Present day: Apparently technology has caught up in every regard except for the cost efficiency of a fiber card in every PC and laptop in the building (Have you ever tried to order a laptop with a fiber optic network interface?). Fiber to Ethernet converter boxes are what a lot of I.T. shops are using to get around that nuance. There is one inherent problem: They don’t last very long. Here is a picture of the circuit boards that came out of a bunch I am in the process of salvaging:

Note the white circles and arrows. Each of these has a 25 MHz crystal oscillator running the clock. Something I have not determined is whether this is an ordinary crystal oscillator or a TCXO (Temperature Controlled Crystal Oscillator). Anyone who is not familiar with the difference between an oscillator and a TCXO need not be afraid. Crystals, by nature, are affected by temperature. The resonant frequency can change (sometimes drastically) with the addition or subtraction of heat. TCXO’s resolve this fundamental problem by providing corrections to the shift in frequency using analog sampling of the output and compensating accordingly.

The challenge with identifying it correctly is that there is virtually no data on the internet for this part, and both types of oscillators can look exactly alike! (For those interested, they are all MMD MB050HA) If anyone knows, please inform me.

Either way, these are all getting reclaimed and thrown in the junk box for a future project! 25 MHz is not ideal for any microcontroller clock, but with a little convincing I could probably turn it into something on one of the HF ham radio bands. Happy circuit bending!

A few of you have expressed displeasure in the fact that I did not have a working site for a few months now with anything meaningful on it. Well, here you are.

Still nothing meaningful…and, don’t hold your breath.

-Eric