Author: Tommy

Well, it's taken me a while to make a post about this one. It was a goal of mine after I completed the simple foxhole radio and one I set out to complete over the Christmas break. I decided since the crystal set was the simplest radio to build, what's the next step? The one-tube regenerative circuit was the answer.

Lately I've been reading quite a bit about radio history and have read about the huge leaps in receiver technology with the advent of the "audion" or vacuum tube. A lot of initial growth in radio reception is thanks to this circuit designed by Edwin Armstrong while still a junior in college in the early 1900s.

I scoured the net looking for parts (chiefly the 3S4 tubes) and kept coming back to Borden Radio Company. Rather than drop alot of money on shipping from various sources, I purchased a kit from Borden. It also happens that he doesn't live too terribly far from my parent's so I was able to meet up with the owner/operator, Lance Borden, over the Christmas holiday.

I pieced the kit together in two evenings. The first evening was spent winding the coils and mounting the hardware. The next night was spent meticulously wiring the components as outlined in the directions. (Maybe color coding the wires would have made the instructions a little clearer, but I can't complain.) The radio worked right from the get-go. It's tuned for broadcast AM reception and works like a charm. As you can see in the picture it requires quite a few batteries to power the tube, but it is 100 times louder than the crystal set and much more sensitive. I've heard stations all over the nation on this little set. This evening alone I was able to quickly tune into WWL 870 from New Orleans as well as KOA 850 out of Denver, Colorado.

The controls are finicky and not really what the casual listener would want, but the sensitivity and simplicity makes it worth the effort. Aiding reception is the clear audio produced by the old high-impedence Allied Radio headset that I purchased with the kit. The owner of Borden Radio assured me I wouldn't be disappointed with the headset as it works so much better than the old ear piece I had been using - boy was he right!

So, if you're following my steps through the old style radio setups, this is a step you definitely don't want to skip.

Another shot of the radio is here. (I tried to get a shot of the dim glow of the tubes, but the camera just wasn't able to capture the almost imperceptible light from within the tube.)

Next up: Super-regen? Super-het? FM ? (the passive FM is almost too tempting)

Special thanks to Notorious on his belated Christmas gift to me and Jennifer. He hooked us up with another board game to add to our collection: The Settlers of Catan.
It's a very fun and dynamic game. There's no set layout of the board. It consists of several hex-tiles that sit side-by-side to construct a new, somewhat random arrangement that allows for a ton of different board layouts. Each game is different, so strategy must be changed and player must be able to adapt quickly to win. The goal of the game is simple, amass 10 Victory Points which are achieved by building settlements, cities and collecting Development Cards. There are different costs associated with each. To find out more about the game, check out wikipedia or University of Catan.

We were able to play a game with myself, grimlen, notorious and araolath; grimlen won - the punk. It's a great game, a little bit of a learning curve, but it's not bad once you get the hang of it. IM me if you'd like to try out the PC version.

After the success of my last post about my simple razor-blade radio (link here), I began work on making a slinky dipole. I tried to use 2 Slinky Jr. toys which I bought at Walmart for $.88 each. It didn't work as well as I had hoped. After quite a while of the coils sitting on my desk and playing with them, it dawned on me that I could easily use the small Slinkys as the tuning coil for a simple radio. I started to do the math to find the inductance of the coils. I measured 1.5" in diameter, which gave me 4.7" in circumference. I started to count the coils to calculate the open-air coil formula that I had used before. I stopped and thought, why bother? Just try it out!

I stretched the slinky to the length of the board I used on the old razor-blade radio and tacked it down. I made the proper connections, using a diode first. (Ground went to the 3rd prong on a power outlet, the antenna wire and clip was hooked to my 20m ham radio antenna, on my roof) I started with the diode because it is far more efficient than the razor blade, which equates to louder audio in the earpiece.

Right off the bat I was able to hear shortwave broadcast stations! Wilder still was my ability to receive the signal without having the antenna clip attached! I tried various points along the coil, finding I was able to hear certain stations better at different points on the coil. As before, I was able to hear local AM broadcast stations just fine, and various strong shortwave stations with a "shorter tap".
After listening with the diode for a few minutes, once again amazed at the simplicity of the setup, I switched to the razor blade setup I had used in the past and was just able to pull out the same local broadcast signal from before. The key to using the razor blade/saftey pin is using a pencil lead wrapped soldered to the pin. Then ever-so-lightly "fishing" for the sweet spot on the razor that allows the signal to pass. It's also important to note you'll need to be in a fairly quiet environment to hear the signal, but if you listen - it's there.

So now you have no excuse but to find a crystal set earpiece, the coil has been made for you and it'll cost you under a dollar to buy. Alligator clips help, but as you can see, are not 100% necessary. Also note at the top of the picture is the old coil from my last setup.

I should've posted this sooner, it's a bit late now to spot the offenders, but there were way too many people putting up their Christmas lights early. An faux pas I've come to call a "false start". It's one of the unwritten man rules that you don't put up your decorations until after Thanksgiving Day (at least after the dinner on Thanksgiving Day). Just like everyone knows you're supposed to leave them up until after New Year's Day. You don't start too soon, you don't quit too early. It's like running a race, you start when everyone else does or you lose. You finish when everyone else does or you lose. (*and everyone knows that if you leave them up year-round, you've lost so badly you can never compete again)

Even if you're unable to have a family dinner on Thanksgiving Day and you eat a few days early, you still can't put your lights up until Thanksgiving Day. Otherwise it's a false start. It'd be like going over to eat at someone's house and they already have a Christmas tree up - you just don't do that until afterwards.

Retailers? They're immune to this rule because they, of course, have to be able to sell you decorations if you're going to put up your decorations on the day of Thanksgiving. But remember, just because you bought them early does not excuse you from having to wait until Thanksgiving to put them up.

Now that you can go ahead with your decorating, when you're done why not practice some holiday trick to show your friends and family?

For the past 8 years or so, I've had a Digital (DEC) brand keyboard that I procured "off the tree" from PC Outlet when Skaven, Roboprobe and I all worked there. I think it was Roboprobe that got ahold of it for me. I've sincerely loved that little beige keyboard. It has been the one keyboard I've used with Windows 98 on my K6-2+, to my K6-2 400, leet linux-learning machine, on up to my current Athlon64. It's been around, and has nasty oil-spots to show for it. I've seen some grimey keyboards, and I've tried to keep this guy clean, but some nastiness just doesn't come out. It was the one old part of my computer that just didn't look good - at all.

To match my sleek new monitor, I had to get a sleek, new keyboard. I wanted a black keyboard and I've always like the minimalist look of the Dell slim-line keyboards.

I looked on ebay for a Dell SK-8115 and found several. I found some were selling for $3 + s/h. In the end, it all worked out to about $10 for a cool, simple, new keyboard. I know, not everyone likes them, but I really like the way the keys feel as you type, it also has very quiet keys and looks nice too. So far so good.

Here's what the keyboard looks like.