Thursday, June 24, 2010

Update on Blog

Sorry, all, for the big delays in posting. My wife delivered a 10lb, 7oz baby boy on June 14th... and the weeks before were a bit crazy as well as the last week and a half.

Baby and momma are fine, life is somewhat returning to normal, and I'm ready to get back to the blog and finish my coverage of the experiments in the book.

I'll try to have a conclusion/summary of Experiment 31 before Saturday... and I've been collecting my notes on Experiment 32 which appears to be one of the larger and more time-consuming exercises. I've been looking forward to that experiment ever since I first skimmed the book, so it's nice to have reached that point... now if I can just find some spare time to cut out the pieces.

Excuses, excuses... thanks for your patience, and I'll get back to work on the blog and book shortly.

Wednesday, June 2, 2010

Chapter 5 - Exercise 31

So we're going to build an AM radio with an empty bottle, lots of wire, a germanium diode, and a cheap earphone... sounds fun.

A few things - I didn't have a 3" diameter bottle, but a 2.5" Flinstone's Vitamins bottle, generously donated by my 3 year old son who allowed me to put the remaining vitamins in ziploc bag. Thanks, D!

After removing the label and cleaning the bottle, I drilled the holes as instructed. It's hard to tell from Figure 5-60 how tall that bottle is but I don't think my bottle is tall enough to hold the 12 "taps" that the instructions say to build... and because the bottle's diameter is less than 3", I multiplied by the 16 to get a 40" distance between taps. Doing a little math, I quickly figured out that 12 taps wasn't going to wrap around once I got started...

BTW, start at the bottom of the bottle and work your way up - it's easier to tie off the wire when you're done wrapping if the holes near the top are exposed - I managed to get my fingers through the bottle opening and get it tied off. The author recommends 22 gauge wire, solid core... I used insulated and I'm glad I did... makes it much easier to wrap and you'll save your fingers from wire-burn... yes, I made that term up, but exposed wire does get hot to your fingers when you're wrapping... your call.

After wrapping my bottle tightly, I managed to get 10 taps before running out of room... I don't think this will be an issue but may give me fewer chances of success when it comes to picking up a signal. As you can see, my taps aren't spaced as far apart as the author's are in Figure 5-64... crossing my fingers and hoping.

Up next, getting the antennae setup... I've got the germanium diode and earphone, so I need to get some rope that won't interfere with the antenane and keep it from grounding... more to come.