Electronic Design

What's All This Floobydust, Anyhow? (Part 8)

Floobydust* season is here! (It's always the right time for Floobydust). This year I visited 16 countries. Every chance I had, I went to hardware stores. In NO place did I find any 1/4-in. electric drills—only 3/8 in. or 10 mm. Sounds like a conspiracy to me, that ALL manufacturers and sellers of nice, light, high-speed drills just happened to stop making them at the same time...I think I'll write to the Attorney General.

Slobber: Back in the 1960s (which I'm sure many of you remember), Tektronix wired most of their scopes in the 530 series, and the plug-in preamps, with the components soldered neatly into rows of little NOTCHED ceramic strips, etc. Somebody asked me: "Why did Tek recommend using silver solder to repair the components in these ceramic strips?"

Almost nobody knew the answer. But Jim Williams, an aficionado of old Tek scopes, recalled that if you had to make repeated solder repairs to any point, the metal could separate from the ceramic, causing flaky results. The silver solder could prevent this. But that silver solder was made up with 1% or 2% silver.

These kinds of solder typically melt in the range of 179° to 309°C. The silver solder used for soldering steel, with a borax flux, has 75% silver and melts at 1005° C; or if 56% silver, at 983°C. So, those two kinds of "silver solder" are quite a bit different.

Vice-Versa Stuff: I got more letters on "Vice Versa Stuff" (Electronic Design, Aug. 9, p. 107) than on most topics. Many ideas overlapped.

One reader pointed out that fully loaded ore trucks in an open-pit mine ascend on a CW spiral road. And it makes perfect sense to drive on the LH side, near the wall, to avoid breaking down the open edge of the road. The descending trucks, empty, drive near the dropoff.

But why are the CW spirals ascending? They could have made the spiral either way. The answer lies over 100 years back. When trucks were introduced to take over from ore trains, they followed the same CW spiral. It would be silly to reverse the spiral on existing mines.

OK—fine—WHY did the trains run on the left, on the ascent? That goes back over 120 years, and it may be hard to find an answer. I can't guess. Anyhow, the guy pointed out that all such trucks have lefthand drivers, even though they operate on the LH side of the road, in countries where other drivers may be LH or RH.

A couple guys gave the exact date of the RH changeover of Sweden as Sept. 3, 1967. There's info at www.docs.uu.se/~ei96pem/Hogertrafik/Innehall.htm that's quite educational—if you read Swedish.

As mentioned earlier, the web page at www.travel-library.com/general/driving/drive_which_side.html has over 15 pages about LH/RH driving. There's a complete list of all countries that drive on L or R and many historical items.

There, I learned that Napoleon did NOT cause France to change from L to R in 1805. France had been driving on the right for many years, well back before "recorded history." However, Napoleon did force many neighboring countries to change from L to R as he stormed around Europe.

But if the Roman army had all of Europe on the LEFT, France must have changed over sometime between 300 and 1700 A.D. Why? Meanwhile, the British did NOT change. Why not? Various possible theories and reasons have been proposed. Plus, Mr. Lucas argues that HE is not certain that the Romans did march on the left. He doubts if the reason I give is fully correct or accurate. I'll just have to look back in my files and find that old photograph showing the Roman armies marching on the left side of the road....

One sharp engineer pointed out that in a changeover such as Sweden's, you have to change the headlights. The patterns of headlight beams are DIFFERENT for LH/RH drive. Just one more reason I would not want to drive an English car in France, nor vice versa.

Y2WHAT?? A couple of readers thought I ought to write a column on Y2K. I declined, as I have no interest in writing on such digital subjects. And I can't think of much to say that hasn't been said 14 times.

I already bought my champagne. There's sure to be severe shortages of good champagne (at any reasonable price) for a couple years. I bought some rice and beans and put them in a mouseproof container, just in case stores get low on other food that's fancier, but not nearly so nutritious. Plus onions, garlic, and salsa for variety. I'll make sure I have a small stock —the usual two or three weeks—of medicines and prescription drugs, just in case. And candles, matches, and batteries. I have plenty of rechargeable ones, and I'll have my solar array nearby.

There is one caveat that only ONE guy told me, and I'll pass it along here: Please resist the temptation to jump on the telephone after your first sip of champagne. That surge will surely overload the switchboards and tie all the telephone companies in KNOTS. Just take it easy.

Throwing rocks? Gary Welch told me that he heard about a scientist who studied the patterns of the chips of tools that were several hundred thousand years old. He concluded that the makers were right- or lefthanded in about the same ratio as modern man. H'mmmm.

Tax-Deferred Stuff: I made a little error on the level of income where taxes become vicious: It is the TAXABLE income, not just the gross income at line 31, that has to be above $42k. It is the income after deductions and exemptions that's liable to be taxed at a 52% rate. I showed this column draft to 50 reviewers plus Mr. Klabis, and nobody noted my error. I think two readers caught this. Thanks for griping, guys.

WOM? Back about 1972, there was an excellent advertisement for the new WOM made by Signetics. A WOM (write-only memory) is a way to use up and dispose of otherwise unwanted bits. Looking at the text and the drawings, you could easily see that this was a rather witty parody of IC data sheets.

We all make those up from time to time. But THIS advertisement ran in at least one (maybe two?) electronics magazines, and was a four-page ad in full color. WOW, WOM!! Just two questions: Who made up the advertisement? Who the heck paid for it? (If Signetics did it, that sure was a nice sense of humor!)

All for now. / Comments invited!
RAP / Robert A. Pease / Engineer
[email protected]–or:

Mail Stop D2597A
National Semiconductor
P.O. Box 58090
Santa Clara, CA 95052-8090

* To those of you that haven't seen the term before, Floobydust is just an old name that we coined at NSC, meaning miscellaneous.

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