HP Forum Archive 20

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TI's "fake weight" Message #1 Posted by Cristian Arezzini on 24 Oct 2011, 7:11 a.m. I was at a flea market yesterday, and saw a calculator that looked interesting. It was a TI BAII Plus Professional, "advanced business analyst". I'm not a finance type, I know nothing about business, so I have no practical use for it; but it was in good condition, it felt solid and well-built, and at 5 euro it was cheap, so I bought it. I took it home and immediately disassembled it, to see how it is built. It does seem well-built enough - and the keyboard has a decent feedback, really usable - but I was amused to see that they screwed two heavy metal plates to the back shell, just to give it a more substantial feel. I mean, the weight doesn't come from solid casing and high-quality materials: but from something added just with the purpose of making you think it's solid! :) Personally I think it's a bit like cheating... like gold-plating a watch, or like putting a wing on a otherwise standard car, so that it just looks faster... But I do agree that it feels good to hold it! :) Cristian

Re: TI's "fake weight" Message #2 Posted by Paul Gaster on 24 Oct 2011, 7:48 a.m., in response to message #1 by Cristian Arezzini I don't think TI is the only one who does this. The pictures I have seen of the 15C LE show a black metal plate in the back housing. I can't think of any reason it would be there except to add weight. Of course for the LE the goal was to make it look, feel, and get the same results as the original, so I guess it is a special situation.

Re: TI's "fake weight" Message #3 Posted by Eric Rechlin on 24 Oct 2011, 3:47 p.m., in response to message #2 by Paul Gaster Usually thin metal is put inside for RFI protection. You don't need a thick metal plate, but a lot of HPs, including the 48, have a thin metal sheet/plate covering the board to meet FCC requirements. Eric

Re: TI's "fake weight" Message #4 Posted by Paul Gaster on 24 Oct 2011, 7:07 p.m., in response to message #3 by Eric Rechlin http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv020.cgi?read=196943 The 15C LE metal has a bunch of holes and does not cover even half of the pcb.

Re: TI's "fake weight" Message #5 Posted by db (martinez, ca.) on 24 Oct 2011, 8:14 p.m., in response to message #3 by Eric Rechlin Eric; I was once told that weight for weight or mass to mass, a mesh is better for rfi protection than a sheet. Is that true?

Re: TI's "fake weight" Message #6 Posted by Eric Rechlin on 25 Oct 2011, 1:56 a.m., in response to message #5 by db (martinez, ca.) The point is you don't want the holes so big that the RFI can get out at the wavelengths you are trying to block. You're basically building a Faraday cage. More holes = less material = cheaper. It's reached the point where the simplest materials (like plain metal) are a big factor in the cost of electronic devices, because the electronics have gotten so cheap and commodities have gotten so expensive. I think calculators these days probably emit so little RFI that there isn't a need for shielding anymore. Eric

Re: TI's "fake weight" Message #7 Posted by Katie Wasserman on 25 Oct 2011, 11:13 a.m., in response to message #6 by Eric Rechlin Early calculators that used inverter circuits to obtain the higher voltages needed for early MOS chips emitted a huge amount of RFI. I don't think that there were any RF emission standards for low power devices back then. For laughs take a broadcast band AM radio and put in next to an HP-35 then tune between stations. You can hear the 35 calculate!

Re: TI's "fake weight" Message #8 Posted by Ethan Conner on 25 Oct 2011, 12:07 p.m., in response to message #7 by Katie Wasserman When i was in high school i remember being able to hear my TI-30 on my am/fm cassette player.

Re: TI's "fake weight" Message #9 Posted by Palmer O. Hanson, Jr. on 26 Oct 2011, 12:58 a.m., in response to message #7 by Katie Wasserman Quote: For laughs take a broadcast band AM radio and put in next to an HP-35 then tune between stations. You can hear the 35 calculate! At one time someone proposed that the way to tell that a lengthy TI-59 calculation had finished without watching the display was to listen to a nearby radio. .

Re: TI's "fake weight" Message #10 Posted by Geoffrey Wang on 24 Oct 2011, 11:46 a.m., in response to message #1 by Cristian Arezzini I read somewhere that TI did this with their recent calculators like the TI36X. It's not cheating, but rather paying attention to customer feedback. I doubt most people would not want to buy a calculator with a bunch of keys and light weight (just like keyboards). I just wish Casio had done it with non-HP16C alternative, the CM-100.

Re: TI's "fake weight" Message #11 Posted by Cristian Arezzini on 24 Oct 2011, 1:52 p.m., in response to message #10 by Geoffrey Wang I didn't know this was common practice, but after all it makes sense. I can see why people like to have something that feels "heavy" in their hands. It's just that I would prefer if the weight came from a more substantial structure rather than an iron bar screwed to the shell! :) Cristian

Re: TI's "fake weight" Message #12 Posted by Thomas Radtke on 24 Oct 2011, 2:40 p.m., in response to message #11 by Cristian Arezzini Lightweight calculators are shirt pocket friendly. It is, after all, a *pocket* calculator, not one to fill a lead belt.

Re: TI's "fake weight" Message #13 Posted by Jeff Johnson on 24 Oct 2011, 3:57 p.m., in response to message #12 by Thomas Radtke Geoffrey and Cristian are spot on. It's not just calculators. Back when Bell Telephone went to electronic sets, users felt that the phones were "cheap" feeling, so Bell added metal plates to give it the "quality" feel. We have a paradigm that associates weight with quality. Much like the humorous problem with the HP-12C revision, where accountants were uncomfortable with the increased computation speed, afraid that the calculator was rushing through the calculation. They liked to see it "doing something".

Re: TI's "fake weight" Message #14 Posted by Bill Wiese on 24 Oct 2011, 4:01 p.m., in response to message #1 by Cristian Arezzini This is not unusual. QA testing may have found that without added weight it scooted over the desk when in use, perhaps. Weight also sometimes gives the perception of 'substance' and durability. When I was at Motorola, one person told me that Moto - who for decades has made durable police radios, walkie-talkies, etc. - in the late 80s was able to reduce the weight of their police walkie talkies simply due to integration and materials changes. In no way was durability or lifespan affected. But reports of 'issues' and quality drops kept coming in - after investigation, there was no substantiation but somehow "lightweight" kept coming up. Moto put some weights inside the radios without anything else changing, and the complaints stopped. Perception is a nasty beast. Bill Wiese San Jose CA

Re: TI's "fake weight" Message #15 Posted by BobVA on 24 Oct 2011, 6:00 p.m., in response to message #14 by Bill Wiese ...and don't get me started on 1970's audio gear (slate end plates, pot metal ballast inside turntables, etc.) :-) Bob

Re: TI's "fake weight" Message #16 Posted by Lincoln R. on 25 Oct 2011, 12:25 a.m., in response to message #15 by BobVA There's another more practical reason for putting weights in things. The weights make it less likely that the object will move when said movement is undesirable (for instance one would not want their calculator to go sliding around the desk when they push a button, or have a rotary dial phone spin when they try to turn the dial). For that matter, my dishwasher has a large concrete block (I kid you not) zip-tied to the bottom part of the metal frame. The block does nothing for cleaning dishes, nothing for appearance, and I doubt anyone ever says "these darn lightweight dishwashers are junk."

Re: TI's "fake weight" Message #17 Posted by Jose Gonzalez Divasson on 25 Oct 2011, 3:55 p.m., in response to message #15 by BobVA There is a school of audio enthusiasts that claim that adding weight to audio components improve sound, by lowering their resonance frequency to below audio band. Hence, you see weights in turntable platters, lead shot in hollow tubes in audio racks, 150lbs loudspeakers, and so on. There is another school that aims to low mass - and trying to have the q of that mass as low as possible (light woods, composites), trying to get a low resonance peak, but avoiding energy storage and therefore delayed release. Another world altogether!

Re: TI's "fake weight" Message #18 Posted by Michael Meyer on 26 Oct 2011, 5:17 p.m., in response to message #17 by Jose Gonzalez Divasson I suppose that's the reason I'm heavier than I used to be--- to give the impression of increased quality!

Re: TI's "fake weight" Message #19 Posted by Ren on 27 Oct 2011, 2:41 p.m., in response to message #14 by Bill Wiese IIRC, back on the old USENET ham radio group, someone told the story of repairing an old handheld Motorola that a cop frequently used as a "billy club". It would arrive in the repair shop with bits of hair or skin stuck to knobs.

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