Slide Rules

It seems like I recall two types. There was the one withthe linear scale ( radio shack ) and another with log scales.Dwight > > Well, I assumed it was doing a simple V R ratio / sum-of-logs of two > of the controls with a null-point balance with the third, however one > of the sites on the web showed a bag of caps and transistors involved > in the construction so perhaps it's using some AC principle, or that > may be a mislead. > > I'm going to try to find the PE article in the library at the radio > museum this afternoon. > > > On 2013 Mar 10, at 11:50 AM, dwight elvey wrote: > >> I did some searching on the web but I was surprisedthat no one has >> posted a schematic for it.Dwight >> >>> Actually, after giving it a little thought, it would use >>> linearpots and scales. It would be voltage dividers and a >>> balancingmeter.Remeber, a pot forms a ratio across a >>> resistor.Dwight >>>>>> >>>> >>>> That's what I was expecting, but looking at the dial (as much >>>> as one >>>> can see in the photos), they appear to be linear, so I figured it >>>> was >>>> taking advantage of log pots (or is there a log/anti-log problem >>>> there anyways?). Considering it more, a typical log pot may not >>>> give >>>> an accurate enough log function to be very good for the task, so >>>> you're probably right. Maybe there's another principle involved. >>>> >>>> Another web site refers to a popular electronics article with a >>>> similar design (I think I've seen the article in the past) but >>>> doesn't say which issue. >>>> >>>> >>>> On 2013 Mar 8, at 8:58 PM, dwight elvey wrote: >>>>> Actually it makes more sense to use alinear one with log >>>>> scales on >>>>> the dial.Dwight >>>>>>>>>>> ---snip--- >>>>>> >>>>>> I like how the box says "As accurate as a slide-rule". >>>>>> >>>>>> Presumably it uses standard log pots, aka volume controls.