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"Lisa Simpson" ) writes:
It makes perfect sense to have to guess at, or calculate, the frequency you're tuned to, when it would have been just as easy to actually display the actual frequency you're listening to? Assuming you are talking about radios without digital displays, I should point out that they weren't left off old radios for some vague reason. They were left off because digital displays would require a huge chassis for all the tubes to make the digital display, and of course that would drive up the cost so it would be beyond the means of most people. You could go with a mechanical digital dial, but you then either have the National HRO (complete with plug-in coils for each band) which was expensive, but still didn't give linear readout. It cost too much, and was too complicated, to make each band linear, so the fine numbers on the dial were just really good logging scales (and reasonably decent readout). There were expensive receivers like the R390 that had mechanical digital dials. They fixed the problem by having the dial cover a fixed and small range (500KHz), and then adding a converter ahead of it to get all the bands. It was much easier to get linear tuning, so the digital dial reflected the frequency accurately, with such a scheme. But it cost money to pay people to get the tuning linear, and thus no hobbyist could afford those receivers until they were available in surplus. Note that the same scheme did provide pretty good dials without the mechanical digital readout. But again, it was far easier to calibrate the dial every 1KHz (and be accurate) when the tuning only covered a small range and didn't change when the band changed. In the old days, dial accuracy and precision went up the more you spent on a receiver. What's misleading is that solid state electronics have made digital dials easy and cheap and small, so much so that it's now easier to use them than trying to do an analog dial. But just because a receiver has a digital readout now doesn't actually mean it's a good receiver. They are just as bad as the low end receivers of decades ago, albeit with a better dial. A good receiver can be expensive. Michael |