Old PI network coil
"K7ITM" wrote in message
...
No, since the inductance, however it's achieved (that is, whether the
coil is one constant pitch or multiple pitches or continuously
variable pitch), is constant for a given switch setting. The reason
for the "variable" pitch in a tapped PI network coil is so that the
lower inductances for the higher frequencies don't end up being coils
that are very short compared with their diameter.
Ah, thanks Tom! That makes a lot of sense.
(Yeah, and I like 1957 prices for cars, houses, gas, bread,
coffee, ... -- but I like 2011 prices for what you get in consumer
electronics, for sure!)
There were scans on alt.binaries.pictures.radio, I think it was, from the WWII
era where Admiral Radio had these futuristic drawings of what the radio and TV
of tomorrow would look like, assuring you that's what they'd be bringing you
once the war was over and their factories could be put back to such uses: The
picture shows a projection screen that looks to be all of 25" or so along with
a projector in the center of the couch that's the size of a large dog. So
they did have the right idea, just the wrong sense of scale. :-)
---Joel
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