Looking for any information on an Illumitronx Pi network "PI air dux" , part
number 1212D6 like power ratings, recommended taps / tube, etc. Looks like
#12 silver plated wire.
Not sure of the spelling but it looks to be Illumitronx. Google turned up
nothing.
Bob
KB8TL

Yes, I know how to measure or calculate inductance of an air wound coil

Never mind, found it!
http://glowbugs.net/AirDux.pdf

"Bob" wrote in message
...
Looking for any information on an Illumitronx Pi network "PI air dux" ,
part number 1212D6 like power ratings, recommended taps / tube, etc. Looks
like #12 silver plated wire.
Not sure of the spelling but it looks to be Illumitronx. Google turned up
nothing.
Bob
KB8TL

Yes, I know how to measure or calculate inductance of an air wound coil

"Bob" wrote in message
...
Never mind, found it!
http://glowbugs.net/AirDux.pdf

Would it be a correct assumption that the vari-pitch Air-Dix coils were used
with whatever-the-then-common variable capacitor was to achieve linear tuning
(...I realize that over time capacitors were purposely made to have non-linear
capacitnace with respect to dial position to achieve this as well...)? Or
something else?

I like the 1957 prices. :-)

On Mar 2, 9:17*pm, "Joel Koltner" wrote:
"Bob" wrote in message

...

Never mind, found it!
http://glowbugs.net/AirDux.pdf

Would it be a correct assumption that the vari-pitch Air-Dix coils were used
with whatever-the-then-common variable capacitor was to achieve linear tuning
(...I realize that over time capacitors were purposely made to have non-linear
capacitnace with respect to dial position to achieve this as well...)? *Or
something else?

I like the 1957 prices. :-)

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. A good way to put
it is perhaps that the unloaded coil Q is more constant over the
various bands, if you use a larger pitch (wider spacing) for the coil
section that will remain unshorted on the higher frequency bands.

Cheers,
Tom

(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!)

"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

On Mar 2, 5:21*pm, "Bob" wrote:
Looking for any information on an Illumitronx Pi network "PI air dux" , part
number 1212D6 like power ratings, recommended taps / tube, etc. Looks like
#12 silver plated wire.
Not sure of the spelling but it looks to be Illumitronx. Google turned up
nothing.
Bob
KB8TL

Yes, I know how to measure or calculate inductance of an air wound coil

It is a 1000 watt coil, that's rated in input power by the way, back
in those days they went by input power, I got's an AirDux coil I
bought on ebay it was mounted on a lucite board that went thru the
middle length wise of the coil, had the 10 meter flat wire coil on the
one end the ten meter coil is rated 1000 watts the ten meter coil was
mounted in a plane 90 degrees from the main coil.
Like if the main coil was north south the ten meter coil was going
east west
The main coil is 12 AWG silver plated wire the spec. sheet that came
with it stated that it was used for 1000 watt input power finals.