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Re: [TCML] JAVATC - questions
Hi Dennis,
Comments interspersed:
otmaskin5@xxxxxxx wrote:
Regarding the input for Primary Radius 2 (for a flat spiral primary),?do you enter the full radius (i.e., 1/2 the full diameter) of the primary...or some other number?? The reason I ask is,?the program Output Data shows Average Space Between Turns around 0.5".? I know my actual spacing isn't perfect, but it's not that far off.? I've gone back to measure with a ruler?& spacing is generally very close to 0.25" edge-to-edge.? Seems like the program is giving me center-to-center spacing,?or I'm?just entering something wrong.?
The program output for average spacing is edge to edge. For a flat coil,
radius 1 represents 1/2 of the inner diameter. Radius 2 represents 1/2
of the outer diameter. For example, an inner radius of 4" and an outer
radius of 8" using 8 turns of 0.25" tubing will result in an output
average spacing of 0.25" edge to edge. I think your entering something
incorrectly.
This?problem may be due to my not properly interpreting?the explanation diagram's R1/R2 terminology.? I could use clarification on this.
This may be my fault. The diagram shows R1/R2 for the flat coil case.
This isn't a division but meant that either R1 "or" R2 can be used for
inner or outer radius inputs. The reason is that some people wind flat
secondary coils and may connect ground on the inside or outside. Because
Javatc assumes radius 1 is the grounded end, you need to insert radius 1
as the actual grounded end (so in these flat coils where the rim is
grounded, we would insert the large outer radius into radius 1 and the
smaller into radius 2. That diagram can be confusing and certainly needs
updating. The diagram is used for both secondary and primary inputs.
For a standard flat primary, simply use radius 1 for the inside and
radius 2 for the outside.
Also,?the program sometimes changes the?value for Primary Radius 2?from what I had input.? I don't know why it does this or whether it means I'm doing something incorrectly.
You are allowing Javatc to tune your coil (the checkbox is checked).
When you allow Javatc to tune your coil, Javatc is basically moving the
tap point for you, from the outer most edge inward (or outward) until
the coil is in tune. It does this by unwinding the outer section (thus a
new radius 2 is inserted into the box) and evaluating the inductance. If
the tune point requires "less turns", radius 2 and the turns will
decrease. If the tune is point requires "more turns", radius 2 and the
turns will increase.
In the same respect, if you insert a desired coupling value, Javatc will
physically move the primary up or down as needed. In that case, both the
heights inputs will reflect new values.
Last question, the explanation text for primary inputs refers to connecting the the flat spiral primary to ground.? In my case, the primary is not connected to ground.? Rather, the end of the inside turn is connected to the tank cap and the other connection is the primary tap from the spark gap.? No primary coil connections to ground.? Will the program still work for this configuration?
Yes. The text is meant for secondary coils. Both the secondary and
primary use the same help files. I should have clarified that batter in
the pic. Most primary coils using NST's are not connected to ground.
Other transformers allow for a grounded inner primary turn. In either
case, don't worry about it. For the primary, inductance is the same
regardless (uses low frequency inductance). If it was a flat secondary
coil, then there would be a difference in the high frequency inductance
depending on which end is grounded which is where the secondary
frequency is derived.
Take care,
Bart
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