Experiments with LC circuits    part 2

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The next experiment is made with basket weave coil L6.
The tuner capacitor is C1b.

Coil L6.

This coil has no coilformer.
The wirelength on the coil is 12.5 meter, and two leads of 0.25m.
So, the total wirelength is 13.0 m.
The inside diameter is about 11 cm.
Number of turns: 32.
Wire: litz 40x0.07mm
The intersections of the wires are glued together

Measurement 
number
LC combination  F min 
kHz
F max 
kHz
Q
600 kHz 
Q
900 kHz 
Q
1200 kHz 
Q
1500 kHz 
12 L6 C1b 512 2075 317 340 279 243

 


In the next experiment the coil is divided over two coilformers.
The outside diameter of the coil is now reduced, and the receiver can be build more compact.
The distance between the coilformers is adjustable, I made measurements with distances of 10, 20 and 40 mm.

 

Coil L7

This coil has two coilformers of foam PVC.
Each former is wound with 6.25 meter wire, and there are two leads of 0.25 m.
Total wirelenght is 13.0 meter.
Wire: litz 40x0.07 mm.
Number of turns: 29 per former, so total of 58.
Inside diameter of the coil: 50 mm.
The coil must be wound on both formers in the same direction.

Measurement 
number
LC combination  F min 
kHz
F max 
kHz
Q
600 khz 
Q
900 kHz 
Q
1200 kHz 
Q
1500 kHz 
13 L7 C1b
10mm distance
460 1926 332 324 265 220
14 L7 C1b
20 mm distance
511 2190 287 334 255 224
15 L7 C1b
40mm distance
550 2370 283 301 255 216

 


The next coil has less wire then the coils before.

Coil L8

The wirelenght on the former is 6.5 meter, and the two leads are 0.25 meter.
Total wirelenght is 7 meter.
Wire: litz 40x0.07 mm.
Coilformer material: foam PVC.
Coil inside diameter: 50mm.
Number of turns: 30.

 

Measurement 
number 
LC combination  F min 
kHz
F max 
kHz
Q
600 kHz 
Q
900 kHz 
Q
1200 kHz 
Q
1500 kHz 
16 L8 C1b 816 3490 * 303 287 269

Because of the shorter wirelenght, the minimum frequency is not very low, but the Q at 1200 and 1500 kHz is higher then all coils before.


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