Experiments with LC circuits

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 wire length on the coil is 12.5 meter, and two leads of 0.25m.
So, the total wire length 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 wire length 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 wire length on the former is 6.5 meter, and the two leads are 0.25 meter.
Total wire length 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 wire length, 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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