Crystal Radio Coil Size/Type Experiments 1-3 Remix

This video is a remix of my bobbin coil and followup up experiments on why it did not work. The redundancy between the individual videos has been cut. This is a useful summary of coil sizes/types and compares how well they work and don't work.
KNOWN STANDARD COIL:
- Wire size big: 0.81mm (20 AWG)(Done/standard) Straight wound
- Core: 42 mm (1.65") PVC plastic
- Inductance total: 205 uH (Measured)
- Taps: 0T, 20T, 30T, 80T
BOBBIN COIL (capacitively tuned version):
- Wire size fine: 0.227mm (31 AWG)(Done/standard) Multi-Layer Scatter Wound
- Core: 8 mm (0.314961") plastic
- Inductance total: 219 uH
- Taps: 0T, 10T, 15T, 40T
EXPERIMENT STRAIGHT WOUND 1.65" COIL
https://www.circuits.dk/multilayer-air-core-inductor/
Inductance (L): 205 uH
Coil Inner Diameter (d=2*r1): 42 mm
Coil Length (l): 15.73 mm
Wire Gauge: 0.227 mm 31 AWG (0.24717mm with insulation)
Number of Turns (N): 64 turns
Wire Length: 8.58 meters (x 1.3 if scatter)
DC Resistance (R): 3.68 Ω (at 20°C)
EXPERIMENT 1.65" COIL (SCATTER WOUND):
- Wire size fine: 0.227mm (31 AWG)(Done/standard) Scatter wound
- Core: 42 mm (1.65") PVC plastic
- Inductance total: 205 uH (Calculated)(220 uH measured after adjustment)
At 9.36 meters of wire, the original inductance was 360 uH.
1.8 meters of wire was removed to achieve 220 uH.
- Taps: 0T, 10T, 15T, 40T Total: 65T
- 10/65 = 0.154; 15/65 = 0.2308; 40/65 = 0.6154
- 10/65 = 0.154 (* 9.36m = 1.44m); 15/65 = 0.2308 (* 9.36m = 2.16m); 40/65 = 0.6154 (* 9.36m = 5.76m)
EXPERIMENT LONG COIL 8MM (STRAIGHT WOUND):
https://coil32.net/online-calculators/one-layer-coil-calculator.html
- Wire size fine: 0.227mm (31 AWG)(Done/standard) Straight wound
- Core: 8 mm (x") PLA plastic
- Inductance total: 205 uH Target (207 measured)
ENTER THE INPUT DATA:
L = 205 uH – Required inductance
D = 8 mm – Diameter of coil-former circumference = 25.13 mm
d = 0.227 mm – Diameter of wire without insulation 31 AWG
k = 0.24717 – Diameter of wire with insulation
RESULT:
N = 780.822 – number of turns
l = 192.997mm – Length of winding

Length of wire = 25.13mm x 780.822T = 19,622.05686mm or 19.6 meters
- 20T / 130T = 0.1538461538461538 (x 780.822T = 120.1265T) (x 19.6 m = 3.01539 m)
- 30T / 130T = 0.2307692307692308 (x 780.822T = 180.19T) (x 19.6 m = 4.5231 m)
- 80T / 130T = 0.6153846153846154 (x 780.822T = 480.5058T) (x 19.6 m = 12.0615 m)

Видео Crystal Radio Coil Size/Type Experiments 1-3 Remix канала tsbrownie