Kits and Parts Lowpass Filter
Contents
Parts and Kits Filter
- 7-pole Universal Low Pass Filter for HF
- 2nd-Harmonic-Optimized LPFs by By Ed Wetherhold, W3NQN - Built this one
- Introduction to LPFs by Paul Hardin, NA5N
- 7 Element Chebyshev standard value capacitor LPFs
- Toroid Coil Winding Calculator
- T37-2 Toroid Specs
- T80-2 Toroid Specs
- LC Filter Design Tool
K&P Schematic
K&P PCB
CWAZ 40M, 7 MHz Filter
- Based on 2nd-Harmonic-Optimized LPFs by By Ed Wetherhold, W3NQN - Built this one
SPICE Simulation
- GitHub repo
- -6 dB at 7 MHz
- -68 dB at 1st harmonic (14 MHz)
- -75 dB at 2nd harmonic (21 MHz)
T37-2 Inductors
INDUCTANCE - L1, L3
- Desired: 1.34 uH
- Calculated: 1.3 uH (97% of desired) Turns required: 18
- CORE
- Part number: T-37-2 (Red)
- Frequency Range: 1 to 30 MHz
- u: 10
- AL: 40 uH/100 turns
INDUCTANCE - L2
- Desired: 1.22 uH
- Calculated: 1.2 uH (95% of desired) Turns required: 17
- CORE
- Part number: T-37-2 (Red)
- Frequency Range: 1 to 30 MHz
- u: 10
- AL: 40 uH/100 turns
Measured on NanoVNA
- 7 MHz LP filter
- Built with junk box low voltage ceramic disc caps
Rebuild
- T80-2 Inductors
- Larger gauge wire
- Integer turns values
- High voltage quality caps
- Ceramic - should these be silver mica caps?
- Will the ceramic caps cause Microphonics?
Caps
| Capacitance (pF) | Mfr. # | Manufacturer | Description |
|---|---|---|---|
| 10 | S100K33SL0R63K7R | Vishay | Ceramic Disc Capacitors 10pF 3000V 10% SL0 7.5mm LS |
| 33 | CC45SL3AD330JYNNA | TDK | Ceramic Disc Capacitors D: 5.5mm 1kV 33pF SL 5% LS:5mm |
| 47 | CC45SL3AD470JYVNA | TDK | Ceramic Disc Capacitors D: 5.5mm 1kV 47pF SL 5% LS:5mm |
| 82 | CC45SL3AD820JYNNA | TDK | Ceramic Disc Capacitors D: 6mm 1kV 82pF SL 5% LS:5mm |
| 100 | CC45SL3AD101JYNNA | TDK | Ceramic Disc Capacitors D: 6.5mm 1kV 100pF SL 5% LS:5mm |
| 120 | CC45SL3AD121JYNNA | TDK | Ceramic Disc Capacitors D: 7mm 1kV 120pF SL 5% LS:5mm |
| 200 | S201K33S3NN63L6R | Vishay | Ceramic Disc Capacitors 200PF 1KV 10% |
| 270 | CC45SL3AD271JYVNA | TDK | Ceramic Disc Capacitors D: 9mm 1kV 270pF SL 5% LS:5mm |
| 330 | S331K33Y5PR63K7R | Vishay | Ceramic Disc Capacitors 330pF 3000V 10% Y5P 7.5mm LS |
| 390 | CC45SL3AD391JYVNA | TDK | Ceramic Disc Capacitors D: 10.5mm 1kV 390pF SL 5% LS:5mm |
| 470 | D471K20Y5PH6UJ5R | Vishay | Ceramic Disc Capacitors 470pF 100V 10% |
| 680 | S681K29Y5PN63J5R | Vishay | Ceramic Disc Capacitors 680pF 1000V 10% Y5P 5.0mm LS |
