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HF LINEAR RF POWER AMPLIFIER

Low pass filter

Page 3 of 5

In constructing the RF coils for The Low-pass Filter Unit which is almost a band-pass because of 3 diferent trap frequency occured in each coil, I used 3/8" OD Toroids and used a Dip meter to adjust the winding of the coil appropriate to the pre- calculated/determined notch frequency and capacitance as shown in the picture. By this I got a table chart as shown below. And thanks to Microsoft Excel that simplified the calculation jobs.

Kumparan untuk LPF yang hampir berupa BPF karena adanya 3 frekwensi jebakan disetiap kumparan, saya gulung melilit toroid ukuran 3/8 inci dan mengatur jumlah lilitan dengan menggunakan Dip meter pada frekwensi jebakan dan kapasitor yang sudah dihitung/ditentukan terlebih dahulu. Dengan ini saya memperoleh daftar seperti dibawah ini.. Dan sukur berkat Microsoft Excel menjadikan pekerjaan ini lebih mudah.

BAND L 1 L 2 L 3 C 1 C1a C 2 C2a C 3 C3a C4 C4a C 5 C5a C 6 C 7 C7a
160 m
2.665
L4.10
4.355
620
X
100
1200
680
910
1300
1000
430
X
150
1000
220
80 m
1.41
1.56
2.32
330
47
300
180
1000
X
180
47
1000
180
82p
560p
82p
40 m
0.70
1.095
1.159
180p
X
240p
X
470
33
82
33
470
120p
39
200
110
20 m
0.339
0.525
0.556
75
X
120
X
240
X
39
15
200
82
18
100
39
15 m
0.236
0.374
0.386
56
C1a
82
C2a
150
18
39
C4a
180
18
12
96
C 7a
10 m
0.165
0.26
0.269
39
C1a
56
C2a
120
C3a
27
C4a
100
33
10
68
C 7a
All Inductance (L1,L2 and L3 ) are Toroidical coils arbitrary calculated in µH
All Cap are in pF dipped mica 500 WV unless otherwise specified
Relay = OMRON type 62K

Low Pass Frequency Band Channel Parts Table

Band 160 m = 1,6 mHz - 2.2 mHz
Band   80 m = 3.0 mHz - 4.2 mHz
Band   40 m = 6.0 mHz - 8.7 mHz
Band   20 m = 12.5 mHz - 18 mHz
Band   16 m = 18 mHz - 34.5 mHz
Band   10 m = 24.5 mHz - 32 mHz

LPF Printed circuit viewed from solder side LPF Printed Circuit viewed from component side
11.5 x 13 cm