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# Analysis of a Kenwood TS 440 filter unit.

Updated: Dec 6, 2020

### How does it work?

Depending on the selected frequency, one of the six available filters is activated. This is done by controlling a relay at the input and a relay at the output.

**1 = 1.6 ==> 2.5 MHz**

**2 = 2.5 ==> 4.0 MHz**

**3 = 4.0 ==> 7.5 MHz**

**4 = 7.5 ==> 14.5 MHz**

**5 = 14.5 ==> 22 MHz**

**6 = 22 ==> 30 MHz**

### The setup:

### Measuring results:

### Insertion Loss Filter 1:

### At 1.8 to 2 MHZ Insertion loss is 0.4 dB. This means a loss 8.8 %. When transmitting with a power of 100 Watts, 8.8 watts will be lost in this filter.

### Harmonic suppression:

### second harmonic of 1.8 MHZ is 3.6 MHz = 17dB

### second harmonic of 2 MHZ is 4 MHz = 31dB

### third harmonic of 1.8 MHZ is 5.4 MHz = 46dB

### third harmonic of 2 MHZ is 6 MHz = 56dB

### Insertion Loss Filter 2:

### At 3.5 to 3.8 MHZ Insertion loss is 0.18 dB. This means a loss 4 %. When transmitting with a power of 100 Watts, 4 watts will be lost in this filter.

### Harmonic suppression:

### second harmonic of 3.5 MHZ is 7 MHz = 16.5dB

### second harmonic of 3.8 MHZ is 7.6 MHz = 27dB

### third harmonic of 3.5 MHZ is 10.5 MHz = 56dB

### third harmonic of 3.8 MHZ is 11.4 MHz = 52dB

### Insertion Loss detail Filter 2:

### Insertion Loss Filter 3:

### At 7 to 7.2 MHZ Insertion loss is 0.4 dB. This means a loss 8.8 %. When transmitting with a power of 100 Watts, 8.8 watts will be lost in this filter.

### Harmonic suppression:

### second harmonic of 7.2 MHZ is 14.4 MHz = 50dB

### third harmonic of 7 MHZ is 21 MHz =39dB

### third harmonic of 7.2 MHZ is 21.6 MHz = 39dB

### Insertion Loss detail Filter 3:

### Insertion Loss Filter 4:

### At 14 MHZ Insertion loss is 0.3 dB. This means a loss 6.5 %. When transmitting with a power of 100 Watts, 6.5 watts will be lost in this filter.

### Harmonic suppression:

### second harmonic of 14.5 MHZ is 29 MHz = 40dB

### third harmonic of 14 MHZ is 42 MHz =73dB

### third harmonic of 14.4 MHZ is 43.2 MHz = 63dB

### Insertion Loss detail Filter 4:

### Insertion Loss Filter 5:

### At 21 MHz to 21.5 MHZ Insertion loss is 0.4 dB. This means a loss 8.8 %. When transmitting with a power of 100 Watts, 8.8 watts will be lost in this filter.

### Harmonic suppression:

### second harmonic of 21 MHZ is 42 MHz = 27dB

### second harmonic of 21.5 MHZ is 43 MHz = 29dB

### third harmonic of 21 MHZ is 63 MHz = 53dB

### third harmonic of 21.5 MHZ is 64.5 MHz = 57dB

### Insertion Loss detail Filter 5:

### Insertion Loss Filter 6:

### At 28 MHz to 30 MHZ Insertion loss is 0.4 dB. This means a loss 8.8 %. When transmitting with a power of 100 Watts, 8.8 watts will be lost in this filter.

### Harmonic suppression:

### second harmonic of 28 MHZ is 46 MHz = 34dB

### second harmonic of 30 MHZ is 60 MHz = 43dB

### third harmonic of 28 MHZ is 84 MHz = 39dB

### third harmonic of 30 MHZ is 90 MHz = 41dB

### Insertion Loss detail Filter 6:

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