2m 144 to 148 MHz 300 W Transmit – Receive Bandpass Filter

Intended for use with linear amplifiers up to 300 W output, or before any wide band low noise amplifier (LNA) to protect from any out-of-band signals. Bandpass filter BPF uses high Q coils as well as high Q capacitors. Low loss of filter is achieved with careful design and adjustment.

This filter is equally good as a transmitting and receiving low-loss filter (0.14 dB). 

The filter will reduce TVI problems or your problem with neighbors with strong HF, 6 m, 4m, or 70 cm transmitters.

 

Achieved results on a built Band-pass filter:

Attenuation: 

1.8 MHz < -109 dB
3.8 MHz < -106 dB
7.1 MHz < -104 dB
14.15 MHz < -86 dB
21.2 MHz < -75 dB
28.4 MHz < – 67 dB
50.1 MHz < -50 dB
54 MHz < – 48 dB
70.2 MHz < -38 dB
88 MHz < -27 dB
98 MHz < -21 dB
108 MHz < -13 dB
144 MHz = -0.14 dB, RL -35dB
146 MHz = -0.14 dB, RL -35 dB
148 MHz = -0.14 dB, RL -35 dB
222.1 MHz < -23 dB
288.2 MHz < -38 dB
432.3 MHz < -49 dB

Maximum power input at SWR:

1:1 = 300 W; 1:1.5 = 210 W; 1:2 = 175 W; 1:3 = 140 W

 

Measured HF Attenuation of 144 – 148 MHz 300 W Band pass filter:

 

 

2m 300W Transmit – Receive Low Loss Narrow Bandpass Filter 144-148MHz:

 

 

2m 300W 144-148MHz Bandpass Filter 6m, 4m, 2m, 1.25m, and 70cm Attenuation:

 

2m 300W 144-148MHz Transmitting and receiving Bandpass Filter Zoomed

All band-pass filters are here: HF, VHF and UHF Band-Pass Filters

Link to all 2-meter filters. 50 W, 100 W, 200 W, 300 W, 1500W, 4000W and 5000W versions: 2 Meter Band-Pass Filters