2 meter 144 MHz – 148 MHz 4 kW <0.1 dB Low Loss Transmitting Band Pass Filter with 7/16 DIN connectors

2-meter Bandpass Filter BPF uses high Q coils and capacitors with Q of more than 4500. Low loss of filter achieved with careful design and adjustment.

Although the intention of this filter is to be used as a transmitting filter, the design allows also it to be used as a receiving filter before wideband LNA to protect sensitive devices from strong out-of-band signals. Like this.

Intended to be used with linear amplifiers. Some examples are 8877, GS35, GS31, OM1002+, and OM2002+, as well as with other tubes or transistors up to 4 kW output.

Super low insertion loss. Excellent to put before any LNA or protect the receiver from HF transmitters in DX expeditions or in multi-multi environments. This BPF will suppress any signals from HF 1.8 – 28 MHz stations, 50-54 MHz, 70 cm – 432 MHz (430 – 440 MHz).

This filter uses a 7/16 DIN connector type. Similar Low Loss Band Pass Filter designed for 1500 W linear power output that uses “N” connectors.

The filter will reduce TVI problems or your problem with neighbors with strong RFI from HF, 6-meter, or 70-cm transmitters.

 

 

Achieved results on a built Band-pass filter:

1.8MHz=-100 dB
3.8MHz=-91 dB
7.1 MHz = -81 dB
14 MHz = – 67dB
21MHz= -58dB
28 MHz = -51 dB
50 MHz = -34 dB
54 MHz = -31 dB
144 MHz = -0.09 dB
145 MHz = -0.086 dB
146 MHz = -0.09 dB
148 MHz = -0.089 dB
Harmonics and interfering signals:
288 MHz = -35 dB
296 MHz = -35 dB
430 MHz = -40 dB
432 MHz = -41 dB
440 MHz = -42 dB
576 MHz = -36 dB
720 MHz = -34 dB
880 MHz = -33 dB (GSM – Mobile phone)
930 MHz = -31 dB (GSM – Mobile phone)
960 MHz = -29 dB (GSM – Mobile phone)
1296 MHz = -17 dB

These excellent results were achieved by carefully selecting components and designing the filter.
Band Pass filter will suppress any harmonic emission from your linear amplifier.

Measured data on the assembled filter with HP8753ES network analyzer full 2-port calibrated.

Measured Return Loss – S11 (CH 1) and Insertion Loss – S21 (CH 2). Characteristics of 144 MHz Transmitting Bandpass filter.

 

 

1. HF Suppression for 144 – 146 MHz 4000 W Band-pass filter:

2. Suppression on 50 MHz (6 Meter band) for 144 – 146 MHz 4000 W Band-pass filter.

3. Measured data of 144 – 146 – 148 MHz Low Loss RFI band-pass filter. Insertion loss – S21 (Attenuation).

4. Suppression of harmonics and interfering signals:

 

Feel free to send e-mail if you need something more specific.

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

Direct link to all 2-meter filters. We have 50 W, 100 W, 200 W, 300 W, 1500 W and 4000 W versions: 2 Meter Band-Pass Filters