50 - 51 MHz 4 kW Low Loss Bandpass Filter BPF

  • 50 - 51 MHz 4 kW Low Loss Bandpass Filter BPF

50MHz 4kW Low Loss Bandpass Filter BPF

6m Bandpass Filter BPF uses high Q coils and capacitors with Q more than 4000. Low loss of filter is achieved with careful design and adjustment.

Intended to be used with linear amplifiers 8877, GS35, GS31, 2xGI7B and with other tubes up to 4 kW output.

Although intention of this filter is to be used as transmitting filter, design allows also to be used as receiving filter. It can be used before Wide Band VLNA with SPF-5122Z or Wide Band LNA with PGA-103+ to protect sensitive device from strong out of band signals. Excellent results will be achieved before wide band SDR receivers to monitor 6 meters band.

Insertion loss is excellent to put before any LNA or protect receiver from HF transmitters in DX expeditions or in multi-multi environment. This BPF will suppress any harmonic on 100 MHz, 150 MHz and more + protection from HF stations.

Although this indoor and this outdoor RX Band-Pass filters are better for only receiving, this Low Loss Bandpass Filter works very good both ways.


The recorded data on the assembled filter with HP8753ES network analyzer full 2-port calibrated are presented below.

Measured Return Loss - S11 (CH 1) and Insertion Loss - S21 (CH 2). Characteristics of 50 MHz Bandpass filter for up to 4000 W transmitter.


Achieved results on build Band-pass Filter (Attenuation)

HF Band

1.8 MHz 3.5 MHz 7 MHz 14 MHz 21 MHz 28 MHz
- 98 dB - 87 dB - 72 dB - 53 dB - 44 dB - 34 dB

Bandwidth: 50 - 51 MHz

50 MHz 50.11 MHz 50.25 MHz 50.5 MHz 51 MHz
- 0.08 dB - 0.08 dB - 0.078 dB - 0.075 dB - 0.08 dB

FM attenuation

88 MHz  98 MHz  100 MHz 104 MHz 108 MHz
- 38 dB - 44 dB - 42 dB - 41 dB - 40 dB

144 MHz / 432 MHz Band Attenuation

144 MHz 146 MHz 430 MHz 440 MHz
- 41.5 dB - 42 dB - 48 dB  - 49 dB

These excellent results were achieved by careful selection of components and design of the filter. Band Pass filter will eliminate any harmonic emission from your linear amplifier.
More measured results with HP8753ES network analyzer full two port calibrated.
1. Measured HF Attenuation

2. Harmonic and FM attenuation.

3. A wide range is displayed. Here you can see 144 MHz and 432 MHz attenuation of 50 - 51 MHz 4000 W Bandpass Filter.

1500 W and 4000 W filters share same high quality components except connectors, fan, and different design of aluminum box. Link to 1500 W Band-pass filter and picture of both is presented down below.

Similar VHF band pass filters:

6 meter band, 50 MHz Economical Bandpass Receiver for Ham: 50 - 51 MHz Economical, Low Loss Bandpass Filter

6 meter band, 50 MHz Receiver Bandpass for Ham: 50 - 51 MHz High Selectivity, High Q, Low Loss RX Bandpass

6 meter band, 50 MHz Receiver Outdoor Bandpass: 50 - 51 MHz High Selectivity High Q, Low Loss RX Bandpass - Outdoors

6 meter band, 50 MHz,300 W Bandpass for Ham: 50 - 51 MHz 300 W Low Loss Bandpass Filter

6 meter band, 50 MHz, 1500 W Bandpass for Ham:50 - 51 MHz 1500W Low Loss Bandpass Filter

We are also making filters on all frequencies and powers. Even if we don't have an offer on our site, we may be able to make it for you. So feel free to contact us via email.

You might also like to read about our 6 meter band antennas (50 MHz): 6 Meter High Gain Low Noise Antennas

  • Product Code: 0631
  • Availability: In Stock
  • 209.00€

Tags: 50MHz, 51MHz, 6m, 6meters, VHF, BandPass, RFI, Band-Pass, Filter, BPF, High, Q, Selectivity, Low, Loss, 4000W, 4kW, Transmitter, Field, Day, Ham, Radio