4m 70MHz 300W High Power Low Loss Bandpass Filter

  • 4m 70MHz 300W High Power Low Loss Bandpass Filter

70 - 70.5 MHz 300 W Low Loss Transmitting Band Pass Filter for 4 Meter band


Intended to be used with transceivers like Icom IC-7100, Yaesu FT-847, transverters and linear amplifiers up to 300W output.

Although intention of this filter is to be used as transmitting filter, design allows also to be used as receiving filter before wideband LNA to protect sensitive device from strong out of band signals.

This BPF will suppress any signals from HF 1.8 - 28MHz stations 50-54MHz, FM, 144 MHz and 432MHz (430 - 440MHz).

Filter will reduce TVI problem or your problem with neighbours with strong HF, 6m, 88-108MHz, 2m or 70cm transmitters.

Here are presented measured results with HP8753ES network analyzer full two port calibrated.

Measured Return Loss - S11 (CH1) and Insertion Loss - S21 (CH2). Characteristics of 70 - 70.5 MHz Bandpass filter for up to 300 W Transmitter. 


Achieved results on a built Bandpass filter:

1.8 MHz < -100 dB
3.8 MHz < -100 dB
7.1 MHz < -100 dB
14.15 MHz = -84 dB
21.2 MHz = -73 dB
28.4 MHz = - 64 dB
50 MHz = -36 dB 
51 MHz =- 34.5 dB
70 MHz = -0.24 dB
70.1 MHz = -0.24 dB
70.25 MHz = -0.24 dB
70.5 MHz = -0.25 dB
Harmonics and interfering signals:
88 MHz= -25 dB
98 MHz= -36 dB
108 MHz= -41 dB
140.2 MHz = -54 dB
144.1 MHz = -55 dB
432.1 MHz = -62 dB 
These excellent results were achieved by careful selection of components and design of the filter.
Band Pass filter will suppress any harmonic emission from your transceiver or linear amplifier.
More measured results with HP8753ES network analyzer full two port calibrated.
SWR is displayed. The Range shown is from 70 MHz to 70.5 MHz:
4 Meter Band. You can see flatness of insertion loss on working frequency:
Suppression of harmonics and interfering signals on VHF and UHF:

You can search our similar VHF bandpass products for 4 meter band here:

4 meter band, 70 MHz Receiving Band-pass filter for Ham radio:    70 - 70.5 MHz Low Loss, Low Cost Receiving 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 4 meter band antennas (70 MHz):    4 Meter band High Gain Low Noise Antennas

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  • Product Code: 0641
  • Availability: In Stock
  • 159.00€

Tags: 70 MHz - 70.5 MHz, 4m, 4 meters, VHF BandPass, RFI Band-Pass filter, BPF, High Q, 300 W, Low Loss Band Pass, Field Day Filter, Ham Radio Filter