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:
4 meter band, 70 MHz Receiving Band-pass filter for Ham radio: 70 - 70.5 MHz Low Loss, Low Cost Receiving Bandpass Filter