Chinese 200 Watt Band Pass Filters

Aliexpress and now other online websites sell these 200 watt band pass filters for around 50 USD (+/- $15). Definitely one of my more expensive and high risk purchases on aliexpress.

The filters themselve turn out to be closely to what is advertised. SWR is below the promised 1.5. The pass band attenuation is around -0.5 to -0.6 dB. Some of the sellers have screen shots of the attenuation across the spectrum. These show a sharp drop off which do not come close to what I have measured.

I've created a few Youtube videos about the filters as well:

• Aliexpress 20m Band Pass Filter
• Aliexpress 40m Band Pass Filter
• Chinese Band Pass Filter Power Tests

Jump to specific sections:

• Inside look of the 40m band pass filter
• Inside look of the 20m band pass filter
• Inside look of the 15m band pass filter
• Spectrum Sweep
• Filter specific band pass close-ups
• 80m / 3.5 MHz band close-ups
• 40m / 7 MHz band close-ups
• 20m / 14 MHz band close-ups
• 15m / 21 MHz band close-ups
• SWR sweeps

Internals of the 40m Band Pass Filter

Internals of the 20m Band Pass Filter

Internals of the 15m Band Pass Filter

Spectrum Sweep

Spectrum analyzer sweep from 1.3 MHz to 30 MHz

40m Band Pass Filter

20m Band Pass Filter

15m Band Pass Filter

Filter Specific Band Pass Closeups

Spectrum analyzer sweep of the band pass with skirts.

40m Band Pass Filter

20m Band Pass Filter

15m Band Pass Filter

80m / 3.5 MHz Band Closeups

Spectrum analyzer sweep of the 80m / 3.5 MHz band.

40m Band Pass Filter

20m Band Pass Filter

15m Band Pass Filter

40m / 7 MHz Band Closeups

Spectrum analyzer sweep of the 40m / 7 MHz band.

40m Band Pass Filter

20m Band Pass Filter

15m Band Pass Filter

20m / 14 MHz Band Closeups

Spectrum analyzer sweep of the 20m / 14 MHz band.

40m Band Pass Filter

20m Band Pass Filter

15m Band Pass Filter

15m / 21 MHz Band Closeup

Spectrum analyzer sweep of the 15m / 21 MHz band.

40m Band Pass Filter

20m Band Pass Filter

15m Band Pass Filter

SWR sweeps

SWR sweeps of the pass band.

40m Band Pass Filter

20m Band Pass Filter

15m Band Pass Filter