BP-1A 3 to 30MHz continuous Variable Filter

The BP-1A kit is a 3 to 30MHz continuous bandpass filter. It is intended to improve the front stage in analog receivers or SDR (software defined receivers), experiments in radio laboratories, measuring instruments etc. where a filter is required to select any frequency segment within of 3 to 30 MHz range. In particular, medium and low cost SDR receivers need bandpass filters when receiving HF (OC) radio signals.

The BP-1A allows you to tune and select the frequencies of any amateur radio or HF broadcasting band. The tuning is done manually with a potentiometer that allows to be located at any point in the coverage range. The BP-1A incorporates three relay-switched bandpass filters covering from 3 to 6MHz, 6 to 12MHz and 12 to 30MHz.

  • Band Pass filter from 3 to 30Mhz continuos with manual tune.
  • Three tuning ranges: from 3 to 6MHz, 6 to 12MHz and 12 to 30MHz.
  • Manual control via potentiometer.
  • Dual LC filter for each margin composed of toroids and varactors.
  • Suitable for analog or software-defined receivers (SDR), HF instrumentation, RF experiments in laboratories, etc.
  • Input and Output impedance: 50 ohms. Attenuation on center pass frequency about 3dB   
  • Power supply: 10 -14V
  • PCB dimensions: 70 x 70 mm
  • All parts KIT

Nice video from F6CRP  https://www.youtube.com/watch?v=8A-0swuuzkc

Download manual

40,00 €

  • 0,12 kg
  • Out of stock

The BP-1A Variable Filter kit is retired.

However, you can freely build it yourself

I share the file to make the PCB (Sprint Layout 6.0). Download.

You will need to have the Sprint Layout viewer. Download.

BP-1A kit assembly manual (schematics, parts list etc). Download.


BOX for BP-1A

BOX enclosure for BP-1A. Included: Knob, switch, connectors, wire and screws.

23,00 €

  • 0,15 kg
  • Out of stock