K9DP QRP AM Broadcast Interference BCI Filter Male/Female BNC

In this review the K9DP QRP AM Broadcast Interference BCI Filter is evaluated for low-power HF operators who face strong AM broadcast overload. The bottom line: this compact, fully assembled Male/Female BNC filter is best for hikers, POTA and SOTA operators and owners of Xiegu and SDR rigs who need a simple inline solution to reduce front-end desensitization. The reviewer found it effective at taming nearby AM stations without adapters, easy to carry at just 3.4 in length and light enough for field work.

Key Features

• Fully assembled in the USA: Ships ready to use so you can plug it into your radio immediately without soldering or assembly delays.
• Male/Female BNC connectors: Lets you connect directly to many QRP radios without extra adapters, simplifying field setups.
• Designed for AM BCI reduction: Tailored to reduce front-end overload from AM broadcast stations on HF rigs and SDR receivers.
• Lightweight and portable: At 3.4 in and about 30 grams it is easy to pack for Parks on the Air, Summits on the Air and Field Day operations.
• Tested to 20 watts: Verified operation with SSB, CW and digital FT8 at typical QRP and modest power levels for reliable field use.
• Quality components: Uses C0G (NP0) capacitors and Micrometals toroids for stable performance and durability.

Who It's For

The K9DP BCI filter is ideal for QRP operators using Xiegu radios such as the X6100, X5105, G90 or G106, and for SDR users who experience front-end overload from strong AM broadcast stations. Its compact size and male/female BNC format make it a practical carry item for portable operators who need a plug-and-play interference mitigator.

Operators who require in-line attenuation for much higher power beyond the tested 20 watts, or those needing multi-band notch solutions for complex RFI environments, should consider alternative or additional filtering options. This unit is focused on practical, low-power use rather than lab-grade high-power filtering.

Pros & Cons

Pros

• Small, lightweight and portable, making it easy to include in any field kit.
• Direct Male/Female BNC connectivity avoids extra adapters for many QRP radios.
• Built with stable C0G capacitors and Micrometals toroids for consistent performance.
• Tested with SSB, CW and FT8 up to 20 watts, covering common QRP operation.

Cons

• Rated testing to 20 watts means operators running higher power should seek a higher-rated filter for safety.
• Single-purpose BCI filtering may not address every form of complex RFI or broad-spectrum noise.

Specifications

Connector Type	Male/Female BNC
Intended Use	AM broadcast interference (BCI) reduction for HF radios and SDRs
Length	3.4 in (86 mm)
Weight	Approx 30 grams
Tested Power	Up to 20 watts (SSB, CW, FT8)
Key Components	C0G (NP0) capacitors and Micrometals toroids
Assembly	Fully assembled and tested in the USA

Our Verdict

The K9DP QRP BCI filter is a pragmatic, well-built accessory for QRP and portable operators who need to reduce AM broadcast overload without adding bulk or adapters. Its tested performance to 20 watts and quality parts make it good value for Xiegu owners and SDR users undertaking field activations, though high-power stations should look at higher-rated options.

Frequently Asked Questions

Will this connect directly to my Xiegu radio?
Yes, the Male/Female BNC connector version is designed to plug directly into many Xiegu models without additional adapters.

What power levels can it handle?
It has been tested up to 20 watts with SSB, CW and FT8; higher continuous power is outside the stated test range.

Is it suitable for portable activations like POTA or SOTA?
Yes, the small size and 30 gram weight make it convenient for POTA, SOTA and Field Day deployments.