520 KHz Diplexer Filter

This high-quality PCB diplexer module comes fully assembled, tested and tuned at 520 kHz, offering exceptional performance for VLF/LF signal separation.

Key features:
9-pole Low Pass Filter: Cleanly passes signals below 520kHz with minimal loss. Output via SMA connector – ideal for sound card SDRs, analog receivers or upconverters.
9-pole High Pass Filter: Smoothly terminates signals above 520 kHz using a 50-ohm load (2×100Ω resistors in parallel), isolating the VLF/LF spectrum.
Flexible Antenna Input: Connect any external antenna to the shared diplexer input for precise band-splitting and clean signal output.
Gas Discharge Protection: RF input is protected by a 57V gas plasma tube, ensuring long-term durability and stable operation.
Optional Impedance Matching: The PCB 9ncludes a footprint (T1) for an optional 16:1 transformer for high-Z input configurations.