This modification kit applies to the KBPF3, K3 RF board, and optionally to the KRX3 sub receiver. It allows the K3 or K3S to receive signals in the 100-500 kHz range with good sensitivity.
Here are the requirements to receive signals in this range:
1. KSYN3A synthesizer. (The K3S comes with with the KSYN3A standard; it is available as an upgrade for the K3.)
2. KBPF3 filter option. This mod kit upgrades the KBPF3 to a KBPF3A, which covers the 100-500 kHz range.
3. KXV3 RF I/O module (any type). A KXV3 is needed because signals in the 100-500 kHz range can only be copied with the antenna contacted to RX ANT IN or XVTR IN. Both of these jacks are located on the KXV3. (Signals in this range are greatly attenuated when received through the normal ANT1/ANT2 path, because the T/R switch includes a 1.5-MHz high-pass filter to protect the transceivers's PIN diodes.)
NOTE ON NUMBER OF MOD KITS NEEDED (1 or 2): This mod kit can be used to upgrade one KBPF3 and either a K3 RF board or a KRX3 sub receiver. If you have two KBPF3As (one for the main receiver and one for the sub receiver), and you wish to use both for 100-500 kHz reception, then you will need two of the mod kits.
NOTE ON SURFACE-MOUNT COMPONENTS: The KBPF3 part of this modification requires the removal of two surface-mount inductors, and the addition of three 0603-sized surface-mount capacitors. Please read the instruction sheet to determine whether you have the right tools and experience to complete the mod. If not, we can perform the modifications for you for a nominal charge.