1. Add an audio amplifier to solve the problem of extremely low volume of SSB single sideband, and the effect is obvious. Redesign FM and HF bandpass filters, 2. An ESD tube is added to the input terminal for electrostatic protection and strong signal protection when transmitting in the UV section of dual antennas. 3. Use FPC soft board, the board thickness is 0.12mm, safe and reliable without short circuit, and the installation does not support the speaker. 4. Use high-quality high-frequency wire-wound chip inductors with high Q value, small internal resistance, and strong filtering selectivity. 5. In the dual-antenna solution, an additional level of band-pass filtering is added to the antenna input end, and a feeder and SMA head are used to an HF antenna from the LED, which does not affect the UV performance of the machine. The FPC soft board uses a double-sided disk, which is easier to connect to the machine. It is suitable for K5/ K6 to install S14732 soft board FPC and modify HF Shortwave full-band reception/single sideband reception. It is Suitable for single antenna and dual Antenna. Applicable models:For uv k5/k6 Due to different batches, there may be differences in product appearance, color, and printed text, which not affect the use Colour:Orange Yellow Material:PCB Package Contents: 1 set x Kit 1x 2M Expansion Chip 1x USB Programming Cable Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.