Buffered IF tap board for Panadapter / SDR in a Yaesu FT-991-A

Instructions, tests, pictures and full documentation: Check the Wiki

Yaesu FT-991/A Custom Panoramic Adapter Buffered TAP Board for external SDR / Spectrum Analyser

This project is a remix of OE2DOR's perfect and neatly crafted FT-991/A Panadapter board with a high impedance IF tap, in order to disturb to a minimum the radio sensitivity.

This design is compatible with both A and non-A FT-991 transceivers.

The objective is to actually lodge a RTL-SDR inside a FT-991/A, with no extra cables coming off the radio.

The schematics are in Autodesk Eagle EDA format. Check the Schematic folder. The Design folder contains the ready to print Gerber files, images and some ancillary material.

The project genesis and some discussion are logged on QRZ Forum: A FT-991/A IF tap for Panadapter / RTL-SDR inside the radio. If you need to ask questions, either file a Github Issue (preferred) or use the QRZ Forum.

If you are interested in build your own, click here to download the Gerber and order in your favourite PCB Fab (like JLCPCB, super cheap, good quality and $0 shipping on first order). Ensure to read the Wiki.

Notes:

• The board (5 samples) costed $2 in jlcpcb.com.
• The parts costs around $20 in Digi-Key.
• The IF signal is wide open, spanning the radio's preselector filter range. With that comes also a problem: Very strong signals in passband might spew images through the spectrum in your SDR. Use the RTL-SDR RX gain to counteract.
• There's a Full Version with some extra bells and whistles (more details in the Wiki). Use the Branch "Rev-R-Full".

Changelog:

Check Here