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's IF signal.

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

The schematics are in Autodesk Eagle EDA format. Check the Schematic folder.

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

The BOM (containing Digikey parts) and a few pictures are available in Design folder.

The project tracking, evolution and discussion is on QRZ Forum: A FT-991/A IF tap for Panadapter / RTL-SDR inside the radio

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).

This project is also compatible with the non-A model FT-991. The only difference is that the FT-991 signal pick-up should be between RF switches Q1088 Pin 5 and Q1102 Pin 5.

Notes:

• Board (5 samples) costed $2 in jlcpcb.com.
• The parts costs around $15 in Digi-Key.
• IF is wide open, spanning the preselector filter range. With that comes also a problem: Very strong signals might spew images through the spectrum in your SDR. Use the RTL-SDR RX gain to counteract.

Changelog:

Click Here