Easy-Transceiver

The whole design is modular, parametric (cost and others), field repairable, and super extensible. It is almost trivial to add support for more FSK digital modes.

The Easy-Transceiver hardware works with the native Hybrid FT8 Radio Android app, and also with WSJT-X (running on RPi).

The Easy-Transceiver system can be built for around 3000 INR (~40 USD) or less. We are working on reducing the cost to 2300 INR ;)

Author 1: LU2HES - https://github.com/agustinmartino

Author 2: Dhiru Kholia (VU3CER) - https://www.qrz.com/db/VU3CER/

TX chain:

RX chain (Easy-uSDX - optionally headless):

QSO(s):

QSOs over 15000 kms were made using this HW with PA150 (with around 37W ERP).

Notes

This will need a HF RF PA in most cases to be usable on the air.

UPDATE (January 2022): Check out our cost-effective, and robust HF PA system.

Setup

• Use Python 3.10.x for maximum compatibility.

• Setup dependencies.

  pip install -r requirements.txt

T/R Switch

Check out our cost-effective, and simple T/R switch design.

BCI Filter

Are you hearing broadcast AM signals in the background of the uSDX receiver? If yes, a simple BCI filter can solve this problem easily enough.

Checkout the RX BCI Filter included in this repository.

BOM

• High Quality Female to Female Jumper Wire - 2500mA (Project Point)

• Female and male berg strip

• Arduino Nano v3 board - 450 INR - We will eliminate this requirement soon

• SN74CB3T3253DR (SOIC-16, Semikart) - ~200 INR

• Bunch of 100nF MLCC - 25 INR ('Emerging Technologies' Store -> ET)

• Bunch of 10nF MLCC - 10 INR

• Bunch of 1nF MLCC - 20 INR

• 4 x 470nF MLCC - 10 INR

• 1 x 1N5819 - 2 INR

• 1 x 1N4007 - 2 INR

• 1 x 7805 Linear Regulator - 15 INR

• 2 x 100uH inductor - 12 INR

• Si5351 Module - 470 INR (no delicate soldering required!)

  • Cheaper to get MS5351M from LCSC (in bulk for more experiments) - <= 100 INR

• Bunch of 10k resistors (MFR, ET / Project Point) - 25 INR

• Bunch of 1k resistors - 10 INR

• 1 x 1k 0.5W resistor - 5 INR

• 1 x 470 0.25W resistor - 5 INR

• 2 x 82k 0.25 resistor (MFR) - 5 INR

• 4 x 100 Ohm resistor (MFR) - 5 INR

• 1 x 3.5mm Stereo Socket ('PJ-307', https://www.electroncomponents.com/Stereo-Socket-3.5mm-connector-pcb) - 12 INR

• BCI Filter BOM - 2 x 2.2nF ceramic capacitor, 2 x 820pF (can be resistor shaped!), 3 * 2.2uH inductor axial

• 2 x SMA connectors (https://www.ktron.in/, SMA Straight - Female - Vertical Mount) - 50 INR

• ATmega328P (DIP-28) - 225 INR

• 20 MHz crystal - 10 INR

• LM4562NA - 220 INR (Semikart) OR NE5532AP (130 INR from Semikart, 30 INR locally from https://rarecomponents.com)

  The NE5532 is widely faked - even https://www.electronicscomp.com/ sells a cheap knockoff!

  TIP: Get TI make NE5532 from https://rarecomponents.com/.

• Misc: Copper clad board (glass epoxy one), Relimate male connectors + female cable, Male berg strip, Female-to-female dupont cables

  Get from https://www.electronicscomp.com/ and https://projectpoint.in/ shops.

• Total: Around 1500 to 1600 INR

BOM Sources

• https://robu.in/ (https://www.ktron.in/ has better pricing at times)

• https://www.electronicscomp.com/ (2.2uH Inductor)

• https://projectpoint.in/ (222 MLCC, 820pF MLCC)

• https://www.electroncomponents.com/2.2uh-inductor-inductance-coil (2.2uH Inductor)

Tips

Useful commands:

pacmd load-module module-null-sink sink_name=Virtual0
pacmd update-sink-proplist Virtual0 device.description=Virtual0
pacmd update-source-proplist Virtual0.monitor device.description=Virtual0

Use Gqrx and WSJT-X with a SDR device for initial frequency adjustment / calibration. This is essential for WSPR functionality. FT8 is more robust/tolerant of frequency deviations due to a much larger RX window.

References + Credits

• https://github.com/WB2CBA for the uSDX PCB

• https://github.com/kgoba/ft8_lib

• https://github.com/etherkit/JTEncode

• https://learn.adafruit.com/adafruit-si5351-clock-generator-breakout/wiring-and-test

• https://github.com/agustinmartino/wsjt_transceiver

• https://github.com/agustinmartino/wsjtx_transceiver_interface

• https://www.qrp-labs.com/synth/ms5351m.html

• https://github.com/kholia/Easy-Digital-Beacons-v1

• https://github.com/kholia/HF-Balcony-Antenna-System (fun!)

• https://github.com/kholia/SMPS-Noise-Filter