T41-2 Software Defined Transceiver Modules

The T41-2 Software Defined Transceiver is a derivative of the original T41-EP which was designed by Al Peters and Jack Purdum. They wrote a book, which is available from Amazon:

https://www.amazon.com/Digital-Signal-Processing-Software-Defined/dp/B0F5BDQZW3

The original T41 transceiver was designed with small “modules” which are assembled into a working amateur radio transceiver. T41-2 continues with modular design and incorporates design changes to improve ease of construction and technical performance.

Note that the T41-2 modules can be used with the original V10/V11 modules and also the 4SQRP kit. However, modifications to the Main Board are required. The modifications are described in the detail sections for the individual modules (below).

T41-2 is composed of the following modules:

1. Power Supply. This module takes the primary supply voltage and outputs 3.3 and 5.0 volts.
2. Main Board. This the DSP computation and data converter board. Several modules plug into it.
3. QSD2. This is the receiver front-end board. It does not include receiver selectivity, and it can receive from approximately 3 to 30MHz.
4. QSE2. This is the transmitter exciter. This broadband exciter can work from approximately 3 to 30MHz. It is capable of CW and SSB modulations.
5. QSE Filter. This is a 5-band low-pass-filter which is inserted between QSE2 and the input of the RF power amplifier.
6. Transmitter Low Pass Filter. This is a 5-band low-pass-filter which is inserted in both the receiver and transmitter paths via relays.
7. Low Power Amplifier. This is the driver stage for the Power Amplifier.
8. Power Amplifier. This RF amplifier has an output power of approximately 10 watts.

In addition to the above unique modules, the following commercially available modules are inserted into the system. These modules plug into the Main Board:

1. Teensy 4.1
2. Audio Adapter
3. PCM1808 ADC Module
4. PCM5102 DAC Module

There are 2 modules external to the Main Board:

5. Si5351 Module. This module is used in combination with the QSD2 and QSE2, both electrically and structurally.
6. Audio Amplifier. Other amplifier modules can be used. This amplifier has a disable/enable control. This device has been tested successfully.

There are also numerous power and RF cables and connectors required. These are similar to the original T41 described in the book.

The case can be 3D printed, or you can use some other enclosure of your own design. 3D printer example files are here:

3D printer files for the case

There is a special 3D printed bracket which creates a “super module” composed of the Si5341, the QSD2, and the QSE2. Since this is an important component of the T41-2, it is included in the detailed module descriptions below.

A Note of Caution

The information provided here and on Github sites is provided for informational purposes only. This is done in the grand tradition of amateur radio “homebrewing”. This is considered an advanced project, and it requires several skills to complete a working radio successfully. There is no warranty and no guarantees provided, so read and study carefully and proceed with caution.

Links to Details for T41-2 Modules