MiniTiouner hardware Version 2
The Minitiouner hardware is designed for easy home construction, uses only leaded components and consists of the 3 main components.
Whilst the project has previously used several tuner types and a version 1 PCB and adapter cards, new builders should only use the version 2 PCB described on this page and the Serit tuner described here.
If you already have version 1 MiniTiouner, then you probably don't need one unless you want a smaller board. (NOTE:The version 2 PCB ONLY takes the Serit tuner and you may be better off with the Serit adapter board).
To build the unit you only need to buy the following and then download the free MiniTioune software.
- The USB interface is available ready programmed from the MiniTiouner category in the BATC shop.
- The version 2 main PCB is available from the MiniTiouner category in the BATC shop.
- The Serit tuner or NIM covering 143 - 2450 MHz is available from the MiniTiouner category in the BATC shop.
- The unit uses an adjustable MCP1826 as the 1v regulator, which can be hard to find and is available from the MiniTiouner category in the BATC shop.
All other components such as Rs, Cs and 5v buck regulator are available from normal suppliers - see the parts list further down this page.
NOTE - due to different pinouts the previously available Sharp and Eardetek NIMs will NOT work with this board
Building the Version 2 MiniTiouner PCB
The PCB has been developed to fit snuggly inside a Hammond 1455 series 103x120x53mm enclosure and uses standard leaded components so no specialist techniques needed.
Setting up the hardware
The design uses a switched DC to DC converter to reduce the 12v input to 4v and thereby reduce the amount of generated heat - this is then followed by 3 linear regulators to ensure noise free voltage rails for maximum RF performance.
There is not much to set up but before connecting the DC-DC converter to the input of the linear regulators, the output MUST be set to 3.7-4v output. This is because these LDO regulators can only handle a maximum of 6V input. There is a zener to provide some protection but damage is still possible and worst case you could end up with whatever is on the input appearing at the output - i.e. 5.6V on the 3.3V and 1.2V rails.
There are two options, one is to set the correct converter voltage before its installed on the PCB. The other is to remember not to fit the jumper JP2, ALT 4V that connects it to the regulators and set it up in commissioning.
We recommend that you build and then test all the voltage rails BEFORE fitting the NIM. This is easy as you can probe the top of the RFCs.
If you don't use the DC-DC converter and run directly off an external 5V (DO NOT connect a higher voltage) supply to JP2, you may need to heatsink the regulators. With the DC-DC converter, the copper area on the board seems to be adequate as a heatsink.
Parts list and schematic
The parts list and schematic can be downloaded here:
Note the electrolytic capacitors are High ESR types chosen to minimise oscillation from the linear regulators - substitute at your peril!
The blank PCB, tuner, USB module and 1 volt regulator are available from the BATC shop
Testing and using the MiniTiouner for the first time
Once you are satisfied the voltage levels are correct and there is no smoke you need to run the MiniTioune software.
Full details including how to set up the software, drivers and decoders is on the MiniTioune software page.
On the air
Apart from the the version 1 PCB with adaptor card, this version 2 PCB with Serit tuner is the only available solution to receive and decode DVB-S2 reduced bandwidth modes - this picture shows G0MJW receiving G8GTZ/P 1920*1080 HD pictures on 146 MHz using 32 APSK (approximately 1.3 mbit/s in 550 KHz bandwidth).
