Knucker
The Knucker project is to develop a variable bandwidth DVB-T USB receiver and transmitter for use on the lower VHF bands and HF. It will also have applications for mobile stations on 437MHz and above.
Why Knucker
Why not?
Knucker is a dialect word for a kind of water dragon, living in knuckerholes in Sussex and Charles, the lead developer, also lives in Sussex....
https://en.wikipedia.org/wiki/Knucker
Timescales
December 2020 - Currently the project is at the design phase with a proof of concept receiver working on bread board hardware.
Receiver
Hardware
Charles G4GUO and the Knucker team have developed a variable bandwidth DVB-T receiver with USB interface around the Serit 4762 NIM / tuner.
Draft specifications are 100KHz to 2MHz wide OFDM, frequency range 44 to 1002MHz
Note: the 4762 NIM is capable of DVB-T and DVB-S but the DVB-S is NOT (repeat NOT) supported in any BATC applications due to restricted frequency range and low SR capability.
The PCB design by Mike G0MJW is based on the MiniTiouner Version 2 board - the photo shows the first built and tested prototype .
Version 2
This was the first protype release and BOM and schematics are available here: File:Knucker.xlsx
Version 3
First general release PCB:
Schematic is here: File:Knucker schematic V3.pdf
BOM is here File:knucker BOM V3.xlsx
USB Module
The USB module will require reprogramming with this xml file using the FTDI program called FT prog - the standard MiniTiouner USB module from the BATC will not work but can be re-programmed.
Full instructions on how to program the unit are here: http://www.vivadatv.org/viewtopic.php?f=80&t=379
Software
It is intended to develop a core Linux DVB-T receiver application that will be integrated into the LongMynd receiver core.
It is planned that the Portsdown DATV system will be enhanced to include the DVB-T receiver.
It is envisaged that a set-top box version of the code will be developed using the RydePlayer and would be known as the Knucker receiver.
Transmit
DATVexpress
Charles G4GUO is currently developing a variable bandwidth OFDM version of the DATVexpress software. This will work with the DATVExpress card, Pluto and Lime SDR.
Beta testing
We will be looking for technically competent people to help test the system in it's intended applications - low band VHF, HF and mobile.
Send us an email if you are interested in helping.
Applications
DX!!
DVB-T can be used in environments where phase distortion and multi-pathing means DVB-S does not work. Typical applications include mobile video transmissions and bands below 70MHz :-)