DATV-Express Project - September update report
Posted: Sat Oct 01, 2016 12:57 pm
Charles G4GUO has produced an “experimental release” v1.19 of the Express_DVB-S_Transmitter software for Windows operating system that adds DVB-S2 protocol and corrects the French-language-Windows problem. With assistance from Jean-Pierre F6DZP who spotted that changes for “French-friendly names” required DATV-Express software to search for “Capturer” (French) and in addition to “Capture” (English). Michael HB9DUG performed some testing on French-language-Windows and confirmed that the new Express_DVB-S_Transmitter software now worked correctly with this change.
HB9DUG screen-capture during testing of RB-DATV QSO with F9ZG/P using Express_DVB-S_Transmitter (250 KSymb/sec)
on 437 MHz over distance of 390 KM
(courtesy of Michael HB9DUG)
G4GUO made the “almost final” tweaks inside experimental V1.19 build for porting the DVB-S2 protocol code from Linux to Windows by finishing the addition of DVB-S2 anti-aliasing filters to work with the low symbol-rate settings used for RB-DATV. Having DVB-S2 with low symbol-rate settings for RB-DATV are important, because Jean-Pierre F6DZP announced at CAT16 that he had released a beta-version v0.5 software for the MiniTiouner receiver that allows receiving DVB-S2 down to a symbol-rate of 100 KSymb/sec for QPSK and 8APSK modulations. Commercial DVB-S2 receivers do not work below 1 MSymb/sec.
On Sept 29, G4GUO and Dave G8GKQ and Noel G8GTZ conducted some DVB-S2 field testing on 437 MHz. Charles had a 2-way QSO with Noel on DVB-S2 with QPSK/8PSK modulations and Dave saw/heard Charles' DVB-S2 transmissions using QPSK/8APSK/16APSK/32APSK modulations over a 40 km path.
Ken W6HHC found it very enjoyable to watch live streaming of the CAT16 technical presentations using the BATC’s improved (and EXCELLENT) internet streaming facilities. G4GUO gave a presentation on the latest Express_DVB-S_Transmitter software with DVB-S2 capabilities and also future project plans.
This menu shows that DVB-S2 protocol provides many more
robust FEC settings than DVB-S (at least for QPSK modulation).
Concerning future plans for DATV-Express project, “the bad news” is Charles G4GUO explained during the presentation that the DATV-Express product is reaching end-of-life. Sales have slowed down. We are currently out of board inventory in UK and the US inventory has dropped down to three more boards. The project team has made the difficult decision that when the remaining boards are gone…sales will stop. “The good news” is that a TX/RX SDR board is expected to become available from Lime Microsystems by the end of 2016. G4GUO believes it will be possible to port the Express_Transmitter Windows code over to the LimeSDR board.
https://www.crowdsupply.com/lime-micro/limesdr
But, porting code is a full software project and a full manual project and will take some time. The hardware cost of LimeSDR board, with high speed USB-3 capability and a much bigger Altera FPGA, appears quite reasonably priced at around US$280 for TX and RX DATV capabilities.
The LimeSDR board from Lime MicroSystems can run both TX and RX
from 100 KHz to 3.8 GHz with a high-speed USB3 interface
Charles G4GUO plans to chase down the last-known problem in the experimental V1.19 build and then release a “beta version” of software for Windows software with the new capabilities. Once the new software is released, Ken W6HHC plans to post the new software on the DATV-Express web site and to then begin adding DVB-S2 into a Users Guide for Windows update.
"Project speed set to slow" ...de Ken W6HHC
HB9DUG screen-capture during testing of RB-DATV QSO with F9ZG/P using Express_DVB-S_Transmitter (250 KSymb/sec)
on 437 MHz over distance of 390 KM
(courtesy of Michael HB9DUG)
G4GUO made the “almost final” tweaks inside experimental V1.19 build for porting the DVB-S2 protocol code from Linux to Windows by finishing the addition of DVB-S2 anti-aliasing filters to work with the low symbol-rate settings used for RB-DATV. Having DVB-S2 with low symbol-rate settings for RB-DATV are important, because Jean-Pierre F6DZP announced at CAT16 that he had released a beta-version v0.5 software for the MiniTiouner receiver that allows receiving DVB-S2 down to a symbol-rate of 100 KSymb/sec for QPSK and 8APSK modulations. Commercial DVB-S2 receivers do not work below 1 MSymb/sec.
On Sept 29, G4GUO and Dave G8GKQ and Noel G8GTZ conducted some DVB-S2 field testing on 437 MHz. Charles had a 2-way QSO with Noel on DVB-S2 with QPSK/8PSK modulations and Dave saw/heard Charles' DVB-S2 transmissions using QPSK/8APSK/16APSK/32APSK modulations over a 40 km path.
Ken W6HHC found it very enjoyable to watch live streaming of the CAT16 technical presentations using the BATC’s improved (and EXCELLENT) internet streaming facilities. G4GUO gave a presentation on the latest Express_DVB-S_Transmitter software with DVB-S2 capabilities and also future project plans.
This menu shows that DVB-S2 protocol provides many more
robust FEC settings than DVB-S (at least for QPSK modulation).
Concerning future plans for DATV-Express project, “the bad news” is Charles G4GUO explained during the presentation that the DATV-Express product is reaching end-of-life. Sales have slowed down. We are currently out of board inventory in UK and the US inventory has dropped down to three more boards. The project team has made the difficult decision that when the remaining boards are gone…sales will stop. “The good news” is that a TX/RX SDR board is expected to become available from Lime Microsystems by the end of 2016. G4GUO believes it will be possible to port the Express_Transmitter Windows code over to the LimeSDR board.
https://www.crowdsupply.com/lime-micro/limesdr
But, porting code is a full software project and a full manual project and will take some time. The hardware cost of LimeSDR board, with high speed USB-3 capability and a much bigger Altera FPGA, appears quite reasonably priced at around US$280 for TX and RX DATV capabilities.
The LimeSDR board from Lime MicroSystems can run both TX and RX
from 100 KHz to 3.8 GHz with a high-speed USB3 interface
Charles G4GUO plans to chase down the last-known problem in the experimental V1.19 build and then release a “beta version” of software for Windows software with the new capabilities. Once the new software is released, Ken W6HHC plans to post the new software on the DATV-Express web site and to then begin adding DVB-S2 into a Users Guide for Windows update.
"Project speed set to slow" ...de Ken W6HHC