The Geosun set top box units display frequent pixelation at the signal reception threshold but the MiniTiouner-Express unit is quite stable at that point with no pixelation. But, if I reduce the signal level of either just one dB, they drop out of lock as expected. The signal level at which the cliff effect takes place on the MiniTiouner-Express hardware prototype is -94dBm reliably (when receiving a transmission with FEC=7/8 and an RF BW of 4.2 MHz), which is about 5 dB lower signal strength than when using his sensitive Geosun STB.
Figure01 – Hand-soldered prototype using MiniTiouner-Express PCB with Serit NIM. The NIM lies flat underneath the PCBA.
The MiniTiouner-Express hardware unit is designed to run with MiniTioune software developed by Jean Pierre Courjaud, F6DZP. Jean-Pierre F6DZP has been modifying Digital-ATV receivers for DVB-S protocol with software for years (and recently also DVB-S2) - in order to allow the tuner to provide information that hams need. The main problems with commercial DVB-S receivers are (a) that if the signal is not good enough - they show only the “blank screen of death” and (b) they do not work with smaller Symbol Rates that some hams want to use. The MiniTioune receiver/analyzer software from F6DZP solves these two problems. Figure02 shows a screen-capture of WA8RMC’s transmission received via the ATCO clubs DVB-S on 1268 MHz using F6DZP’s V.0.6b software. {Three NOTES:
(1) The received signal from the WR8ATV repeater is from about 15 miles away through trees.
(2) The F6DZP software v0.6b being run with MiniTiouner-Express hardware does not yet recognize this hardware unit…hence Fig02 displays “NIM = SeritPro”.
(3) Jean Pierre F6DZP reports that the next version of the 'MINITIOUNE software that he releases, v0.8a - Receiver/Analyser DVB-S/S2 144 MHz to 2450 MHz - for MiniTiouner/ MiniTiouner-Pro/ MiniTiouner-Express', will correctly recognize the MiniTiouner-Express hardware.
Figure02 – Screen-capture using F6DZP MiniTiouner v0.6d software being received from ATCO WR8ATV repeater (about 15 miles away)
WA8RMC’s intent is to produce a smaller and assembled and tested version of the Serit NIM PCBA design at an affordable price. The MiniTiouner-Express project team has decided to sell the MiniTiouner-Express hardware unit (with cover included) at US$75 plus shipping from USA (plus any applicable VAT). Art reports that he expects to robot-assemble the “first article” MiniTiouner-Express PCBA around January 05 and then begin testing.
Finally, Analog Devices appears to have delayed the next PLUTO Tx/Rx lot availability in order re-spin the PLUTO PCB. The PLUTO availability slipped out from 16 weeks…to 24 weeks ….see Figure03 from electronics distributor, Mouser USA.
Figure03 – Screen-capture from electronic distributor, Mouser USA, on latest PLUTO-SDR Tx/Rx availability.
Charles G4GUO had spotted an Analog Devices explanation of the PLUTO availability delay in the release-notes of Analog Devices which described a circuit change in the PLUTO PCB to improve the PLUTO power-supply noise.
“Project speed set to slow” …. de Ken W6HHC