DATV Express : Help needed :-)

[on8ge]

Hello All,

I am busy to make tests in DBVT 2MHZ bw with the board but I cannot receive the stream on HIDES HV110 receiver.
All tested, last firmware flashed but no way.

I am using the 1.23 version.

Any idea ?

73's ON8GE

[G8GKQ]

Hi

I'm running DATV Express V1.23 on Win 10; video source is vMix. Receiver is a Hides UT-100D with BDA Viewer+

Pictures below of what works and what BDAViewer+ reports:

Hope that helps

Dave
G8GKQ

[on8ge]

Thanks a lot, I think I made mistake in SR rate......... I will try.

[on8ge]

Can you make screenshot of your SI Table please ?

[G8GKQ]

HI

Here's the SI Table and the system tab

Dave
G8GKQ

[G8GKQ]

BTW, TX and RX running on the same PC.

Dave

[on8ge]

Hello Dave,

I tried 4 hours with all parameters combination, no way. Signal is present, but Quality = 0.
RX used HV-110

Pierre

[g8cpf]

Hi Pierre.... some comments made recently by Phill GW8BVI on GB3ZZ chat line re use of vMix and DATV Express may be relevant.... Good luck..

[G8DKC]

Hi Pierre,

Please read some of the info here, one of Ken's updates....

http://www.batc.org.uk/forum/viewtopic. ... guo#p11391

Charles has noted that with the right USB2 chipset all is well on DVB-T, I have the same problem,

others may not.

Without buying a new machine, I am using the original Linux program running Ubuntu on a spare Pc.

It uses lower bit rates, so quality not there, but does not have the same pressure on USB2 through put.

https://datv-express.com/CustomPage/Downloads ... DATV-Express v2.03 32-bit i386 DEB or v2.03 64-bit AMD DEB.

You may know some of this but it may help others.

73

Peter

[KenW6HHC]

Hi Pierre ON8GE,

On DATV-Express for Windows, the DVB-T protocol USB-traffic has a tendency to “overload” the computer USB-bus-architecture on a slower PC and can even “overload” some newer PC’s that have a poor USB-bus-architecture design. The DVB-T USB-loading is very close to the real-world throughput limits of a USB-2 bus. Charles G4GUO who has performed much DVB-T testing with DATV-Express explains that if the DVB-T USB-traffic to the DATV-Express board can not keep up with the protocol bit-rate/symbol-rate, it creates short drop-outs in the transmission that can upset some DVB-T receivers. In the referenced posting of the 2016-12-01 “DATV-Express report”, Charles reported that “Only one of his three 64-bit computers running express_DVB_Transmitter [Windows] software would allow the UT-100B to lock on his signal.

Also, running vMix on the Windows increases the CPU loading and USB-data-traffic loading. I found that even running DVB-S protocol with vMix on my old (2009) dual-core-3GHz Dell 32-bit notebook caused drop-outs in the transmission and (if I remember correctly) would create receiver freezes every few seconds. I came to suspect that my old dual-core Dell notebook had a low-cost and NOT-high-performance USB-2 bus architecture. As G4GUO describes it, my old Dell had the "wrong USB-2 chip-set". Since I purchased a faster Dell 64-bit notebook (i7 four-core CPU at 3.10 GHz], my DVB-S/vMix drop-out issues have disappeared and I transmit 2 MHz channel-bandwidth DVB-T on Win10 without problems to my HiDes UT-100B receiver…achieving a quick LOCK and without any problems.

What is the speed of the computer that you are using? What Windows operating system are you using?

73…de Ken W6HHC