SDRplay Community Forum

Conrad Farlow wrote:Is the dual tuner mode guaranteed to be coherent and can I stream 2 pairs of coherent IQ data?

The dual tuners are capable of being time coherent but they are not in the present software (SDRuno v 1.24) . IQ streaming is planned for a future version. SDRplay does not give release dates for software so we will have to wait.....

Hello Roger.

Then SDRplay will have to wait for my cash

Do you know if the ExtIo allows coherent operation and whether or not the HDSDR implementation allows IQ streaming of all 4 channels?

Regards

Conrad PA5Y

Conrad Farlow wrote:Hello Roger.

Do you know if the ExtIo allows coherent operation and whether or not the HDSDR implementation allows IQ streaming of all 4 channels?

No the RSPduo Extio.dll does not support coherent support of both tuners. HDSDR does have IQ streaming but only of one tuner at a time.

Roger wrote:

Conrad Farlow wrote:Is the dual tuner mode guaranteed to be coherent and can I stream 2 pairs of coherent IQ data?

The dual tuners are capable of being time coherent but they are not in the present software (SDRuno v 1.24) . IQ streaming is planned for a future version. SDRplay does not give release dates for software so we will have to wait.....

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I am surprised. If I am reading the above correctly, the whole reason I bought the RSPduo is delayed until some, unspecified, future date. I never saw this "detail" on the SDRplay web site nor in the SDRuno manual. Rather I saw the ability to do phase coherent, diversity reception touted as a feature. I was wondering how the LO's could be different and still phase locked. I made sure the LO's were the same and locked them, but I guess I was wrong in the assumption they were phase locked. I have encouraged others to buy this receiver for coherent diversity reception, now I have to give them the happy news...

Hello Bluesheep,
There seems to be a bit of confusion here. The two tuners in the RSPduo both run off a common reference clock and so if tuned to the same frequency, both tuners will be phase locked and I/Q streams are time aligned. However, because as things currently stand, the two tuners (to operate simultaneously) have to operate in separate instances of SDRuno, then as the instances cannot be started simultaneously, buffering means that the audio for the two tuners will not be time aligned between the separate instances of SDRuno.

The solution to this will be when we release a version of SDRuno that can process both I/Q streams within a single instance and this will allow us to perform diversity and noise cancellation. This is currently scheduled for release 1.4 of SDRuno which will be the release after 1.3 which is currently in development.

We already have customers who (under Linux) have developed their own noise cancellation software using the RSPduo and our current service based API and so we know that the technology works just fine.

We cannot give a schedule for release 1.4 as there is still a lot of development work on-going for release 1.3 which includes a range of long promised features such as scanning, moving registry settings to a .INI file, piping I/Q audio to VAC etc.

I hope this clears up any confusion.

Sincerely

Tech_Support

Personally I would just like to see an ExtIO that has a mode to lock the two receivers and produce 2 coherent streams that can be used with Linrad and MAP65. There are a number of EME operators that would find this useful. This would not take as much effort as a major software release and would satisfy a need.

73

Conrad PA5Y