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ik1xpv / ExtIO_sddc

ExtIO_sddc.dll - BreadBoard RF103 / HDSDR
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VHF background pattern #188

Closed Ploends closed 2 years ago

Ploends commented 3 years ago

The new extio file has clearly solved the problem of VHF singals in HF spectrum. Well done ! On my RX888 MKII unit I can still observe a significant amount of HF signals travelling into VHF and creating a background pattern. I have attached a few photos to explain what I observe: The first photo shows my HF spectrum at 32 MHz bandwidth. RF is set to 0 and IF is set to -25. All is fine.

Photo 1

The second photo shows the VHF spectrum, also at 32 MHz bandwidth, that I see when I tune into the FM broadcasting area. The RF in VHF is set to 0. The IF is -5. One can see some week VHF signals and a pattern of a lot of HF signals that seem to be mirrored into VHF.

Photo 2

When I tune within the VHF spectrum, the VHF signals move as expected but the background signal pattern remains the same. The signals of the background pattern do not not move.

Photo 3

On the final photo one can see that the background pattern disappears completely when I disconnect the HF antenna. Then only the VHF signals remain.

Photo 4

Not sure if this is a Bug or an issue with my MKII unit ?

ik1xpv commented 3 years ago

Many thanks for the detailed report. The today Howard's PR #187 possibly will reduce the problem. May you please made a test with the code you find here at page Actions In the bottom of page you find the compiled extio-package.zip. Thanks in advance, Oscar

Ploends commented 3 years ago

Dear Oscar, Thanks for your quick reply. Unfortunately the situation is still the same even with the Extio package from the link that you provided. Regards

Marcus

ik1xpv commented 3 years ago

Hi Marcus, Please test this code #189 In the bottom of page you find the compiled extio-package.zip. Possibly it will decrease the crosstalk by some 30 dB. BR
Oscar

Ploends commented 3 years ago

Hi Oscar, this is indeed a massive improvement ! Only the 5 strongest AM signal are still visible on the right sight of the 8 MHz VHF window. These 5 signals are the strongest AM broadcasting stations that I can receive here in Edinburgh.

Thanks

Marcus

howard0su commented 3 years ago

I will mark this as resolved unless there is objection.