I/Q Bandwidth

Jim KJ3P

What chunk of bandwidth is represented by the I/Q output with a 6600? And is that bandwidth centered on the center frequency of the slice?

Jim KJ3P

Thanks Len!

David Decoons, wo2x

In Dax, you can set the I&Q to 48, 96 or 192 kHz. It is centered on center of panadapter display.

73

Dave wo2x

Jim KJ3P

Greatly appreciate this valuable info...thanks!

KD0RC

Hi Jim, the maximum IQ bandwidth of the 6600 is 192 kHz. I am not sure where it is centered, as multiple slices can be open in that space.

Rich McCabe

I just sent Mike a message about this and then found this post. Apparently not everyone has 192000 available. I have talked to a couple people that says theirs has a max is 96000. Any idea why?

I wish Flex would listen to feedback from developers about how the IQ is coupled to the center of the panadapter. It causes issues.

Yuri from SDC says because of this when changing bands using the band selector on the left of SmartSDR it breaks the IQ audio stream on his skimmer. Its a Flex issue he cant fix. You have to close SDC program completely and restart to make it work again. I talked to Don at Slicemaster and he has to close CWskimmer and reopen it again to get around this band switching problem. You can type a new frequency in the slice and it will switch fine but apparently when you switch bands via the band buttons the program kills the slice and creates a new one which breaks the IQ stream.

Jim KJ3P

I'm told that the 6600 can output 192 kHz of bandwidth, but that the 6300 outputs 96 kHz. Perhaps this number varies with the number of slices that can be open simultaneously on a specific model radio.

KD0RC

Hi Jim, I see now that my 6400 only goes up to 96,000 samples per second. I am guessing that this is due to the 122.88 Msps of the 6400 ADC vs the 245.76 Msps of the 6600 ADC. Maybe Flex could chime in and let us know for sure.

Rich McCabe

For what its worth it appears not all 6400s are created equal. I worked with an older 6400 yesterday that was limited to 96000 and talked to someone today with a newer one that does 192000.

Having 192000 is actually pretty nice since Flex chose to tie the center of the Panafall to the center of IQ stream. The IQ band plan control window on the SDC program is a very good example that you can be missing spots when running a skimmer when our bandplan goes outside of the IQ stream. Still does it on some bands with 192K but obviously much less than it does with 96k.