always the same frequency span in sdr console

pirpy
Posts: 23
Joined: Sat Jan 28, 2023 10:45 pm

Re: always the same frequency span in sdr console

#41

Unread post by pirpy »

Hello
i had fujitsu sunrich u-550 pci-e to usb expansion card laying around and it works on first try. :)
thank you very much dk7jl

Best Regards

Pirpy

jdow
Posts: 803
Joined: Mon Aug 10, 2020 8:17 pm

Re: always the same frequency span in sdr console

#42

Unread post by jdow »

Why on Earth would you want to waste a 3.2 port on a 2.0 device that will slow the 3.2 port down to 2.0 speeds when it is on the bus. You cannot extract wider bandwidth with the higher speed USB ports.

This sounds like an AMD defect - that is not particularly important depending on the sanity of the user.

{^_^}

pirpy
Posts: 23
Joined: Sat Jan 28, 2023 10:45 pm

Re: always the same frequency span in sdr console

#43

Unread post by pirpy »

jdow wrote: Wed Apr 26, 2023 6:57 am Why on Earth would you want to waste a 3.2 port on a 2.0 device that will slow the 3.2 port down to 2.0 speeds when it is on the bus. You cannot extract wider bandwidth with the higher speed USB ports.

This sounds like an AMD defect - that is not particularly important depending on the sanity of the user.

{^_^}
What are you talking about???

gm8arv
Posts: 1
Joined: Sat May 14, 2022 6:54 am

Re: always the same frequency span in sdr console

#44

Unread post by gm8arv »

jdow wrote: Wed Apr 26, 2023 6:57 am Why on Earth would you want to waste a 3.2 port on a 2.0 device that will slow the 3.2 port down to 2.0 speeds when it is on the bus. You cannot extract wider bandwidth with the higher speed USB ports.

{^_^}
Although I have found that when running an Airspy R2 at maximum speed a USB 3 port produced less loss than a USB 2 port, on at least one system.

jdow
Posts: 803
Joined: Mon Aug 10, 2020 8:17 pm

Re: always the same frequency span in sdr console

#45

Unread post by jdow »

OK - USB 2 is "barely" adequate for I/Q at 10 Msps 16 bits per sample (4 bytes/sample). There is a (lossless) compression capability for AirSpy that combines 12 bits of I and Q into 3 bytes/sample. That still requires a relatively unused USB 2 system. So there is a reason to go to a 3.0 port. For extreme cases there is a relatively standard if expensive plugin card I recommend when it can be used, a StarTech.com PEXUSB3544V. Upon rereading - you don't really have a native choice when everything is USB 3.2 or an already in use USB 2. Normally one can pick either 3.0 (old board) or choose from some 3.1 and some 3.2 ports.

And thanks for the heads up on this AMD limitation. I had a Lenovo that had 3.0 ports - that never worked worth a damn with bulk USB 2.0 transfers. USB is not as simple as it's touted to be, I guess.

{^_^}

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