George is great.

Simon Brown

https://g4eli.com

https://sdr-radio.com

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From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> on behalf of sm6fhz via groups.io <ingolf.fhz@...>
Sent: 10 September 2022 12:52
To: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io>
Subject: Re: [SDR-Radio] Pluto specifics

 

QSL Simon.
I see, that's the limitation.
I wonder if the "internal" Ethernet port on the board (not via the USB port) would support the full 20 MHz BW or a similar limitation is there as well.

BTW how's George?

73 / Ingolf

--

- + - + -

Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.

Hi.
When I read the data for the Pluto and the heart of the Pluto, the AD9363 (alt. AD9364) I see a specified Bandwidth of maximum 20 MHz.

https://wiki.analog.com/university/tools/pluto/users/customizing#updating_to_the_ad9364

When I look at the settable Bandwidth in SDRC I see Bandwidths up to 6 MHz.
Can someone explain this. Is there a catch somewhere, I do not see.
It is only for my curiosity. Presently I do not have any use of larger Bandwidths except for using it to receive the full FM broadcast band.

73 / Ingolf, SM6FHZ

And let us not forget that Pluto is very much an educational device which we amateurs have adopted.

Beats me why people spend many thousands of euro on Kuhne transverters etc. when you can do the job for far less with a Pluto and SG Labs after blaster.

Simon Brown

https://g4eli.com

https://sdr-radio.com

---

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> on behalf of jdow via groups.io <jdow@...>
Sent: 11 September 2022 06:52
To: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io>
Subject: Re: [SDR-Radio] Pluto specifics

 

The TL:DR is "USB2".

The reason is the maximum bandwidth you can cram through a USB 2 connection. (AirSpy and AirSpy (R2) push the limits of USB 2 and sometimes get 10 MHz bandwidth without dropouts and without bitpacking. Without bitpacking 6 Msps is a better choice for reliability than trying to push it a little.

NOTE that you likely will not get 6 Msps through an Ethernet connected Pluto. 100 MHz Ethernet is a little faster than 1/4th the speed of the USB2 connection. (A USB2 to 1 G ethernet adapter would probably make it to 6 Msps. I've never seen one.)

{^_^}

On 20220910 01:30:42, sm6fhz wrote:

Hi.
When I read the data for the Pluto and the heart of the Pluto, the AD9363 (alt. AD9364) I see a specified Bandwidth of maximum 20 MHz.

https://wiki.analog.com/university/tools/pluto/users/customizing#updating_to_the_ad9364

When I look at the settable Bandwidth in SDRC I see Bandwidths up to 6 MHz.
Can someone explain this. Is there a catch somewhere, I do not see.
It is only for my curiosity. Presently I do not have any use of larger Bandwidths except for using it to receive the full FM broadcast band.

73 / Ingolf, SM6FHZ

--

- + - + -

Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.

On Sep 11, 2022, at 9:18 AM, Roy VE7DH <ve7bpb@...> wrote:

The question that occurs to me; if 6 mhz is the limit due to USB2 limitations, then why is there a 10Mhz setting when using my SDRPlay devices with USB2? In fact, I have been running one of my RSP2 units at 8 Mhz for years monitoring wspr frequencies from 160m to 40m without any difficulty using my first generation I7 computer.

regards, Roy

The question that occurs to me; if 6 mhz is the limit due to USB2 limitations, then why is there a 10Mhz setting when using my SDRPlay devices with USB2? In fact, I have been running one of my RSP2 units at 8 Mhz for years monitoring wspr frequencies from 160m to 40m without any difficulty using my first generation I7 computer.

regards, Roy

In theory a USB2 should be capable of 30 MHz. But with overhead in practice, and other real world detriments 15 MHz is more realistic. Folks that use USB hubs will see even less. Never use a hub if speed is important. Use the shortest possible quality USB cable in a direct on computer USB connector for best results. 

Larry K4LED 

_______________________

Click for K4LED Reference Links:

On Sep 11, 2022, at 9:18 AM, Roy VE7DH <ve7bpb@...> wrote:

The question that occurs to me; if 6 mhz is the limit due to USB2 limitations, then why is there a 10Mhz setting when using my SDRPlay devices with USB2? In fact, I have been running one of my RSP2 units at 8 Mhz for years monitoring wspr frequencies from 160m to 40m without any difficulty using my first generation I7 computer.

regards, Roy

480 mega bits per second gets cut down considerably to maybe as high as 400 Mbps or lower. Depending on who is doing the counting (and the hardware and software) this translates into as low as 30 MBps (unusual) and as high as 45 MBps (almost unheard of). Each sample is a pair of 2 BYTE subsamples. To make 10 Msps for I/Q samples you must have the bus pushing 40 MBps with very high reliability, I've never achieved this with no dropouts on a USB2 port - because that is where I plug in the keyboard and mouse. They take a LOT of time on the bus for very low transfer rates.

{^_^}

On 20220911 06:34:36, Larry Dodd wrote:

In theory a USB2 should be capable of 30 MHz. But with overhead in practice, and other real world detriments 15 MHz is more realistic. Folks that use USB hubs will see even less. Never use a hub if speed is important. Use the shortest possible quality USB cable in a direct on computer USB connector for best results. 

Larry K4LED 

_______________________

Click for K4LED Reference Links:

On Sep 11, 2022, at 9:18 AM, Roy VE7DH <ve7bpb@...> wrote:

The question that occurs to me; if 6 mhz is the limit due to USB2 limitations, then why is there a 10Mhz setting when using my SDRPlay devices with USB2? In fact, I have been running one of my RSP2 units at 8 Mhz for years monitoring wspr frequencies from 160m to 40m without any difficulty using my first generation I7 computer.

regards, Roy

Just do not use mouse or kbd on the same port..

Am 11.09.2022 21:16 schrieb jdow <jdow@...>:

480 mega bits per second gets cut down considerably to maybe as high as 400 Mbps or lower. Depending on who is doing the counting (and the hardware and software) this translates into as low as 30 MBps (unusual) and as high as 45 MBps (almost unheard of). Each sample is a pair of 2 BYTE subsamples. To make 10 Msps for I/Q samples you must have the bus pushing 40 MBps with very high reliability, I've never achieved this with no dropouts on a USB2 port - because that is where I plug in the keyboard and mouse. They take a LOT of time on the bus for very low transfer rates.

{^_^}

On 20220911 06:34:36, Larry Dodd wrote:

In theory a USB2 should be capable of 30 MHz. But with overhead in practice, and other real world detriments 15 MHz is more realistic. Folks that use USB hubs will see even less. Never use a hub if speed is important. Use the shortest possible quality USB cable in a direct on computer USB connector for best results. 

Larry K4LED 

_______________________

Click for K4LED Reference Links:

On Sep 11, 2022, at 9:18 AM, Roy VE7DH <ve7bpb@...> wrote:

The question that occurs to me; if 6 mhz is the limit due to USB2 limitations, then why is there a 10Mhz setting when using my SDRPlay devices with USB2? In fact, I have been running one of my RSP2 units at 8 Mhz for years monitoring wspr frequencies from 160m to 40m without any difficulty using my first generation I7 computer.

regards, Roy

I presume you mean "on the same controller."

I never tried on a multi-controller USB2 card. I went USB 3 multi-controller and met a great deal of success with one device per controller chip. (Often the USB2 handling by USB3 controllers is better than that of native USB2 controllers, in my experience.)

{^_^}

On 20220911 13:23:50, Siegfried Jackstien wrote:

Just do not use mouse or kbd on the same port..

Am 11.09.2022 21:16 schrieb jdow <jdow@...>:

480 mega bits per second gets cut down considerably to maybe as high as 400 Mbps or lower. Depending on who is doing the counting (and the hardware and software) this translates into as low as 30 MBps (unusual) and as high as 45 MBps (almost unheard of). Each sample is a pair of 2 BYTE subsamples. To make 10 Msps for I/Q samples you must have the bus pushing 40 MBps with very high reliability, I've never achieved this with no dropouts on a USB2 port - because that is where I plug in the keyboard and mouse. They take a LOT of time on the bus for very low transfer rates.

{^_^}

On 20220911 06:34:36, Larry Dodd wrote:

In theory a USB2 should be capable of 30 MHz. But with overhead in practice, and other real world detriments 15 MHz is more realistic. Folks that use USB hubs will see even less. Never use a hub if speed is important. Use the shortest possible quality USB cable in a direct on computer USB connector for best results. 

Larry K4LED 

_______________________

Click for K4LED Reference Links:

On Sep 11, 2022, at 9:18 AM, Roy VE7DH <ve7bpb@...> wrote:

The question that occurs to me; if 6 mhz is the limit due to USB2 limitations, then why is there a 10Mhz setting when using my SDRPlay devices with USB2? In fact, I have been running one of my RSP2 units at 8 Mhz for years monitoring wspr frequencies from 160m to 40m without any difficulty using my first generation I7 computer.

regards, Roy

--