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Chaining 2 KerberosSDR's

Posted: Wed Apr 03, 2019 7:21 pm
by CCode
KerberosSDR can also be extended to 8x receivers by daisy chaining two boards together, so that their clocks and noise sources are connected.
https://www.rtl-sdr.com/hydrasdr-previe ... -and-more/

I understand that was written in the early stages and may have changed. Is there any information available how we might go about this?

Also is there a pinout diagram available?

Re: Chaining 2 KerberosSDR's

Posted: Thu Apr 04, 2019 12:23 am
by rtlsdrblog
This hasn't really been tested yet, so we're simply saying that the CLK and USB A port are reserved for possible future use. The demo software we made won't support more than 4 tuners at the moment anyway.

The main thing is to chain the internal clock together. There is a CLK I/O port on the PCB. Connect them together with a uFL cable, and set the jumper on the second board to SLAVE.

The USB hub chip on the board can handle up to 8 connections, so you could also try linking the two via the USB A connector. But you will need still need separate power for the second board.

Re: Chaining 2 KerberosSDR's

Posted: Sun Apr 07, 2019 5:51 am
by thewyliestcoyote
How about more then 2?

Re: Chaining 2 KerberosSDR's

Posted: Sun Apr 07, 2019 10:57 am
by rtlsdrblog
thewyliestcoyote wrote:
Sun Apr 07, 2019 5:51 am
How about more then 2?
You'd probably need an extremely powerful computer and an external clock source to try this.

Re: Chaining 2 KerberosSDR's

Posted: Mon Apr 29, 2019 7:08 pm
by CCode
Should I connect the 2 units to the same noise source for calibrating or am I able to get away with just connecting the clocks and enabling both noise sources? I noticed there is a splitter for the noise source already on the board.

Re: Chaining 2 KerberosSDR's

Posted: Mon Apr 29, 2019 11:08 pm
by rtlsdrblog
They'll need to be connected to the same noise source too via the splitter.

Re: Chaining 2 KerberosSDR's

Posted: Tue Apr 30, 2019 12:21 am
by CCode
Is the noise source disabled when the jumper is to set slave? Maybe to save power?

Re: Chaining 2 KerberosSDR's

Posted: Tue Apr 30, 2019 6:07 pm
by sudip
Hello,

May I request the complete block diagram of the KSDR?

Regards,

Sudip

Re: Chaining 2 KerberosSDR's

Posted: Wed May 01, 2019 5:23 am
by rtlsdrblog
CCode wrote:
Tue Apr 30, 2019 12:21 am
Is the noise source disabled when the jumper is to set slave? Maybe to save power?
The noise source is controlled by the GPIO pins, so it's off by default unless turned on.

Re: Chaining 2 KerberosSDR's

Posted: Wed May 01, 2019 5:25 am
by rtlsdrblog
sudip wrote:
Tue Apr 30, 2019 6:07 pm
Hello,

May I request the complete block diagram of the KSDR?

Regards,

Sudip
Sorry I don't have a visual block diagram drawn up, but it's very simple:

4x RTL-SDR on the same TCXO -> Calibration Board -> Antennas