Chaining 2 KerberosSDR's

Discuss KerberosSDR - 4x Coherent RTL-SDR
CCode
Posts: 5
Joined: Wed Apr 03, 2019 2:06 pm

Chaining 2 KerberosSDR's

Post by CCode » Wed Apr 03, 2019 7:21 pm

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?

rtlsdrblog
Site Admin
Posts: 2368
Joined: Mon Nov 19, 2012 11:54 pm

Re: Chaining 2 KerberosSDR's

Post by rtlsdrblog » Thu Apr 04, 2019 12:23 am

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.

thewyliestcoyote
Posts: 1
Joined: Sat Apr 06, 2019 6:13 am

Re: Chaining 2 KerberosSDR's

Post by thewyliestcoyote » Sun Apr 07, 2019 5:51 am

How about more then 2?

rtlsdrblog
Site Admin
Posts: 2368
Joined: Mon Nov 19, 2012 11:54 pm

Re: Chaining 2 KerberosSDR's

Post by rtlsdrblog » Sun Apr 07, 2019 10:57 am

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.

CCode
Posts: 5
Joined: Wed Apr 03, 2019 2:06 pm

Re: Chaining 2 KerberosSDR's

Post by CCode » Mon Apr 29, 2019 7:08 pm

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.

rtlsdrblog
Site Admin
Posts: 2368
Joined: Mon Nov 19, 2012 11:54 pm

Re: Chaining 2 KerberosSDR's

Post by rtlsdrblog » Mon Apr 29, 2019 11:08 pm

They'll need to be connected to the same noise source too via the splitter.

CCode
Posts: 5
Joined: Wed Apr 03, 2019 2:06 pm

Re: Chaining 2 KerberosSDR's

Post by CCode » Tue Apr 30, 2019 12:21 am

Is the noise source disabled when the jumper is to set slave? Maybe to save power?

sudip
Posts: 4
Joined: Thu Apr 18, 2019 2:57 pm

Re: Chaining 2 KerberosSDR's

Post by sudip » Tue Apr 30, 2019 6:07 pm

Hello,

May I request the complete block diagram of the KSDR?

Regards,

Sudip

rtlsdrblog
Site Admin
Posts: 2368
Joined: Mon Nov 19, 2012 11:54 pm

Re: Chaining 2 KerberosSDR's

Post by rtlsdrblog » Wed May 01, 2019 5:23 am

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.

rtlsdrblog
Site Admin
Posts: 2368
Joined: Mon Nov 19, 2012 11:54 pm

Re: Chaining 2 KerberosSDR's

Post by rtlsdrblog » Wed May 01, 2019 5:25 am

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

Post Reply