Multiple receivers at same time

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DaveB
Posts: 78
Joined: Sat Sep 05, 2020 10:32 am

Re: Multiple receivers at same time

#11

Unread post by DaveB »

PD3LK wrote: Sat Feb 27, 2021 9:58 pm I tried that with the SDRplay, making a Child but the max bandwidth between both instances becomes a lot smaller then.
Display 20m and 40m bands is fine when using the Matrix and 2 receivers. (SDRplay @ 10Mhz width)
You need to be aware that if you run the SDRPlay receiver at 10 MHz the ADC resolution is only 8 bits.
For info the SDR1A has 14 bit ADC at 6 MHz or smaller sample rate, 12 bit for 8 MHz, and 10 bit for 9 MHz sample rate. The older RSP1 was only a maximum of 12 bits.

In terms of usable bandwidth the SDRPlay at 8MHz is around 6.8 MHz (+/-3.4), at 9 MHz is about 7.8 MHz (+/- 3.9). When the sample rate is increased to 10 MHz the signal becomes a lot noisier and the gain needs to be turned up to bring the noise bck down again. The usable bandwith at 10 MHz is about 8.2 MHz.

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PD3LK
Posts: 517
Joined: Thu Aug 06, 2020 10:36 am

Re: Multiple receivers at same time

#12

Unread post by PD3LK »

Hi, yes i'm aware of that but i don't think that's the issue here, i'm talking about a second SDRC instance as a Child process (by the CHILD button).
Btw the RSP2pro can show a full 10 Mhz iin SDRC.

To show what i saw,
- Start both instances with a max zoom-out, so showing 6 - 16 Mhz
- Tune the Main Instance to, say, 7 Mhz and tune the Child to, say, 14 Mhz.

- Then zoom-in in the main instance to show the complete 40m band (auto center is on). See the left part of the print screen.
- As you will notice, the Child will also zoom-in on the 40m band but the VFO stays on 14 Mhz.

Tune the Child VFO back to 14 Mhz, as you will notice, arround 12 Mhz the FFT and WF signals are not seen anymore (right part of the printscreen)

Just an observation, i'm sure it can be explained. If it's a bug then i'll replace this post to the right spot.
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Reduced BW with Child.jpg

jdow
Posts: 800
Joined: Mon Aug 10, 2020 8:17 pm

Re: Multiple receivers at same time

#13

Unread post by jdow »

That indeed sounds like a bug and I suspect I know how it happened. It is a bit painful to prevent unless you handle it from the beginning in the design process. It bit me when I was building a debug tool for my partner, Loren. When it hit me that I have to reference back to the RIGHT CMainFrame ....

{o.o}

Moriarty
Posts: 4
Joined: Thu Feb 25, 2021 10:35 pm

Re: Multiple receivers at same time

#14

Unread post by Moriarty »

Hello

I have found the solution to my initial question.
Just choose "no radio" on the wjstx program. You dont have cat control , but you can put manualy the frecuency
Now i can run multiple receiver on sdrconsole and multiple wsjtx instances to study signals

The problem now is that sdrconsole uses too much procesor on the PC if i run 16 mhz, and become unusable with 32 mhz at multiple receivers´.
My computer is an intel i7 -8700 @ 3.20ghz
SDRUNO runs much less procesor at 10 mhz bandwith. I can run at least 6 receivers and 6 instances of wjstx at the same time.

This has no solution.

Regards

Max
Posts: 859
Joined: Thu Aug 13, 2020 9:47 am

Re: Multiple receivers at same time

#15

Unread post by Max »

Moriarty wrote: Mon Mar 15, 2021 10:52 pm The problem now is that sdrconsole uses too much procesor on the PC if i run 16 mhz, and become unusable with 32 mhz at multiple receivers´.
My computer is an intel i7 -8700 @ 3.20ghz
SDRUNO runs much less procesor at 10 mhz bandwith. I can run at least 6 receivers and 6 instances of wjstx at the same time.

This has no solution.

Regards
Not comparing like with like exactly, as 16 MHz bandwidth is a bigger demand of the PC than 10 MHz is it not, and 32 MHz much more so.

How does SDRC compare with SDR Uno for resources used at the same bandwidth of 10 MHz with the same SDR Play receiver? You are not running the same hardware (SDR Play versus RX888) so that could make a large difference could it not?

What graphics card do you have installed on the PC?

Max

PA3BTS
Posts: 28
Joined: Sat Aug 08, 2020 3:02 pm

Re: Multiple receivers at same time

#16

Unread post by PA3BTS »

Hi all,

Reading this topic with interest.
The problem of too much software running at the same time and interacting, pushing the processor and memory to the limit, is screaming for a solution.
One could be to pipe audio to other computer(s) in a local network, this is possible with IP-Sound, so decoding can be done remotely. I have some experience with this software, but did not test it for multiple audio sources.

Best regards,

Cornel
PA3BTS
Moriarty wrote: Mon Mar 15, 2021 10:52 pm Now i can run multiple receiver on sdrconsole and multiple wsjtx instances to study signals

The problem now is that sdrconsole uses too much procesor on the PC if i run 16 mhz, and become unusable with 32 mhz at multiple receivers´.
My computer is an intel i7 -8700 @ 3.20ghz
SDRUNO runs much less procesor at 10 mhz bandwith. I can run at least 6 receivers and 6 instances of wjstx at the same time.

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