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Starting and Stopping the Pluto

Also known as ADALM-PLUTO.
G3WDG
Posts: 15
Joined: Tue Oct 27, 2020 7:36 am

Starting and Stopping the Pluto

#1

Unread post by G3WDG »

I have just modified my Pluto for external (40MHz) reference, taking care to get the level correct. All seems to be working fine, apart from a frequency offset that I (eventually) cleared by setting the offset to zero (it had a stored value, presumably what was correct for the on-board reference oscillator).

My questions relates to starting and stopping the radio. When I stop and then restart the radio, it no longer seems to be working. Screenshots attached.

The only solution I have found is to close SDRC, unplug the Pluto from PC, plug it back in and restart SDRC.

Is this normal, or am I doing something wrong?
Attachments
after stopping and starting
after stopping and starting
running normally
running normally
Last edited by G3WDG on Thu Oct 29, 2020 9:38 am, edited 1 time in total.

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Simon G4ELI
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Re: Starting and Stopping the Pluto

#2

Unread post by Simon G4ELI »

Hi,

I also have a 40 MHz mod. The 40 MHz signal must be present and locked before the Pluto starts, I see this information in the logfile. If it doesn't start then just attach the logfile here.
Simon Brown :shock:
www.sdr-radio.com

Do not send me direct e-mail, thank-you!

G3WDG
Posts: 15
Joined: Tue Oct 27, 2020 7:36 am

Re: Starting and Stopping the Pluto

#3

Unread post by G3WDG »

Thanks Simon. Yes, the 40MHz is always present and is so before the Pluto is plugged in.
The observation is reproducible. Attached logfile of the sequence. Charlie
Attachments
SDR Console tmp.txt
(60.32 KiB) Downloaded 13 times

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Simon G4ELI
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Re: Starting and Stopping the Pluto

#4

Unread post by Simon G4ELI »

Hi, In this log it seems to work?
Simon Brown :shock:
www.sdr-radio.com

Do not send me direct e-mail, thank-you!

G3WDG
Posts: 15
Joined: Tue Oct 27, 2020 7:36 am

Re: Starting and Stopping the Pluto

#5

Unread post by G3WDG »

No, it had the same problem as identified in the above posted screenshots ie all the noise had gone, after stopping and restarting the radio. Logfile was done at the time I saw the spectrum change. Again, recovery only by closing SDRC, unplugging radio, plugging it back in (ie physically with USB connection) and restarting SDRC. This is a repeatable sequence, it it behaves this way every time.

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Simon G4ELI
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Re: Starting and Stopping the Pluto

#6

Unread post by Simon G4ELI »

OK,

My gut feeling is that this is USB power-related, can you use the second USB connector as well?

When I start I just start - nothing special. I'm guessing that the Pluto's Linux / whatever innards aren't initialising fully.

Try this:
  • Stop the radio.
  • Unplug the USB cable, wait 5 seconds.
  • Connect the USB cable.
  • Start the radio.
If the start is successful then it's something else, you could maybe try a greater 40MHz signal. FWIW I can't start my Pluto unless the Leo Bodnar unit is running and synced at 40MHz.
Simon Brown :shock:
www.sdr-radio.com

Do not send me direct e-mail, thank-you!

G3WDG
Posts: 15
Joined: Tue Oct 27, 2020 7:36 am

Re: Starting and Stopping the Pluto

#7

Unread post by G3WDG »

Yes, following that sequence worked fine. SDRC was running all the time on this occasion, and the unplug/plug in again Pluto operation meant that on restarting the radio it worked normally.

When things are in the state that the radio does not restart properly, I did check that the Pluto is still there as far as being able to look at its files with My Computer and it was OK.

Yes, I realise the importance of having the 40MHz running before power on the Pluto, and get the same as you, ie the Pluto does not start without it.

Two things to try are 1) using a USB breakout cable I made for the (now defunct) Lime where the 5V is fed from an external PSU and 2) increase 40MHz drive by a dB or so.

Regarding 2), when doing the mod for external reference input, I used a scope to check the 40MHz voltage from the external (Bodnar) source was the same as had been provided by the internal oscillator, as there have been dire warnings about having too high risking damage to the Pluto. The internal osc is still physically in place, disabled with the 1k ohm to ground method.

Will report findings.
Last edited by G3WDG on Thu Oct 29, 2020 3:11 pm, edited 1 time in total.

Jean
Posts: 67
Joined: Sat Sep 05, 2020 8:49 pm

Re: Starting and Stopping the Pluto

#8

Unread post by Jean »

G3WDG wrote:
Thu Oct 29, 2020 12:18 pm
No, it had the same problem as identified in the above posted screenshots ie all the noise had gone, after stopping and restarting the radio. Logfile was done at the time I saw the spectrum change. Again, recovery only by closing SDRC, unplugging radio, plugging it back in (ie physically with USB connection) and restarting SDRC. This is a repeatable sequence, it it behaves this way every time.
Hi,

Did you try setting the RX Gain to something different than 'manual'? I experienced issues with RX gain set to manual, however they manifest themselves somewhat different as my Pluto started with a much higher gain than selected.
Btw, I see the same error 95 in your logfile when setting RX hardwaregain that I get as well.

73 Jean DJ0VL

G3WDG
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Joined: Tue Oct 27, 2020 7:36 am

Re: Starting and Stopping the Pluto

#9

Unread post by G3WDG »

Jean - many thanks!!!!

That solved the problem. I did indeed have the gain on Manual (probably was there by default, but can't be absolutely sure about that). With any of the other three options radio starts and stops perfectly.

73 Charlie G3WDG

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Simon G4ELI
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Re: Starting and Stopping the Pluto

#10

Unread post by Simon G4ELI »

Ah,

I usually use fast attack, nice catch. Thing is, the gain isn't set until the radio is started, so it must be that the gain's being set too soon and the radio needs a while to 'warm up'.

Pity the poor programmer :( .
Simon Brown :shock:
www.sdr-radio.com

Do not send me direct e-mail, thank-you!

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