Pluto:: Spurious Emissions
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Simon Brown
[Forwarded from direct e-mail]
The issue: SDRconsole produces spurious transmissions with the Pluto, abt +/- 0.5MHz and +/- 1MHz, other softwares like the "Langstone Project" and the "AMSAT_DL QO-100 TRX" do not.
I love to use your software on the QO-100 and I will do so in the future, but I have to be aware of the fact that I violate the international rules for Amateur Radio Operators regarding allowed spurious transmissions.
All the best for the New Year and mni tnx for providing us SDRconsole for free!
73 de HB9DON, Lorenzo -- - + - + -
Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.
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Simon Brown
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From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Simon Brown
Sent: 17 January 2022 06:51 To: SDR-Radio@groups.io Subject: [SDR-Radio] Pluto:: Spurious Emissions
[Forwarded from direct e-mail]
The issue: SDRconsole produces spurious transmissions with the Pluto, abt +/- 0.5MHz and +/- 1MHz, other softwares like the "Langstone Project" and the "AMSAT_DL QO-100 TRX" do not.
I love to use your software on the QO-100 and I will do so in the future, but I have to be aware of the fact that I violate the international rules for Amateur Radio Operators regarding allowed spurious transmissions.
All the best for the New Year and mni tnx for providing us SDRconsole for free!
73 de HB9DON, Lorenzo
- + - + - Please use https://forum.sdr-radio.com:4499/ when posting questions or problems. -- - + - + -
Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.
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Simon Brown
So,
Looking at logfiles it may be that the TX FIR filter is not being applied, am now working on this.
Simon Brown, G4ELI
From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Simon Brown
Sent: 17 January 2022 06:53 To: main@SDR-Radio.groups.io; SDR-Radio@groups.io Subject: Re: [SDR-Radio] Pluto:: Spurious Emissions
So,
Sigi – any comments? I’m now looking at this.
Simon Brown, G4ELI
From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Simon Brown
[Forwarded from direct e-mail]
The issue: SDRconsole produces spurious transmissions with the Pluto, abt +/- 0.5MHz and +/- 1MHz, other softwares like the "Langstone Project" and the "AMSAT_DL QO-100 TRX" do not.
I love to use your software on the QO-100 and I will do so in the future, but I have to be aware of the fact that I violate the international rules for Amateur Radio Operators regarding allowed spurious transmissions.
All the best for the New Year and mni tnx for providing us SDRconsole for free!
73 de HB9DON, Lorenzo
- + - + - Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.
- + - + - Please use https://forum.sdr-radio.com:4499/ when posting questions or problems. -- - + - + -
Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.
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Siegfried Jackstien
the pluto does not produce +/- 500 kc or 1 megs spurii ... there ARE spurious emissions ... but they are at least 40 to 42 db below main signal with FULL POWER of the pluto and they are in minimum 52 to 54 db below main signal if you keep the plutos power at around -10 dbm (and add an lna behind the pluto) i measured about a dozen plutos (all my modded plutos get a test before sending them out and a few were also tested how much spurious signals they send out) so to be in fcc rules you should keep the power of the pluto low ... then it is safe to use :-) (if you want 60 db surpression then use -20dbm or lower ... add a
20 db lna to have again the 0dbm that you had before on near full
power) how much distance (in frequency not level) the spurious emissions
are ... depends on on what frequency you are txing (the spurii are
more or less mixing products) how much level they are depends on how much power you use, on what frequency and how exact the iq correction did work ... a stable clock helps for a better exact iq correction (imagine the frequency of the main clock changes just a tiny bit WHILE doing the calibration routine!!) the chips differ a few db ... but just a tiny bit (result after iq calibration is sometimes 40 and sometimes 42 db in fullpower) a restart of a good warmed up pluto makes another iq calibration that then shows better results in that calibration (and so lower spurious levels) dg9bfc sigi ps plusminus 500kc and 1 meg?? i never have seen that!! ... do you use "tx boost" ?!? (that makes things worse and its NOT needed!!)
Am 17.01.2022 um 07:53 schrieb Simon
Brown:
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Siegfried Jackstien
just made a quick and dirty test ... set rx to 10489.700 and let
it there (switched of "sync") then sent a tune tone 500 kc higher and 1000kc higher (nothing could be seen on transponder!!) the did the same downwards (yes i know i was txing outside band!!) if there would be spurious signal plus minus 500 kc or 1000 kc i sure would have seen them (i was txing with 20w in a sixfooter!!) so ... i think its a different thing he sees on his station ...
the pluto is clean (normally) so lets ask some questions ... any switcher used to power a predriver?? (switching psu frequency may mix up with the real frequency) or is it possible that you used an external reference on your pluto that is not clean (that also may cause unwanted signals) tx boost engaged?? no ... do not used it!! ... using higher power of the pluto sends out higher spurious signals so using tx boost does not clean up your signal better use lower power setting (drive 80 to 90 maximum) and add
an lna dg9bfc sigi Am 17.01.2022 um 08:39 schrieb Simon
Brown:
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Simon Brown
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From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Siegfried Jackstien
Sent: 17 January 2022 09:58 To: main@SDR-Radio.groups.io Subject: Re: [SDR-Radio] Pluto:: Spurious Emissions
just made a quick and dirty test ... set rx to 10489.700 and let it there (switched of "sync") then sent a tune tone 500 kc higher and 1000kc higher (nothing could be seen on transponder!!) the did the same downwards (yes i know i was txing outside band!!) if there would be spurious signal plus minus 500 kc or 1000 kc i sure would have seen them (i was txing with 20w in a sixfooter!!) so ... i think its a different thing he sees on his station ... the pluto is clean (normally) so lets ask some questions ... any switcher used to power a predriver?? (switching psu frequency may mix up with the real frequency) or is it possible that you used an external reference on your pluto that is not clean (that also may cause unwanted signals) tx boost engaged?? no ... do not used it!! ... using higher power of the pluto sends out higher spurious signals so using tx boost does not clean up your signal better use lower power setting (drive 80 to 90 maximum) and add an lna dg9bfc sigi Am 17.01.2022 um 08:39 schrieb Simon Brown:
-- - + - + -
Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.
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Simon Brown
And,
Fixed but I do see a couple of other issues to look at later today.
Simon Brown, G4ELI
From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Simon Brown
Sent: 17 January 2022 10:30 To: main@SDR-Radio.groups.io Subject: Re: [SDR-Radio] Pluto:: Spurious Emissions
Sigi,
There’s a bug in my code…
Simon Brown, G4ELI
From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Siegfried Jackstien
just made a quick and dirty test ... set rx to 10489.700 and let it there (switched of "sync") then sent a tune tone 500 kc higher and 1000kc higher (nothing could be seen on transponder!!) the did the same downwards (yes i know i was txing outside band!!) if there would be spurious signal plus minus 500 kc or 1000 kc i sure would have seen them (i was txing with 20w in a sixfooter!!) so ... i think its a different thing he sees on his station ... the pluto is clean (normally) so lets ask some questions ... any switcher used to power a predriver?? (switching psu frequency may mix up with the real frequency) or is it possible that you used an external reference on your pluto that is not clean (that also may cause unwanted signals) tx boost engaged?? no ... do not used it!! ... using higher power of the pluto sends out higher spurious signals so using tx boost does not clean up your signal better use lower power setting (drive 80 to 90 maximum) and add an lna dg9bfc sigi Am 17.01.2022 um 08:39 schrieb Simon Brown:
- + - + - Please use https://forum.sdr-radio.com:4499/ when posting questions or problems. -- - + - + -
Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.
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Siegfried Jackstien
Hmm.. I see another small bug...after a bit of usage the tx buffers get a tiny bit mixed (audio is garbelled.. Sounds rough) Stop start solves it Dg9bfc sigi Am 17.01.2022 14:13 schrieb Simon Brown <simon@...>:
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Siegfried Jackstien
cant wait to have the next version to try :-) dg9bfc sigi Am 17.01.2022 um 14:13 schrieb Simon
Brown:
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Simon Brown
Hi,
Juts looks like one bug fixed but for some reason it no longer transmits at 2.1 MHz and above :( . May take some time to find this, annoying!
The bug I fixed – the TX FIR filter may not have been applied…
Simon Brown, G4ELI
From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Siegfried Jackstien
Sent: 17 January 2022 18:49 To: main@SDR-Radio.groups.io Subject: Re: [SDR-Radio] Pluto:: Spurious Emissions
cant wait to have the next version to try :-) dg9bfc sigi Am 17.01.2022 um 14:13 schrieb Simon Brown:
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Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.
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Jacques RAMBAUD
Hello Simon and all,
Using now the SDR Console v3.1 build 2496 and still have the same RF spurious as before out of my Pluto , see attached picture. Is it normal ? 73 jacques F6BKI
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Simon Brown
Hi,
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You MUST add a proper screenshot of Console, I have no idea what settings you are using. Simon Brown, G4ELI https://www.sdr-radio.com
-----Original Message-----
From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Jacques RAMBAUD Sent: 27 January 2022 10:58 To: main@SDR-Radio.groups.io Subject: Re: [SDR-Radio] Pluto:: Spurious Emissions Hello Simon and all, Using now the SDR Console v3.1 build 2496 and still have the same RF spurious as before out of my Pluto , see attached picture. Is it normal ? 73 jacques F6BKI -- - + - + - Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.
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Ken Sejkora
Hello Jacques,
Based on the image, it look as though you are using an external spectrum analyzer to measure an RF emission *FROM* your Pluto. I wouldn't think that SDR Console would be the cause of that spurious emission, but rather it is originating in the Pluto hardware itself. Does the emission still exist even when the Pluto is not being 'operated' by SDR Console, that is, with SDRC not activated? Is the emission still present if operating the Pluto with SDR software *other* than SDRC? I would suspect the spurious emission is being generated by the Pluto itself, and has nothing to do with SDRC. Just my guess anyway. I hope it helps. Good luck and 73 Ken -- WBØOCV
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Jacques RAMBAUD
Hi Simon,
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Here is the screen shot 73 jacques F6BKI
Le 27/01/2022 à 11:17, Simon Brown a écrit :
Hi,
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Simon Brown
OK,
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May I have a screenshot taken while generating the signal shown in the spectrum analyser please. Simon Brown, G4ELI https://www.sdr-radio.com
-----Original Message-----
From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Jacques RAMBAUD Sent: 27 January 2022 11:38 To: main@SDR-Radio.groups.io Subject: Re: [SDR-Radio] Pluto:: Spurious Emissions Hi Simon, Here is the screen shot 73 jacques F6BKI Le 27/01/2022 à 11:17, Simon Brown a écrit : Hi, -- - + - + - Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.
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Jacques RAMBAUD
taken transmiting a Tune
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jacques F6BKI
Le 27/01/2022 à 11:40, Simon Brown a écrit :
OK,
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Siegfried Jackstien
bonjour jacques
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at first ... do not use tune tone at that high level (leila is already crying outcause you are way over beacon level!!) second ... your pluto setup is NOT tuned correct (you should not have an xit setting of -10kc) and third ... your lnb setting should be (after tuning xo correction) set that you get the beacon closer to 750 ;-) dg9bfc sigi ps if you do not know how to set up ... just ask .. i will help you Am 27.01.2022 um 13:08 schrieb Jacques RAMBAUD:
taken transmiting a Tune
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Simon Brown
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-----Original Message-----
From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Siegfried Jackstien Sent: 27 January 2022 21:56 To: main@SDR-Radio.groups.io Subject: Re: [SDR-Radio] Pluto:: Spurious Emissions bonjour jacques at first ... do not use tune tone at that high level (leila is already crying outcause you are way over beacon level!!) second ... your pluto setup is NOT tuned correct (you should not have an xit setting of -10kc) and third ... your lnb setting should be (after tuning xo correction) set that you get the beacon closer to 750 ;-) dg9bfc sigi ps if you do not know how to set up ... just ask .. i will help you Am 27.01.2022 um 13:08 schrieb Jacques RAMBAUD: taken transmiting a Tune -- - + - + - Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.
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Siegfried Jackstien
hello jacques
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i measured the spurious emissions on 13 cm from the pluto ... sdrc is not causing that ... it is an slight iq imbalance (so where it is depends on where you transmit) ... these spurii are lower when you use lower power but they are still there thats why i recommend to add a bit more gain behind the pluto and use lower drive settings in it to be in fcc rules you should keep the power VERY LOW if you keep the pwr of the pluto at (example) -20 dbm you have -58 to -60 dbc (level of spurii compared to tune signal) and if then (depending on dish size and amp) your signal is at 40 db over noise the spurii are still 20 db below transpondernoise (and 40 db is already OVER beacon level!!) so ... what you see and measure is quite normal on the pluto sidenote a good warmed up pluto and a stable clock results in cleaner signals cause the iq calculation on boot shows better results the chips spread a bit as the results differ a bit from boot up to boot up (no idea why .. maybe rounding errors on the iq calibration?!?) but if you keep the drive lower the spurii fall below transpondernoise and will not hurt anybody greetz sigi dg9bfc Am 27.01.2022 um 13:08 schrieb Jacques RAMBAUD:
taken transmiting a Tune
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Siegfried Jackstien
NEVER NEVER NEVER USE OFFSET ON THE BIRD!!! not with lime and not with the pluto
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otherwise a spurii may cause trouble on another ones frequency!! offset is ONLY used in local terrestrical contacts (that the carriers rest does not block your rx signal) but then you maybe would not use fullduplex but halfduplex fullduplex may work with local contacts on a repeater but then also no offset is needed (repeater gives the offset so rx and tx are already not on same qrg) Simon .. in my view you could/should complete delete the offset setting in radio setup and set it fixed to 0kc if you have not found a good iq calibration (lime is a good example) then that carrier rest is at your 0hz spot and does not hurt other qsos (and you see it in if view and press tx calibration till it is gone) ... if you use an offset of say plus or minus 50 or 100 kc (or whatever) you may send out that carrier rest on another spot and do not see it (in first view) you even may transmit outside the band (and thats for sure not ok!!) so repeat ... NEVER NEVER EVER use offset tuning!!!! greetz sigi dg9bfc Am 27.01.2022 um 23:02 schrieb Simon Brown:
Don't forget optional offset tuning.
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