Re: #pluto #pluto

Siegfried Jackstien

aehem ... how can it be that you do not receive your own transmission?? but have TWO frequencies where you really send??

something is puzzled there but i can not figure out what

about stability of usb connection ... yes ... do the ground mod (easiest is a short bridge from L7 to D3)

what gain and drive do you have set in menue??

and you say that you can change tx frequency (say with the mouse in numbers box) and the tx frequency plus its spurii stays fixed??


you use the pluto with external reference i guess??

did you check that the 40 megs HAVE TO BE SWITCHED ON when you start pluto?? maybe the frequency was not there ... tx calibration did not work ... and that may explain why there is a ghost signal ... and why tx qrg change does not work

but that is all just shooting in the dark ... NEVER have seen such a thing here

grreetz and good luck to find the fault

dg9bfc sigi

ps 3.0.18 is just before release (i guess) ...

Am 18.12.2019 um 13:35 schrieb Frank Schneider:

Hallo Sigi,

Vielen Dank fuer die Antwort,


Please explain for dummis: why must I engage the geo beacon? I don’t need it for frequency stability.

I use the Pluto for a few month now. Works fine with v3.0.15  No spurious. I put the curser over the signal I want to respond to and push the PTT. Works.

Only problem is the disconnects of the USB, in spite of the mods suggested to the grounding  in the Pluto. Aber das ist eine andere Geschichte.

Offset is off

Re the gain: That is what I mean with gain sensitivity being high.

With 3.0.15, Audio gain 60, compression 60, I need a drive setting of 75 to create a two tone signal 6dB below the beacon. No spurious.

With 3.0.17 the drive setting is 18,  the spurious are there and the tx output frequency is fixed, no matter what the tx frequency window says.

Am well aware about overdriving things. Maybe there is some default setting I have not discovered yet?





From: <> On Behalf Of Siegfried Jackstien via Groups.Io
Sent: Wednesday, December 18, 2019 13:08
Subject: Re: [SDR-Radio] #pluto


you did not engage geo beacon (or why are you txing out of your own rx window?!?)

i use a pluto now for nearly a year (as long as qo100 is on air) ... and my pluto is ALWAYS txing fine (no spurii to be seen)

do you have tx offset switched on?!? (switch it off ... no need on qo100 for tx offset!!)

i see that you use a very low drive from the pluto (only 20%)... means you have a very high gain amp BEHIND the pluto towards antenna

that means that "ghost signals" or spurii that would normally not be seen ... are then still to be seen on the transponder

add attenuator behind pluto and use a bit higher drive with such a high gain amplifier (guessing you use a datv setup on nb transponder?!?)

best is drive area of 80 to 90 % (that gives cleanest signal here on my station) settings above 90 ... and the pluto is not so clean anymore ... (same as with all trx ... fullpower gives dirty signal)

with such a high gain behind the pluto you will see those ghost signals ... adding attenuator and using higher drive in pluto may solve that

greetz sigi dg9bfc


Am 18.12.2019 um 09:02 schrieb frank@...:

The spurious signals are only there with the latest console. Thes frequencies are fixed. They don't change. Never mind what the display says.

Join to automatically receive all group messages.