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2571Re: M Audio Delta 44 Output Signal Level Problem

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  • sv1eia
    Sep 5 11:33 PM
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      Hi Bob,

      As usual, spot-on !!

      > You could probably increase the gain a little in the QSE op-amp stage if needed for a SoftRock v6.3.

      That is the best and easiest to implement option (which I forgot to mention here although I'm doing it in almost all my rigs :-) ) changing just two resistors on the Tx opamp and Jim can have more than he can wish for.

      73,
      Christos SV1EIA


      --- In powersdr-iq@yahoogroups.com, "g8voip" <g8voi.reeves59@...> wrote:
      >
      > Hi Jim,
      >
      > Interesting, just to let you know I have no problem getting 5W out of my v4.3 mobo set up on the lower HF bands using a Delta 44 and the standard default soundcard set up. For 21MHz and above the power does drop off a little to 3 - 4W.
      >
      > Only differences I can think of is I am using one of George's v6.3ng boards as the driver, perhaps it has higher gain in the QSE part, or power output does also depend a little on the filter set you are using on the mobo. The set using the SMD inductors is a little more lossy so reduces the power output. Currently using the set with the hand wound toroids here.
      >
      > You could probably increase the gain a little in the QSE op-amp stage if needed for a SoftRock v6.3.
      >
      > 73, Bob G8VOI
      >
      >
      >
      > --- In powersdr-iq@yahoogroups.com, "wa4ywm" <wa4ywm@> wrote:
      > >
      > > Christos,
      > > Tnx for the reply. I just wanted to understand if I had any options.
      > >
      > > I have always used PSDR-IQ for SSB. I was using Rocky for PSK but with a VAC I'm now using PDSR-IQ for everything. I'll just need to always remember to set the level. By two replies I have received I see that I am not the only one with this issue.
      > >
      > > Thanks for your work and support on PSDR-IQ. It's a great piece of software.
      > >
      > > 73, Jim WA4YWM
      > >
      > > --- In powersdr-iq@yahoogroups.com, "sv1eia" <sv1eia@> wrote:
      > > >
      > > > Jim,
      > > >
      > > > That cleared quite a few things.
      > > >
      > > > Setting this at -10dBu is the default behaviour of PowerSDR as it is also indicated on the setup guide
      > > >
      > > > "CAUTION: It is extremely important to use the settings in the Delta Control Panel as described below in order
      > > > not to damage the SDR-1000 hardware due to overdriving the audio. Make sure the output is set to -10dBv
      > > > as shown in the screenshots below. The software will attempt to ensure this setting is in the right position on
      > > > startup."
      > > >
      > > > That means you have a few options
      > > >
      > > > 1. Return to your previous software.
      > > > 2. Wait until a next version comes and this will be added as a bypass for the homebrew rigs.
      > > > 3. Increase the PA bias setting on your mobo to achieve the same output.
      > > > 4. build something easy like that
      > > > -> http://groups.yahoo.com/group/powersdr-iq/files/USB2SDR%20OutputVoltageAmplifier/
      > > >
      > > > As a note, the +4dBu is a real high voltage of 3.5 (PP) volts on line out and it could be damaging, thats why they reduce it.
      > > >
      > > > Nominal values for homebrew rigs are between 1V to max 2V.
      > > >
      > > > 73,
      > > > Christos SV1EIA
      > > >
      > > >
      > > > --- In powersdr-iq@yahoogroups.com, "Jim Elmore" <wa4ywm@> wrote:
      > > > >
      > > > > Christos,
      > > > > OK. I will try to provide more detail.
      > > > >
      > > > > I want to permanently set the output of the Delta 44 to +4dBu. I cannot do this if I run PSDR-IQ.
      > > > >
      > > > > Here is what happens:
      > > > > 1. I open the Delta 44 Control Panel and select +4dBu by clicking the radio button for that selection. Then I click Done.
      > > > > 2. Start PSDR-IQ
      > > > > 3. At some point during the PSDR-IQ startup the output of the Delta 44 is set back to -10dBV (I do not want this behavior).
      > > > >
      > > > > I know that PSDR-IQ is doing this because I can see that the output has been set back to -10dBV when I open the Delta 44 Control Panel. I have also opened the Control Panel, started PSDR-IQ and watched while the output changes from +4dBu to -10dBV during the PSDR-IQ startup.
      > > > >
      > > > > I need this level from the Delta 44 because I am unable to obtain sufficient drive at the -10 dBV level to get 5W output from the MOBO.
      > > > >
      > > > > I hope this additional description is helpful.
      > > > >
      > > > > 73, Jim WA4YWM
      > > > >
      > > > > --- In powersdr-iq@yahoogroups.com, "sv1eia" <sv1eia@> wrote:
      > > > > >
      > > > > > Try to be a bit more descriptive, give us a few more details.
      > > > > >
      > > > > > Is it that you cannot have enough output whatever you do in PSDRIQ or is it only at application startup and then its ok?
      > > > > > Did you try to use the "Drive" slider?
      > > > > >
      > > > > >
      > > > > >
      > > > > > --- In powersdr-iq@yahoogroups.com, "Jim Elmore" <wa4ywm@> wrote:
      > > > > > >
      > > > > > > Hi Christos,
      > > > > > > I don't believe you are fully understanding my problem.
      > > > > > >
      > > > > > > Note that I have been using the Delta 44 card with Softrock for several years and more recently with the MOBO. It is the selected card.
      > > > > > >
      > > > > > > The issue is that PSDR-IQ sets the Output to -10dBV when it starts up. I would like to be able to leave the setting at +4dBu without having to worry about making that selection every time I use the SDR.
      > > > > > >
      > > > > > > I hope this clarifies the issue.
      > > > > > >
      > > > > > > 73, Jim WA4YWM
      > > > > > >
      > > > > > > --- In powersdr-iq@yahoogroups.com, "sv1eia" <sv1eia@> wrote:
      > > > > > > >
      > > > > > > > Jim,
      > > > > > > >
      > > > > > > > Are you using it as the selected supported option in setup,
      > > > > > > > or selected as 'Unsupported' ?
      > > > > > > >
      > > > > > > > In the links section you have to read the link named
      > > > > > > > "M-Audio Delta44 setup"
      > > > > > > > -> http://groups.yahoo.com/group/powersdr-iq/links
      > > > > > > > for proper supported setup of the card.
      > > > > > > >
      > > > > > > > Some tweeking is required on the newer driver versions of D44, you can search past posts here in the group and you will find what is needed.
      > > > > > > >
      > > > > > > > 73,
      > > > > > > > Christos SV1EIA
      > > > > > > >
      > > > > > > >
      > > > > > > > --- In powersdr-iq@yahoogroups.com, "Jim Elmore" <wa4ywm@> wrote:
      > > > > > > > >
      > > > > > > > > I use an output level from the sound card of +4dBu for my interface to the MOBO. This is needed to obtain a 5W output.
      > > > > > > > >
      > > > > > > > > What I have noticed is that PSDR-IQ causes the sound card output to default to -10 dBV when it starts up.
      > > > > > > > >
      > > > > > > > > How do I prevent this from happening? I would like to leave the output at +4dBu.
      > > > > > > > >
      > > > > > > > > Thanks & 73,
      > > > > > > > > Jim WA4YWM
      > > > > > > > >
      > > > > > > >
      > > > > > >
      > > > > >
      > > > >
      > > >
      > >
      >
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