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RE: [GenesisRadio] Power display issues??

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  • Tim
    That fixed the TX levels. Tnx for the link. On the RX side, when I set a band I.e. 40 meters S-9 level, the other bands are close, but not identical. Would
    Message 1 of 10 , Feb 24, 2013
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      That fixed the TX levels.  Tnx for the link.

      On the RX side, when I set a band I.e. 40 meters S-9 level, the other bands are close, but not identical.  Would component variations in the BP filters affect the signal levels (and the displayed signal level)?

      Tim W5FN

      From: Bruce   KF1Z
      Sent: ‎2/‎24/‎2013 6:48 PM
      To: GenesisRadio@yahoogroups.com
      Subject: Re: [GenesisRadio] Power display issues??

      Calibrating the S-meter for separate bands is not needed.
       
      You are actually calibrating the soundcard input for the S-meter.
      Separate bands are all treated the same , as they should be.
       
      There IS a way to adjust the minumum/maximum display level...
      Just change it in "display' tab for each band, and those settings are automatically saved.
       
       
       
       
      The document I was referring to is G11 TX adjustment by KF1Z
      on the main Genesis website page
       
      bruce
       
       
      From: Tim
      Sent: Sunday, February 24, 2013 7:40 PM
      Subject: RE: [GenesisRadio] Power display issues??
       
       

      Aah, that should fix it.

      Is there a similar function to calibrate the s-meter on a band per band basis?  I tried the calibrate function, but it seemed to change all bands.

      BTW, the only calibration docs I saw is the one that is mixed in with the assembly docs.

      Is there a separate document for calibration?

      Tnx again!!

      Tim W5FN

      Sent from my complicated hand-held thingie.

      From: Bruce   KF1Z
      Sent: ‎2/‎24/‎2013 5:58 PM
      To: GenesisRadio@yahoogroups.com
      Subject: Re: [GenesisRadio] Power display issues??

      You need to specify.....
       
       
      WHAT meter is reading the FED power?
      The service monitor? or the meter in GSDR?
       
       
      If the GSDR meter, ( and output power is steady at 10w on the service monitor/...)
       
      Then read the part of the calibration docs that tells you how to set the meter.
      That is the ADC Offset.
      In the same tab as Gain by Band settings
       
       
      Basically, the same as Gain by band, except the ADC offset only deals with the meter reading.
       
      Set these for each band to make your GSDR power meter read the same as external meter.
       
      I have not seen one yet that all the numbers would be the same.
      The ADC offset will vary by as much as 5 , but usually within 2 or 3.
       
       
      ( you are  correct about the label, BTW )
       
      Bruce
       
      From: Tim
      Sent: Sunday, February 24, 2013 6:30 PM
      Subject: [GenesisRadio] Power display issues??
       
       

       

       

       

      Hi All,


      I just finished the multi-band board, and am seeing some funny things on the power meter.

      All bands have been adjusted via the PA adjustments for 10w on my service monitor.

      Here is what I am seeing:

      BAND     FWD PWR     TP10 Voltage

      160        4.4 W       2.003
      80        4.4 W       1.989
      60        4.0 W       1.890
      40        9.2 W       1.939
      30       10.0 W       2.038
      20        9.9 W       1.929
      17       10.1 W       1.897
      15       10.8 W       1.911
      12        4.2 W       1.926
      10        4.0 W       1.902
        6       10.0 W       1.891


      Just curious how I can be seeing 4.4W on the display, when the TP10 voltage is 2.003.

      According to the calibration instructions, I set the output power for 10W on the power meter, then adjust P2S for 2.0 volts.
      on Page 10 of the schematics, the TP10 shows a label of TO_REW_UC.  ( I think this label should be TO_FORW_UC).

      Anyhow,. since it goes directly into the micro's A/D converter, how can the value be modified, if not in software?

      Thanks,

      Tim W5FN


    • Bruce KF1Z
      Yes! And the Low-pass filter too! But also keep in mind..... I don t know what you are using for a signal generator.. how well it is calibrated etc... But
      Message 2 of 10 , Feb 24, 2013
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        Yes!
         
        And the Low-pass filter too!
         
        But also keep in mind.....
        I don't know what you are using for a signal generator.. how well it is calibrated etc...
        But anything else in the RF path will affect the signal too of course...
         
        Coax length, tuner in-line, etc..
         
        But filters play a part certainly.
         
        In some cases, some slight changes in the inductors may be needed ( only if drastic differences, or you want to be "picky" Smile  )
         
        First, you can isolate the issue by by-passing the low-pass filter to rule it out.
         
        Use the 2nd RX antenna bnc and select "Second RX input", in Setup > General > Hardware Config.. in GSDR
         
        If the signal is the same strength as it was in the normal position, then the Band-pass filter is where changes may need to be made.
        If the signal has improved, then it's the low-pass filter.  etc.
         
        the filters could lower the input signal by as much as ( but should NOT be MORE than...)  1 or 2 db
         
        You can also bypass ALL the filters, by removing the filter board, and running a jumper between J1B and J2B, as in the assembly of G11 on page 7.
        Make note of a signal generator's signal ,  try on all bands...
        Then put filter board back, and run the test again, and compare the signal strength.
         
        If there is more than 2db reduction in the signal strength ( not NOISE, just the signal)  then some filter "tweaking" may be needed.
         
         
        The reasons for filter variations are:
         
        1) some wrong, or bad component
        2) toroid winding "style".   IE: winding spacing, turns overlap, etc.
        3) solder joints
        4) capacitor tolerance
         
         
        Bruce
        kf1z
         
         
        From: Tim
        Sent: Sunday, February 24, 2013 8:08 PM
        Subject: RE: [GenesisRadio] Power display issues??
         
         



        On the RX side, when I set a band I.e. 40 meters S-9 level, the other bands are close, but not identical.  Would component variations in the BP filters affect the signal levels (and the displayed signal level)?

        Tim W5FN
      • Tim
        Hi Bruce, Thanks for all the help! Power is spot on for all bands, and the receiver is now proper as well. I only had to tweak the BPF coils on the 6m to get
        Message 3 of 10 , Feb 25, 2013
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          Hi Bruce,

          Thanks for all the help!

          Power is spot on for all bands, and the receiver is now proper as well.
          I only had to tweak the BPF coils on the 6m to get all of the readings
          within 1dB.

          I forgot that my HP8924c falls off below 20mHz (original sig
          generator). I switched over to one of my other signal generators that
          work in the HF range, and all is good.

          Thanks!

          Tim W5FN
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