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SG-230 troubleshooting

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  • Markus
    Hi all, Failure mode: - tunes perfectly at low pwr (5-10W) on 80m - activate (home-made) SmartLock, then increase pwr - at 20W and above, the SWR increases to
    Message 1 of 9 , May 3, 2008
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      Hi all,

      Failure mode:
      - tunes perfectly at low pwr (5-10W) on 80m
      - activate (home-made) SmartLock, then increase pwr
      - at 20W and above, the SWR increases to 2-3 and remains there
      - all other bands are ok at 100W.

      Checked all relay drivers as described in the troubleshooting document.

      With the SG-230 cover open, I noted all activated relays per band
      after tuning. I found that L5 and L6 (relays K11 and K12) are both
      active (not bypassed) on 80m _only_ . Will concentrate around these,
      but not really sure what to look for. Bad contact? Short circuit
      between inductor turns?

      Any ideas?

      vy 73, Markus
    • Andrew Cartwright
      ... Hi Markus, If it s working ok on all other bands then I would try adding a few feet to your antenna(If it s a wire one that is). It sounds as if your
      Message 2 of 9 , May 4, 2008
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        Markus wrote:
        > Hi all,
        >
        > Failure mode:
        > - tunes perfectly at low pwr (5-10W) on 80m
        > - activate (home-made) SmartLock, then increase pwr
        > - at 20W and above, the SWR increases to 2-3 and remains there
        > - all other bands are ok at 100W.
        >
        > Checked all relay drivers as described in the troubleshooting document.
        >
        > With the SG-230 cover open, I noted all activated relays per band
        > after tuning. I found that L5 and L6 (relays K11 and K12) are both
        > active (not bypassed) on 80m _only_ . Will concentrate around these,
        > but not really sure what to look for. Bad contact? Short circuit
        > between inductor turns?
        >
        > Any ideas?
        >
        > vy 73, Markus
        >

        Hi Markus,

        If it's working ok on all other bands then I would try adding a few feet
        to your antenna(If it's a wire one that is). It sounds as if your
        SG-230 is fine but having problems matching just 80M would point towards
        the antenna and not the tuner.

        HTH

        Regards

        Andrew - G7MNS
      • Markus
        Hi Andrew, Thanks for your reply. Adding a few feet to my wire antenna is unfortunately not possible: It s a vertical, using the well-known German 10m
        Message 3 of 9 , May 4, 2008
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          Hi Andrew,

          Thanks for your reply. Adding a few feet to my wire antenna is
          unfortunately not possible: It's a vertical, using the well-known
          German 10m fiberglass telescopic rod as support. But I can try to
          shorten it a bit. According to the SG-230 manual, 8ft are the minimum
          length required for 3.5MHz.

          The impedance of my antenna at 3.5MHz is in fact pretty high: 50-j351
          ohms, i.e. SWR=7. I concluded this from the fact that not a single
          capacitor of the SG-230 is active on 80m. The only active components
          are a couple of series inductors adding up to around 16uH.

          Running 100W means around 500Veff across these inductors. And the same
          500V are also across the (open) relay contacts which are parallel to
          the inductors. The OMRON relays used in the SG-230 are simply not
          specified for this kind of voltage.

          Over the past 10 years I replaced at least a dozen burnt relays in my
          SG-230 and came to the conclusion that these relays are simply unable
          to safely handle 100W CW.

          I'm not giving up yet, although the MFJ-927 looks like a very good and
          economic alternative.

          73, Markus HB9BRJ
        • kav
          Yo! Assuming that your vertical is ground mounted, try adding some wire at the highest point you can reach up the mast. That may be arms length, step ladder
          Message 4 of 9 , May 5, 2008
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            Yo!

            Assuming that your vertical is ground mounted, try adding some wire at
            the highest point you can reach up the mast. That may be arms length,
            step ladder height or whatever.

            If your element wire is uninsulated it's easier. If not you will have
            to decided if you are prepared to break the insulation for a temporary
            joint. If not then inductive coupling will have to do but it wont be
            so efficient.

            Anywho, take a wire maybe 8ft long and make the joint to your
            radiating element by your prefered method. Stretch it out as best you
            can at 90 degrees to the vertical. Go back to the radio and set the
            tuner away.
            See if you notice any change.

            If you do then a length change may be all that you need.

            If it changes things but not by a big enough margin add more wires.

            If you can. try adding four extra wires, evenly spaced around the
            vertical element, basically a capacity hat (should that be collar?),
            again just as high as you can reach.

            You should see a marked difference there with all frequencies needing
            to retune.

            If it fixes the 80m problem, consider making the hat out of self
            supporting wire or rods and just leaving it on.

            If none of the above helps at least you had a day playing antenna farmer.

            Regards
          • Markus
            Have inserted a 3m (9ft) detour at the base of my radiator. Same picture as before: Tunes fine at low power, oscillating SWR when applying 30W or more. Since
            Message 5 of 9 , May 5, 2008
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              Have inserted a 3m (9ft) "detour" at the base of my radiator. Same
              picture as before: Tunes fine at low power, oscillating SWR when
              applying 30W or more.

              Since only 4 L sections are active on 80m, I am going to resolder all
              inductors and relays concerned. After more than 10 years of outdoor
              operation, some solder joints are really looking ugly.

              Stay tuned, I'll get back with my findings. But not before next weekend.

              Tnx agn to all who have offered ideas and suggestions.

              73, Markus
            • John Champa
              Markus, Suggest covering those new solder joints with 1-2 layers of liquid eletrical tape. They will stay new looking for years. Also, suggest using silver
              Message 6 of 9 , May 5, 2008
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                Markus,
                 
                Suggest covering those new solder joints with 1-2 layers of liquid eletrical tape.
                They will stay new looking for years.
                 
                Also, suggest using silver bearing solder instead of the regular mix...stronger and tougher.

                Just my $.02 worth...
                 
                73,
                John, K8OCL




                To: Smartuners@yahoogroups.com
                From: hb9brj@...
                Date: Mon, 5 May 2008 17:56:08 +0000
                Subject: [Smartuners] Re: SG-230 troubleshooting

                Have inserted a 3m (9ft) "detour" at the base of my radiator. Same
                picture as before: Tunes fine at low power, oscillating SWR when
                applying 30W or more.

                Since only 4 L sections are active on 80m, I am going to resolder all
                inductors and relays concerned. After more than 10 years of outdoor
                operation, some solder joints are really looking ugly.

                Stay tuned, I'll get back with my findings. But not before next weekend.

                Tnx agn to all who have offered ideas and suggestions.

                73, Markus


              • Eric and Mary Beauchamp
                ... From: kav To: Smartuners@yahoogroups.com Sent: Monday, May 05, 2008 9:00 AM Subject:
                Message 7 of 9 , May 5, 2008
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                  ----- Original Message -----
                  From: kav
                  Sent: Monday, May 05, 2008 9:00 AM
                  Subject: [Smartuners] Re: SG-230 troubleshooting

                  Yo!

                  Assuming that your vertical is ground mounted, try adding some wire at
                  the highest point you can reach up the mast. That may be arms length,
                  step ladder height or whatever.

                  If your element wire is uninsulated it's easier. If not you will have
                  to decided if you are prepared to break the insulation for a temporary
                  joint. If not then inductive coupling will have to do but it wont be
                  so efficient.

                  Anywho, take a wire maybe 8ft long and make the joint to your
                  radiating element by your prefered method. Stretch it out as best you
                  can at 90 degrees to the vertical. Go back to the radio and set the
                  tuner away.
                  See if you notice any change.

                  If you do then a length change may be all that you need.

                  If it changes things but not by a big enough margin add more wires.

                  If you can. try adding four extra wires, evenly spaced around the
                  vertical element, basically a capacity hat (should that be collar?),
                  again just as high as you can reach.

                  You should see a marked difference there with all frequencies needing
                  to retune.

                  If it fixes the 80m problem, consider making the hat out of self
                  supporting wire or rods and just leaving it on.

                  If none of the above helps at least you had a day playing antenna farmer.

                  Regards

                • Eric and Mary Beauchamp
                  Thanks for your reply kav. I am going to try and get someone out to the boat to do basic reality checks before I make it worse. Beau ... From:
                  Message 8 of 9 , May 5, 2008
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                    Thanks for your reply kav. I am going to try and get someone out to the boat to do basic reality checks before I make it worse. Beau
                    ----- Original Message -----
                    From: kav
                    Sent: Monday, May 05, 2008 9:00 AM
                    Subject: [Smartuners] Re: SG-230 troubleshooting

                    Yo!

                    Assuming that your vertical is ground mounted, try adding some wire at
                    the highest point you can reach up the mast. That may be arms length,
                    step ladder height or whatever.

                    If your element wire is uninsulated it's easier. If not you will have
                    to decided if you are prepared to break the insulation for a temporary
                    joint. If not then inductive coupling will have to do but it wont be
                    so efficient.

                    Anywho, take a wire maybe 8ft long and make the joint to your
                    radiating element by your prefered method. Stretch it out as best you
                    can at 90 degrees to the vertical. Go back to the radio and set the
                    tuner away.
                    See if you notice any change.

                    If you do then a length change may be all that you need.

                    If it changes things but not by a big enough margin add more wires.

                    If you can. try adding four extra wires, evenly spaced around the
                    vertical element, basically a capacity hat (should that be collar?),
                    again just as high as you can reach.

                    You should see a marked difference there with all frequencies needing
                    to retune.

                    If it fixes the 80m problem, consider making the hat out of self
                    supporting wire or rods and just leaving it on.

                    If none of the above helps at least you had a day playing antenna farmer.

                    Regards

                  • Markus
                    Invested a couple of hours yesterday and solved my SG-230 problem. My ground ( counterpoise ) wire was corroded or even interrupted. This led to an extremely
                    Message 9 of 9 , May 11, 2008
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                      Invested a couple of hours yesterday and solved my SG-230 problem.

                      My ground ("counterpoise") wire was corroded or even interrupted. This
                      led to an extremely high ANT impedance, especially on 80m. The SG-230
                      was still able to find a match, but only used a series L of 16uH, no
                      caps at all. At 100W the voltage across the L reached around 300V
                      (calculated), which was too much for the (open) relay connected in
                      parallel. I replaced 2 relays which visually seemed suspicious.

                      My experience after more than 10 years: The relays which bypass the
                      inductors are suffering most. I've replaced all of them by now
                      (writing the replacement date on their plastic covers).

                      Using the SG-230's active relay information plus AC6LA's XLZIZL
                      spreadsheet, I found that the antenna impedance has come down to a
                      safe range that the SG-230 can handle.

                      Now the tuner uses a real pi (C-L-C) configuration also on 80m, which
                      reduces the voltage across the inductor to 180V.

                      My conclusion: With outdoor installations, periodically inspect all
                      your connections and wires. It's not always the tuner that's the culprit!

                      73, Markus
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