Discussion in 'Amateur Radio Amplifiers' started by W5DP, Oct 22, 2018.

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  1. W5DP

    W5DP XML Subscriber QRZ Page

    I need to rewire my SB220 for 110vac. I saw in the manual one place where you move two jumper wires, but I suspect that that's not the only change. The manual doesn't seem to be very helpful, at least for me.

    Anyone that can help would be much appreciated!

  2. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    That actually is the only change.

    Unless you have a dedicated 20A AC outlet with nothing else loading it, you can't run an SB-220 at "full power" from 120V, but you probably know that.
    WA7PRC likes this.
  3. W5DP

    W5DP XML Subscriber QRZ Page

    I have since found out that my sb220 has mod kits installed, one which is the soft start, that needs to be swapped out for the 110v version, which I now have on order.
  4. KD2ACO

    KD2ACO Platinum Subscriber Platinum Subscriber Life Member QRZ Page

    What radio are you going to drive it with? You may want to make sure one of the mods is a soft key unless the radio can handle high voltage (has relay contacts instead of a transistor to drive the key line)... but you probably know that. :p
  5. W5DP

    W5DP XML Subscriber QRZ Page

    I'm running an Icom 756 Pro III, and I have an outboard TR Relay to handle the switching. The amp ran flawlessly at my old QTH where I had a 220vac circuit, so I just need to get this mod done and amp converted to 110vac, so I can put it back in line at my new QTH. Hi! Hi!
  6. W5DP

    W5DP XML Subscriber QRZ Page

    I'm also thinking about selling my sb220 since it's limited not running on 110vac, and purchase a smaller amp that is more appropriate for my 110vac hookup.
  7. WR2E

    WR2E Ham Member QRZ Page

    No way to get a 240VAC line pulled in?
  8. W5DP

    W5DP XML Subscriber QRZ Page

    Impractical, which would make it expensive.
  9. KD2ACO

    KD2ACO Platinum Subscriber Platinum Subscriber Life Member QRZ Page

    You could change a couple of wires inside and run that amp at 6 or 700 watts. You just have to keep the drive power in check... not optimum, but not that hard to do. You would still want a circuit that the amp has pretty much to itself.
    An AL-80B runs OK at 120v.
    An SB-200 runs OK at 120v.

    Everyone will argue that they run better at 240v, which is true, of course.

    I've run an SB-200 and an AL-80B at 120v because that's the only regulated power in my shack/shop#1, and they work fine for me like that. I don't need to squeeze everything out of them... 500-700 watts is plenty of power here for my casual operation.
  10. WD5ABC

    WD5ABC Ham Member QRZ Page

    I had the same problem here, I don't have a good way to get 220v where my shack is so I'm running my freshly-restored Drake L-4B on 120v. It's fine at 700-800watts, and at that power it should last forever. I was hesitant to do it but it does fine and I only drive it with about 40-50w.
    KD2ACO likes this.

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