Discussion in 'General Technical Questions and Answers' started by K4LRH, May 11, 2018.

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  1. K4LRH

    K4LRH Ham Member QRZ Page


    What is the toroid looking device in this POWER SIFTOR and what is its function in this circuit ?


    Jack; K4LRH

    Attached Files:

  2. KA9JLM

    KA9JLM Ham Member QRZ Page

    Line Filter
  3. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    I don't think so. A Power Siftor normally provides line isolation as well as filtering and transient protection, but the "isolation" is very key: They have near-zero (microamp level) line to ground leakage and normally this requires complete transformer isolation between line and load.

    As such, looking at the photo, I'd think that's a transformer.
    KB4QAA likes this.
  4. KA9JLM

    KA9JLM Ham Member QRZ Page

    I agree.

    A line filter.
  5. KD2ACO

    KD2ACO Platinum Subscriber Life Member Platinum Subscriber QRZ Page

    After looking around, it appears they made these line isolators in pretty small VA sizes, like 200, 300, 400VA, etc.

    That's a pretty dinky transformer. It may be 300VA. The square can looks like a line filter. What's the writing on the front say? Any model number?
    Last edited: May 11, 2018
  6. K4LRH

    K4LRH Ham Member QRZ Page

    I tried the Google thing. Apparently, they no longer are in business. The Model is a: PS30DD; Transient suppression voltage: 150; Amps: 30; Operating voltage: 120 VAC. I've included a 'hard to read' picture of the label.

    Attached Files:

  7. KD2ACO

    KD2ACO Platinum Subscriber Life Member Platinum Subscriber QRZ Page

    I'd have to revise my guess then that the circular thing is a toroidal line filter, and who knows what's in the box as a transient suppressor.
    Just guessing at this point. I haven't found anything on line about this specific box either.
    Last edited: May 12, 2018
  8. AF7ON

    AF7ON Ham Member QRZ Page

    In my days of lightning/surge protection, I came across just about every power protection device there is! In my recollection, Power Siftor is a trademark of Current Technology, one of the biggest Texas-based companies in the field. Amtek may well have been a private label.

    I don't recall their devices ever having used isolation transformers and I was always suspicious of "magic" components hidden in epoxy potting! As I recall, it is a surge suppressor with line filtering - but we are talking 1970s technology here! They had a decent reputation for reliability, as I remember.

  9. KA9JLM

    KA9JLM Ham Member QRZ Page

    The extra wire gives it away as being a filter.

    How it is wired will tell what it is.

  10. K4LRH

    K4LRH Ham Member QRZ Page

    I disconnected all wires to & from this component plus removed it from the enclosure. There is no continuity between any of the leads. And the device is too light to contain magnetics.

    Jack; K4LRH

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