New fuse for Astron 35?

Discussion in 'General Technical Questions and Answers' started by KM6LYW, Dec 21, 2018.

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  1. WR2E

    WR2E Ham Member QRZ Page

    Superconducting fuses!

    Bet we could sell them to the audiophools on ebay!

    Of course there MUST be an R in any fuse element!
  2. W9WQA

    W9WQA Ham Member QRZ Page

    no overload foldback. those fuses have higher resistance hence the drop in the fuse
  3. WR2E

    WR2E Ham Member QRZ Page

    Let me understand this better...

    You have a 12 V supply and a 5A fuse that you measured .7 Ohms.

    Right so far?

    You put that fuse across the supply and it only glowed and did not blow?

    The supply didn't fold back? You actually measured the voltage during the fuse short circuit? What was the actual voltage across the fuse?

    So you're saying that a 5A fuse with 17A through it didn't blow, it only glowed?

    Something doesn't smell right.
    Last edited: Jun 13, 2019
  4. W5LZ

    W5LZ Ham Member QRZ Page

    ... smell? Hey, that's just the fuse...
    WR2E likes this.
  5. WA9SVD

    WA9SVD Ham Member QRZ Page

    If the supply didnt 'foldback," I'd be ducking the glass shrapnel...:eek::rolleyes:
    WR2E likes this.
  6. W9WQA

    W9WQA Ham Member QRZ Page

    ill try to redo that test. note those fuses are resistive wire and yes they do glow. probably the 1.4 was used. its been a while.
    AND i was lost here this week,lost password when comp crashed. had to restore back 12yrs as it was new..a real mess. i tried a hundred ways to navigate the forum process,frustrating.

    ill try to set everything as it was with the 2 meter rig and the "dimming" out. it did happen as described...later
    Last edited: Jun 15, 2019
  7. NL7W

    NL7W Premium Subscriber QRZ Page

  8. W9WQA

    W9WQA Ham Member QRZ Page

    more questions on astron 35. mine is solid regulation at 18 amps with no drop at the output terminals,fine. but disconnected from rig i hear it "hummm',no load.

    next,with the rig on idle receive,about 1 amp,in about 3 hours the transformer is HOT to touch.?

    it measures 76 at cold start and 114 deg hot, with an ir gun.
    sound ok?
  9. N8VIL

    N8VIL Ham Member QRZ Page

    Many hardware stores have a selection of 250 volt fuses in various current ratings. At least by me they do and I purchased many there.
  10. W5LZ

    W5LZ Ham Member QRZ Page

    If a fuse 'glows' visibly then it's going to pop with -any- additional current through it, period. If it ever get's to that point, I have to think you are pushing something entirely too hard! It's a miracle it hasn't blown. So, the choices are, reduce the current draw, or get a bigger fuse. That bigger fuse just means there's gonna be a 'pop' somewhere else.

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