New fuse for Astron 35?

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

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  1. K7TRF

    K7TRF Premium Subscriber QRZ Page

    Because the resistance, R, isn't adjustable by the user. The resistance is implicit in the design and from a functional standpoint of protecting wiring, current is more relevant to designers that will incorporate the fuse in their designs.

    Realistically even power is simplified as fuses are rated in terms of energy or power integrated over time as in: I^2R*t in the simplified case.
    K8MHZ likes this.
  2. K8MHZ

    K8MHZ Ham Member QRZ Page

    How about we go with the fact that the amperage rating on the fuse is the rating of the load, and what goes on inside the fuse to get to that point really doesn't matter when trying to explain why they are rated in amps.

    Circuit breakers are also rated in amps, not watts, and they can operate magnetically and pretty much ignore I^2R effects.
  3. KM6LYW

    KM6LYW Ham Member QRZ Page

    In the end, the fuses on Amazon were China copies, slightly less than the posted standard dimensions (metric "equivalents" were accurate however), and ultimately fit too loose in the fuse holder. They took a picture of an actual Bussman fuse however.

    I emailed Astron and they said they use "Bussman AGC-8" fuses, which, as far as I can tell are out of production, but I was able to find new-old-stock on ebay for $2/ea. It looks like Bussman makes a new 7.5A version, but with my luck, that'd blow.

    Anyhow, hopefully this helps the next guy find a fuse for their Astron35.

    thanks for all the help guys.

  4. KF5LJW

    KF5LJW Ham Member QRZ Page

    Try unplugging the PS before working on it and the fuse will not blow. FWIW unplug anything electrical before working on it. :confused:
    KK4CUL likes this.
  5. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    AGC-8 fuses aren't discontinued, I can get them "new" (current manufacturing) all over the place. AGC isn't owned by Bussman or anyone else; as I recall it just stands for "all glass cartridge" fuse.

    Even my local Fry's Electronics big-box retail store has them in stock, and that's where I'd normally get them.
    KM6LYW likes this.
  6. KD8DEY

    KD8DEY Ham Member QRZ Page

  7. KA9JLM

    KA9JLM Ham Member QRZ Page

    Are you sure ?

    It has a lot of resistance after it blows.
  8. WR2E

    WR2E Ham Member QRZ Page

    Suggest one does NOT click on that link for from Dinesh Battula (DINGBAT5) for more info.

    I don't believe the website is what it's purported to be.
  9. WR2E

    WR2E Ham Member QRZ Page

    Thank you mods for removing the referenced post.
  10. W9WQA

    W9WQA Ham Member QRZ Page

    line voltage fuses in 12v circuits glow red as volts drop on overload! a short wont blow some of them but the foldback helps!!

    i had one in a power block testing a 2 meter rig. it would key up and them go dim!i measured volts at the fuse,and then saw it glow!!
    Last edited: Jun 11, 2019

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