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World's Ugliest Dummy Load

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by KG4GVL, Feb 12, 2013.

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Is this Really the World's Ugliest Dummy Load?

Poll closed Feb 19, 2013.
  1. YES

    8 vote(s)
    50.0%
  2. NO

    5 vote(s)
    31.3%
  3. The OP is the only Dummy I see here.

    3 vote(s)
    18.8%
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  1. KG4GVL

    KG4GVL Ham Member QRZ Page

  2. KG4GVL

    KG4GVL Ham Member QRZ Page

  3. KC9UDX

    KC9UDX Platinum Subscriber Platinum Subscriber Life Member QRZ Page

    EDIT: Nevermint... you fixt it already..Sorry, the page you were looking for in this blog does not exist.
     
  4. KC9VFO

    KC9VFO XML Subscriber QRZ Page

    I like that you have a sense of humor! ;)
     
  5. KG4GVL

    KG4GVL Ham Member QRZ Page

    Thanks for watching out!
     
  6. KG4GVL

    KG4GVL Ham Member QRZ Page

    Thanks for the votes guys!
     
  7. K8JD

    K8JD Ham Member QRZ Page

    No, mine is a big pale green thing, about a foot long, with thick heat radiating fins all along the top side.
     
  8. KG4GVL

    KG4GVL Ham Member QRZ Page

    I would like to see pics!
     
  9. WA7PRC

    WA7PRC Ham Member QRZ Page

    For high power, I now use a homebrew air-cooled dummy load, made with four 50Ω/400W flange-mount resistors in series-parallel:

    [​IMG][​IMG]
    [​IMG][​IMG]

    Tests indicate it can handle 1600W all day with the temperature staying on the good side of the curve. VSWR < 1.5:1 to at least 54 MHz (I didn't bother sweeping it higher). I built it using scrapped parts from my former employer. Similar RF power resistors can be found on ebay and from surplus suppliers. It should be noted that the common TO-package non inductive power resistors are rated full power at 25°C (77°F) and derate above that temperature. The resistors I used (Anaren #RFP-400-50R) don't derate until you get them to 100°C (212°F).

    Yeah, it's not as nice as a Bird, etc. But, it works fine for my purposes, and didn't cost nearly as much as a Bird, etc. In fact, all the parts were scrapped by a former employer (cost = zero). I still have a couple dozen resistors and two heatsinks. I use my refurbished Heathkit Cantenna for lower power tests.

    Henry Radio sells new surplus flange-mount terminators* on ebay. They currently have two 100Ω/800W terminators for $100 (link) that ought to work well at much higher frequencies. Hmm! :)

    * A terminator has one terminal connected to its mounting flange. A resistor has neither terminal connected to its mounting flange. Terminators can be used only singly or in parallel. Resistors can be used singly, in parallel, series, or series-parallel.
     
  10. NY7N

    NY7N Ham Member QRZ Page

    I dunno, mine might give it a run for its money...

    dummyload1.jpg

    :p

    Works okay for the rig barefoot (you know, when submerged in mineral oil inside the paint can, not pictured here because everyone knows what a quart paint can looks like), not quite so helpful when I have the SB-201 fired up.
     
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