Sunday, April 10, 2022

Audio Dummy Loads Finished

 Between the botched flooring, and the delays, and then the plumbing leaks and plumbing repair, I've been a tad busy. It's also the start of the Spring Lawn Care Season, so there's been a lot of that going on. Hoses to lay, newly seeded areas to be kept moist, and trees and shrubs to feed.

And The Little guy was over Thursday night and all day Friday, then The Kids came by for dinner with the New Little Guy, who's taken quite a shine to me and my funny noises and faces.


ANYWAY..... I had most of the parts and a sketch, so I sat myself down and built these up.

The resistors are 8 Ohm, 100 Watt, Non-Inductive resistors in a series/parallel connection. It gives me 8 Ohms at 400 Watts, bigger than any amplifier I'll most likely encounter. I also tapped the point between the two 4 Ohm sections, which also gives me 4 Ohms at 200 Watts, also more than any amp I'm likely to encounter.

So now that I have these, and all my Test Equipment appears to be squared away, I can finally get back on the big Pioneer SX-980 receiver that's been a doorstop the last few months.

Rock On!


 




10 comments:

  1. Very cool . . . that is until you heat the load up with a couple hundred watts of screaming SX-1980 audio. Nice project.

    ReplyDelete
    Replies
    1. GACK!!! This is a 980, NOT a 1980. Just caught my mistake. Maybe I was dreaming of something?

      This one puts out 100WPC.

      Delete
  2. Always looking for a bright spot, maybe all this Wyoming wind we have been having will give you more insight on your antenna projects.

    ReplyDelete
    Replies
    1. Ten inch long 4x4 posts? What a typo will do to make one laugh!!

      Delete
    2. Well, everything I've put up in the last 4-1/2 years has stayed up, so I'm probably OK.

      Now that my son is here and I have the post-hole auger running again, we're going to plant the two 10 FOOT long 4x4 posts I have. One will get the 14 MHz vertical that's currently on a 5' tripod with 50 lbs of sand at the bottom, and the other one will get the 50MHz vertical I bought a couple of weeks back.

      Delete
    3. Yeah, I don't type very well these days!

      Corrected it for you...

      Delete
  3. Yeah, but at a snail's pace!

    ReplyDelete
  4. At least you haven't had to build a 50 ohm 40 KW dummy load so far. One radio station I worked for had a 5KW homemade dummy load that used a bunch of huge incandescent light bulbs. Probably a good thing the transmitter was a late 50s vintage tube type Gates AM transmitter. I don't think one of the solid state transmitters like the Nautel 10 KW I installed at another station would have liked the load.

    ReplyDelete
    Replies
    1. I've built some pretty big loads, but for the really big stuff, I always used commercial equipment. We had a Bird 3~30MHz 25kW continuously rated load onboard the Iowa, and the biggest I've used was a 250kW water-cooled calorimeter for testing 100kW amplifiers at Fermilab.

      Delete

Keep it civil, please....

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