Building a dummy load for less than $5
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Cool article in Nuts and Volts mag about building a dummy load for under $5:?
 Not quite as convenient as some of the commercial units but....it works! Speaking of which, I recently picked up the for $129; virtually identical to the old HeathKit "Cantennas". It works great for helping me tune up my new (to me) Ameritron AL-811H amplifier. Funny, when I first got my ticket, I wondered why anyone would need a dummy load when you can just put the load into an antenna. I certainly understand why now--especially when you're trying to tune things at QRO power levels and need a constant 50-ohm load.? I looked at some of the other "dry" dummy loads but their derating curves were disappointing. Like a minute or less at QRO load levels. Here's the derating curve for the oil-based dummy load...so at my amps maximum output (800 watts) I can run it for about 12 minutes. Much better! 73, Mark -- --------------------- Mark Ehr | K0EHR President, 285 Tech Connect Radio Club Littleton, Colorado k0ehr@... Check out my ham radio blog: |
Mark Ehr | K0EHR