[Elecraft] Product Suggestion - 500W Dummy Load

[Jim Brown]

On Thu,9/17/2015 6:37 PM, Don Wilhelm wrote:
> While a dummy load that has a power rating greater than your maximum 
> transmit power is a worthwhile addition to any hamshack - at higher 
> power levels, I do not see them being used as precision measurement 
> devices, but only as a temporary load for the purposes of "tuning up" 
> or operating into a dummy load for test purposes. 

Remember also that dummy load ratings include a duty cycle. The cheap 
stuff has a very short duty cycle -- one might be rated 100W for 1 
minute. :) It's all about heat -- do you get hot enough to damage it?

Duty cycle can be interpreted two ways. One is to use a series of dits 
to tune up, which gets you to full power but half the time. That's what 
I do. I just sold a nice little keyer-pulser that W2VJN used to make. 
Its duty cycle could be adjusted as low as 20%.

Another way to interpret it is how LONG you transmit into it. My big 
professional oil filled dummy load is rated 500W for a long time (don't 
remember the spec). I transmit dits (and even RTTY) into it at legal 
limit for a minute or so, and it doesn't overheat. And then I let it 
cool off.

73, Jim K9YC