[Elecraft] Product Suggestion - 500W Dummy Load

[Bob McGraw - K4TAX]

Don, et al:

I do agree that we typically do not need a precision load nor do we 
likely need a "full legal limit CCS" load.   Most loads have a power vs. 
time de-rating curve.  Just following that practice will save on lots of 
$$ and space.

Yes the Cantenna loads are generally suitable.  I find the Z to be 50 
ohms +/- 10% or so.  They will handle legal limit power for 2 or3 
minutes and 100 to 300 watt power for almost CCS times.  As a rule, they 
are good for HF and become a bit less so suitable for VHF.

I prefer dry loads as they are less "messy" where one uses an oil filled 
load it seems they all want to weep a bit.  Oh my gosh should on kick 
one over and the lid separate.  As a suggestion, solder the lid in place 
at 3 or 4 locations around the edge.

It would do well for folks to consider switching and tuning methods so 
as not to put a signal on the air.  Although this typically can't be 
done with automatic type tuners,  with manual tuners, using an antenna 
bridge will allow one to adjust the tuner for a proper match and not put 
a signal on the air.    Then with older amps, tuning those into a dummy 
load again will not put a signal on the air. When the amp is switched to 
the tuner then all is well and no QRM has been generated.

73 Bob, K4TAX

K3S s/n 10,163


On 9/17/2015 8:37 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.
>
> While the "Tune Up" situation has been largely eliminated for "No 
> Tune" amplifiers, there is still the question of how to do a TUNE into 
> an antenna when you have a tuner such as the KAT500 in line - but that 
> tunes into the antenna at reduced power with the Elecraft K-line, and 
> the tune cycle is relatively short.
>
> The net that I see of all that is one does not need a precision dummy 
> load for high power levels.
> At the 100 watt level, I do find a need for precision dummy loads 
> which can be used for lab measurement devices, bu at higher power 
> levels in the normal hamshack, I do not understand a need for a 
> precise 50 ohm non-inductive load (as long as you do not stray too far 
> from that 50 ohm point.
>
> In other words, the gallon size "cantenna" dummy loads should suffice 
> for most purposes in the ham shack that I can conceive of - primarily 
> providing a suitable load for a high power transmitter for routine 
> test purposes.
>
> Those who do precision measurements at high power levels will have to 
> invest in precision dummy loads, but for typical ham use, I don't 
> think that level of precision is necessary.  Such precision comes at a 
> cost.
>
> 73,
> Don W3FPR
>
> On 9/17/2015 8:19 PM, Byron Peebles wrote:
>> I'd love to find Elecraft offering a 500W dummy load to match the 
>> K-Line.
>> No one even makes a sturdy paint can anymore.
>>
>> 73, Byron
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