[Elecraft] KX3 Heatsink discussion

[Howard Hoyt]

Sorry of this appears twice, I got a bounce on the first submission:

The Pro Audio Engineering Kx32 Heatsink has more surface area than any 
other commercially available KX3 heatsink.  Regarding mass, more is not 
necessarily better.  If you take two heatsinks with the same surface 
area, on the initial key-down the one with more mass gives a longer 
initial warmup time.  Unfortunately it also retains heat longer, meaning 
on the subsequent transmit cycles, it still retains heat from the 
previous cycle.  We strove to minimize the mass of our heatsinks, the 
limitation ended up being rigidity and resistance of the fins to damage.

The limitation on convective heatsink efficiency is not the thermal 
conductivity of aluminum, it is surface area.  Our tests show very 
little thermal Δ (delta if your browser is ASCII only!) across the area 
of any given heatsink of almost any convective design.  This is because 
the limitation is dissipation due to convection.  If you model the 
thermal path as a series string of resistances, the aluminum is very low 
resistance and the surface to air resistance is very high.

For more information visit our website!

Cheers & 73,

Howie
Pro Audio Engineering