[Elecraft] KPA-1500 Power Supply Cable Size

[Jim Brown]

On 7/30/2018 6:43 AM, K8ZCT wrote:
> Speaker wire is made for speaker systems. Although it may look like "lamp cord" it is not listed for use to wire up a lamp.

Right -- it has to do with voltage breakdown of the insulation, which 
must be 3kV on the AC power line (in the case of a lightning spike).

It is my understanding that the KPA1500 operates at about 60VDC, and 
that cable is carrying 50-60A. There are no lightning spikes to contend 
with. All that matters is DC resistance, sufficiently robust physical 
construction, and voltage breakdown.

In large sound systems, power amps often produce voltage peaks in the 
range of 150V.

FWIW, the Red/White zip cord sold as speaker cable is often pretty lousy 
quality. Insulation is made very thick as a marketing measure -- to make 
it look "beefier" than it really is, and therefore worth more money. :) 
When I've measured some hamfest cables like this with a micrometer I've 
found that they're actually smaller than labeled!  In other words, we're 
getting cheated. :)

73, Jim K9YC