>
>>I think what Rich means is 8-3 or 6-3. Either is overkill unless you
>> >>have an extremely long run.
>When one uses a resonant-choke filtered supply, I agree. With a
>capacitor filter, the peak current is 10x higher. This is a whole >nuther
>ball game. When I used to tune up the Plywood Box with a 30pps >tuning
>pulser, my wife could hear the #4 copper vibrating in the >attic. My
>neighbor told Edison that his porch light blinked. When I >first fired up
>the Plywood Box, I had an additional 1000v of anode >supply drop because I
>used code-approved #6 copper. #4 copper was the >fix.
The 3CX15000A7 box in use in The Great NorthWest uses 2/0 gauge power wire,
directly from the Electric Company service, from the power pole to the
transformer taps. Bolted directly to the top of the transformer. Power
output from that amp is app. 35Kw. When reported how many amps where going
to be drawn from the electric supply, the Electric Company would run nothing
smaller, and insisted on having the equipment in place so they could inspect
the transformer input, as well as have it bolted directly to the transformer
to minimize R loss.
I had the opportunity to run a 3CX10K in California, and we had to run 4
gauge wire from the service to the amp. Anything less, and the power feed
would be "warm" to the touch.
10 gauge wire is too smallish for a 30 foot run for a legal limit amp. Look
at the voltage at both ends with an 8877 running full output. Quality of
connectors can also be an issue, as well, since that is the point of maximum
resistance.
Bottom line: The power drop is inversely proportional to the amount of
money spent at your local Home Depot when wiring up the shack.
>>But to be safe you might want to consider 8-3 over 10-3.
>This is hardly a safety issue.
Resistance issue it is.. Either resistance to doing the math, or resistance
of the wallet to open up wide enough to do it right the first time.
Toll Free
cheers, Ed W3NR
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