"And it's connectors" is quite true. I did some back of the envelope
calcs here and 60-75% of the voltage drop appears to be due to the
connectors + power supply sag.
This conclusion was drawn from a least squares linear fit of the V vs I
plot to obtain an effective R value. Then the cable resistance was
determined from wire cables. I collected a number of them from
people with different supplies, crimped and soldered PP's. These
effective resistance values seem to vary 50%-- perhaps a reflection of
power supply sag. We're talking total effective resistances in the 0.02
to 0.04 ohm range.
Draw you own conclusion whether or not it would be desirable to have a
lower resistance connector.
The calc's do indicate for a 5' cable, the difference between using 10
ga and 12 ga supply cable is negligible.
73 de Brian/K3KO
Dave G4AON wrote:
Doug, I guess you are seeing the Voltage drop on the power lead and it's
connectors. With my "not so old" Racal linear power supply, I obtained
the following results from the metering on the K3:
Zero out, 13.8V
5 Watts out, 13.5V
100 Watts out, 13.3V
This was checked into a 50 Ohm load on both 80m and 20m
73 Dave, G4AON
K3/100 #80
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