Hi,
If a rig is being supplied from a DC source, what would you expect
if that supply was only giving the minimum specified voltage for the
rig. Would you expect full rated output power or would you only expect
that at the nominal supply voltage?
E.g. the IC746PRO is rated at 100W. The nominal supply is 13.8V +/-15%
The manual does not state what the power out is at the lower limit.
What have others measured?

Alan

"Alan Peake" wrote in message
...
Hi,
If a rig is being supplied from a DC source, what would you expect if
that supply was only giving the minimum specified voltage for the rig.
Would you expect full rated output power or would you only expect that at
the nominal supply voltage?
E.g. the IC746PRO is rated at 100W. The nominal supply is 13.8V +/-15%
The manual does not state what the power out is at the lower limit.
What have others measured?

Alan


Most ham rigs ( and many more "12 volt devices" ) are specified to put out
the designed power at 13.8 volts. This is a nominal voltage of a car with
the moror running. Any less voltage and you usually get lower output and at
a higher voltage you may get slightly more output.

There are always minor virations in the power output at the same voltage
from differant rigs of the same type. Most have a way of adjusting the
power output to a small degree to bring them back to the nominal power.

Ralph Mowery wrote:

Most ham rigs ( and many more "12 volt devices" ) are specified to put out
the designed power at 13.8 volts. This is a nominal voltage of a car with
the moror running. Any less voltage and you usually get lower output and at
a higher voltage you may get slightly more output.

There are always minor virations in the power output at the same voltage
from differant rigs of the same type. Most have a way of adjusting the
power output to a small degree to bring them back to the nominal power.



This is what I suspected but it was suggested to me that rigs are
designed with a good margin of power in mind so that they will give
rated output at the lower end of the supply voltage range.

I just fixed up an IC746PRO and found that at 13.2V, I only got 70W
instead of 100W. Then I found a drop of 1.3V in the factory supplied
leads (4m long). Shorter leads put this up to 80W but still short of the
rated output. I run all my radios on batteries and don't have a proper
13.8V supply so I don't know if the 746 is working to spec or not.

Alan