In article ,
David G. Nagel wrote:
wrote:

When looking for a power supply for my Alinco dr-590, what type of
power supply would I look for? The radio says 13.8 v dc but if I get a
12 volt power supply will it put out the same wattage at the radio?

12 VDC to 13.8 VDC are nominal voltages. Very few radios are sensitive
to variation of voltage as long as the power supply can supply the amps.
The Icom 706 series seem to be sensitive to .LT. 12 VDC. I can't speak
to the Alinco.
Generally the front of any given power supply will say 12 VDC but the
specs will indicate 13.8 VDC.
No, if you provide 12 VDC you will output a lower wattage regardless of
the capacity to provide adequate amperage.

OK. When the meter lamp in my Kenwood TS-430S burned out recently,
I substituted a 12V replacement from Radio Shack. So, are bulbs
rated the same way? Certainly, it would appear auto bulbs are,
but what about wheat lamps?

Rob

In radio shacks case, I think they may mean 12 actual volts, being as
their
bulbs usually don't last very long when used with a 13-14 v supply...

Add a resister to lower the voltage, if you want it to last
longer...better yet..
convert to white LEDs...My 706 has those things...Maybe changing those
dang bulbs
will become a thing of the past...MK

"Rob Stampfli" wrote in message
...
In article ,
David G. Nagel wrote:
wrote:

When looking for a power supply for my Alinco dr-590, what type of
power supply would I look for? The radio says 13.8 v dc but if I get a
12 volt power supply will it put out the same wattage at the radio?

12 VDC to 13.8 VDC are nominal voltages. Very few radios are sensitive
to variation of voltage as long as the power supply can supply the amps.
The Icom 706 series seem to be sensitive to .LT. 12 VDC. I can't speak
to the Alinco.
Generally the front of any given power supply will say 12 VDC but the
specs will indicate 13.8 VDC.
No, if you provide 12 VDC you will output a lower wattage regardless of
the capacity to provide adequate amperage.

OK. When the meter lamp in my Kenwood TS-430S burned out recently,
I substituted a 12V replacement from Radio Shack. So, are bulbs
rated the same way? Certainly, it would appear auto bulbs are,
but what about wheat lamps?

Rob

Small light bulbs live in a different world. For instance, many flash lights
use a bulb that is rated for a lower voltage than the battery. I have one
that uses 2 AA cells and a 2.4 V bulb. This makes it brighter, and if the
life of the bulb turns out to be 10 hours, that is inconsequential, because
10 hours of use is beyond the life expectancy of a flash light. You probably
should have bought a 14 V bulb, since you do care about bulb life.

Tam/WB2TT

"Tam/WB2TT" wrote in message
...

"Rob Stampfli" wrote in message
...
In article ,
David G. Nagel wrote:
wrote:

When looking for a power supply for my Alinco dr-590, what type of
power supply would I look for? The radio says 13.8 v dc but if I get a
12 volt power supply will it put out the same wattage at the radio?

12 VDC to 13.8 VDC are nominal voltages. Very few radios are sensitive
to variation of voltage as long as the power supply can supply the amps.


The 'nominal' 12 volts is the voltage of the 6 two volt cells of a typical
auto battery, during normal discharge.
That is two volts per cell.
To charge a typical lead/acid battery a voltage of about 2.3 volts per cell
is required.
Therefore 6 x 2.3 = 13.8 volts.
Controlling to 13.8 volts is the job that the 'voltage regulator' does in an
automobile. To avoid overcharging and/or ruining the auto battery.
Therefore equipment which is designed to operate on nominally 12 volts is
usually designed to operate over the range 13.8 volts down to the point
where that battery is just about flat, at anything less than 12 volts. (If
your battery reads less than say 11.8 volts it's either shot or fully
discharged; BTW voltage is not a good indicator of whether or how well a
battery is charged!).
Large administrations e.g. AT&T, 'float' their large expensive battery
installations at around 2.15 to 2.17 volts per cell to offset 'local
chemical action' which causes batteries to slowly lose their state of charge
over time. For example 6 x 2.16 = 12.96 volts. This ensures the batteries
are fully charged at the start of a power interruption.