XMRadio Satellite Weather Has Arrived

"Richard Kaplan" writes:


3. I am convinced that the quality of the data is well worth it in a GA
cockpit, though I am concerned about the practicality of the various wires
and power connections in the cockpit. I think what I will do for myself is
to use the laptop-based version of the WxWorx system, buy a couple of A/C
inverters at Wamart with rechargable batteries, and try to put together my
own "weather datalink briefcase" which will contain my laptop computer, A/C
inverters, XMRadio receiver, and assorted wires; this should then work in
the airplane or the car (for learning purposes as I drive through
thunderstorms) or anywhere else... the ultimate "nerd bag" for a
weaher-addicted pilot. If anyone else does something like this, shared
details would be helpful.


Errr.. what exactly are you trying to run from AC?

My point being, if you have a laptop to run, you want a straight
DC-DC adapter to power it. Radios Hack sells same, (All I see now
is #273-1867, but there are others I think) as do various laptop
speciality houses. They typically come with a mating plug for your
laptop that not-so-incidently programs the output voltage.

With such, everything should run off the aircraft. You could add
a 2-4 AhH gelcell for independence, but that will build your
arm muscles..
--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

"David Lesher" wrote in message
...

Errr.. what exactly are you trying to run from AC?

Yes, you are correct... that would be better.. I do not have a cigarette
lighter adapter for my laptop but it would certainly be easier to buy that
then to deal with an A/C inverter.. the A/C inverter was suggsed by the
WeatherWorx engineer but as I thought about it you are correc it makes do
sense to go from D/C to A/C and then D/C with all the complexity involved.

--
Richard Kaplan, CFII

www.flyimc.com

I'm not sure I understand the discussion on DC voltage converters. I
currently have XM radio in my 28v plane, but the radio runs on 6 volts, so I
use an inverter to connect to the AC plug. Is it possible to get a 28v
cigarette lighter adaptor to cut the voltage to 6 volts directly? It would
be nice to eliminate the inverter.

The XM radio works great in the plane- CD quality stereo sound and over 100
channels with no drop outs in reception. It connected directly to my stereo
input.

Regarding weather, I'm waiting for Garmin to come up with an effective
interface with their 430/530, which is what they plan for the 1000. It'll
make the GDL 49 look like something from the stone age. The iPAQ/PC/GPS
combinations take a lot of wires and connections, as seen at OSH. Even the
Garmin reps admit that the GDL 49 left a lot to be desired.

How about satellite radio and real time weather all displayed on a Garmin
430/530 (the antennas are the same)?

"Viperdoc" wrote in message
...
I'm not sure I understand the discussion on DC voltage converters. I
currently have XM radio in my 28v plane, but the radio runs on 6 volts, so
I
use an inverter to connect to the AC plug. Is it possible to get a 28v
cigarette lighter adaptor to cut the voltage to 6 volts directly? It would
be nice to eliminate the inverter.

I'm not sure you will find one on the market. If you wanted to build it
yourself, you need to know the current flow in milliamperes (or amps) used
by the radio. That may be written on the ID plate or in the unit's specs.
For illustration, let's presume it is 150 milliamps. The supply voltage is
28 (actually closer to 32 without a load) so you need to drop 22 volts in a
resistor. You can calculate the required resistance by dividing the voltage
to drop (22) by the current flow (0.150) = 146.67 ohms. Round it up to 150.
Since it is going to dissipate energy in the form of heat, you need to know
the wattage or the product of current and voltage = 3.3 Watts. To be on the
safe side, you need to at least double that to 6.6 and round up to 10W. The
next safety feature would be an in-line fuse, but that's optional since you
can yank the connector out of the lighter socket.
Cut one of the pair of wires coming out of the connector and put the
10W, 150 ohm resistor in series. The typical night-light for the kid's
bedroom is 7.5W. Stick your finger up against one that has been on for a
couple of minutes and imagine about half that heat. That's what the
resistor is going to heat up to. The point is, keep your fingers off of it
when it's plugged in. Oh, that reminds me, don't wrap it up in foam -- the
heat needs to dissipate.