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

"Nathan Young" wrote in message
om...
Do you know if the WxWorx software has provisions to accept an NMEA
GPS input from a serial port? It would be nice to see the weather
displayed track-up and relative to present position.

Yes, it does indeed have this provision.. that is an extra $100 or so as a
software feature. For most handheld GPS systems you can use the NMEA/serial
cable you normally use to update your GPS database.

--
Richard Kaplan, CFII

www.flyimc.com

An update the PDA version of Weatherworx (see www.navair.com) :

While I am extremely impressed with the laptop version (www.wxworx.com), I
saw the PDA version and I am not impressed. I find it difficult to get
enough data in range on the PDA to be useful for strategic purposes. In the
best case it would require a lot of button pressing or stylus work on the
PDA in-fligh to keep track of weather.

With the laptop version (which is cheaper than the PDA version by the way),
it is possible to get enough data on the screen so that you never need to
press any buttons or do any other adjustments.. set up the wires and
software before flight and then just look over to the laptop in-flight to
get updates each 5 minutes with no extra pilot workload whatsoever.. this is
really nice.

There are also two features on the laptop version which in many ways exceed
the abilities of expensive MFD-type weather datalink systems. First, it is
possible to click on any portion of the radar image and get an exact readout
of intensity from 0dB to 75dB; this is much better than the typical 6 VIP
levels we currently use in interpreting radar data.. .this could really help
to decide weather to fly in level 3 precip; there is a big difference
between 25dB weather and 50dB weather and anywhere in between. Second, it
is possible to click on the precip tops image at any point and get a readout
of the cloud tops at that particular point... these are very powerful
features to help interpret a radar image, and these features are not even in
$10K to $15K panel-mount weather datalink systems.

The only real downside to the WeatherWorx system is the wiring; I am going
to try to work out a briefcase with a large DC power supply which is totally
self-contained; I could then use this also in the car driving through
thunderstorms or precip to get a sense of what the radar images are telling
me.

Finally, WeatherWorx has said verbally at Oshkosh that later in the year
they are planning a reduced price subscription which will be "substantially
less than $49 per month" and which will include METARs, TAFs, and Nexrad but
not echo tops or lightnight or other advanced features.

--
Richard Kaplan, CFII

www.flyimc.com

"Ryan Ferguson" wrote in message
...

This would be a compelling reason for me to upgrade to a full-featured new
color PDA if it works well. My Palm VIIx is still pumping out the budget
wx, though.


See www.navair.com for details on the PDA product -- I tried it and am not
impressed; it is hard to get enough data on the screen for strategic weather
and there would be a lot of button/stylus work in-flight to use it
practically.

I think the laptop version (www.wxworx.com) is much more usable in flight.



--
Richard Kaplan, CFII

www.flyimc.com

Thanks. Now I just wish they would answer my email about
availability, pricing, and where to order.

-Nathan


"Richard Kaplan" wrote in message news:527867a3e5debdcaa47a43662d41a518@TeraNews.. .
"Nathan Young" wrote in message
om...
Do you know if the WxWorx software has provisions to accept an NMEA
GPS input from a serial port? It would be nice to see the weather
displayed track-up and relative to present position.

Yes, it does indeed have this provision.. that is an extra $100 or so as a
software feature. For most handheld GPS systems you can use the NMEA/serial
cable you normally use to update your GPS database.

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.

"Ray Andraka" wrote in message
...
I wouldn't do it with just a dropping resistor. The current on the data
plate
is typically the maximum current. Additionally, if you look at the
current over
time you'll likely find that it fluctuates rapidly, especially in a
digital
radio like the XM radio. Instead, your cable needs a voltage regulator.
This
can be as simple as a zener diode and a resistor if the power dissipated
is
small. A better regulator would be one that uses a switching regulator as
a
DC-DC converter. You can get switching regulator modules with 28v input
and one
of a variety of output voltages from a number of vendors. I'm sure
Digikey has
a few of these modules. You'd have to add a case, wires, a fuse and
connectors.

I use Datel DC-DC converters in current avionics designs.

Your other option is to add a zener diode to the simple resistor circuit,
but now I am out in Jim Weir land and I will now retreat. (run away

Casey Wilson wrote:

"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.

--
--Ray Andraka, P.E.
President, the Andraka Consulting Group, Inc.
401/884-7930 Fax 401/884-7950
email
http://www.andraka.com

"They that give up essential liberty to obtain a little
temporary safety deserve neither liberty nor safety."
-Benjamin Franklin, 1759

"Richard Kaplan" wrote

I bought at Oshkosh ($49) a rechargeable 12V battery with 7 Amp-hour
endurance and a cigarette lighter adaptor output. This can easily run my
laptop computer, XMRadio receiver, and GPS for way longer than my
airpalne's
endurance. It is one more thing to carry around, but this also makes the
devices completely portable and ends any worry I might have about
impedance
matching when connecting devices to my airplane's cigarette lighter
adaptor.

--
Richard Kaplan, CFII

www.flyimc.com


You got ripped off. You can get a 7 amp hour battery from Tower Hobbies
(RC supplier) for 20 bucks. Those jumper packs for cars also serve the same
purpose, for less money.

I like your idea, just not the implementation! g
--
---Jim in NC---