Cambridge 302 versus new ClearNav vario?

Me, too! I expect my CNvXC tomorrow or Friday and I expect to connect
my Dell Streak 5 running XCSoar without difficulty using my K6BT. Yet,
I'm an eternal optimist!

Here are my thoughts on this particular combination based upon all that
I've read over the past week or so:

Start the Streak/XCSoar first. To that end, I found an Android app
which allows me to select program(s) to start at device boot up, ala the
Windows Start Folder. So, when I power on my Streak, XCSoar will start
automagically. After XCSoar is up, I'll apply power to the ship. I
haven't decided yet whether or not to install a separate power switch
for the CNvXC as it boots with power on.

I understand that I can no longer download and declare tasks from the
Streak to the CNvXC. Of course, I never did that any way with my 302 so
what's the loss? If I want to fly a real task, I'll simply select it
separately on each device.

The Streak starts with 0% bugs and the CNvXC starts with 100% clean. I
guess I'll just have to forget about bugs on the Streak and control that
function from the CNvXC. Not a big deal.

I should still be able to control MC and ballast via the streak. We'll
see... I've read that the Streak uses liters for ballast and I'll have
the CNvXC set up for gallons. I should be able to handle the difference
easily. IIRC, the 302 handled ballast as a percent of full. I could
press the "Dump" button on the Streak and it would count down remaining
water. The 302 would count down remaining percent. I liked that but, a
work around shouldn't be much of a problem.

To me the big problem is going to be with getting the polar just right.
I never bothered to do that with my 302 as I simply assumed that the
original purchaser did a good job. Actually, I found it to be more than
a bit optimistic causing me to fly a bit too slow on final glide. With
the ability to have multiple polars, I can now easily tune the polar to
achieve the desired result. I could probably have done that with the
302 but never got around to it. When I get a good (for my ship) polar in
the CNvXC, I'll then try the same numbers in the Streak, the goal being
to get them to present the same information.

I'm excited at the prospect.

On 1/6/2015 3:56 PM, Paul Villinski wrote:
Thanks for your input. I've done a considerable amount of research on the CNvXC in the last few days, and arrived at the conclusion that the inability to declare tasks directly from my Oudie is, in fact, the most significant drawback with the vario. However, I think I will only need to upload the task to the secure flight recorder in the CNvXC when I am making the occasional Badge attempt. Otherwise, I will just rely on the waypoints and task in the Oudie for navigation. I never bothered to upload waypoints into my 302. I gather it will be reasonably easy to load waypoints into the CNvXC via the USB stick, so that the basic navigation and glide slope to a point can be done by the device.

I queried ClearNav about the issue of loading/declaring task from a 3rd party device, and was told is that they will, at some point, enable this function. The question, of course, is when?

I also understand that the latest software which is being tested now does, in fact, employ the inertial sensors, and that improved gust filtering can be expected with the next software release. We shall see....

I have gone ahead and pulled the trigger on the new vario -- the timing argued for buying it now, rather than spending more money to repair the 302. It would have been preferable, of course, to wait till the product is "mature" and the software is fully developed, and I sincerely hope ClearNav will push ahead quickly on this.




--
Dan Marotta

Dan, when you are not flying records or similar things then it is not necessary to declare a task in your logger. That´s right! But it is also not necessary to put waypoints or tasks into your CNv.
XCSoar will handle the whole database, the waypoints and the tasks.

Normally, you select your task (or create a new one with the task editor) and activate it and than XCSoar handles your flight.
It calculates and shows your course and distance. It calculates your glide path with the necessary information (Distance, Polar, Wind, Bugs, MC) and it is able to calculate the best McCready.

And that is the only point, where polar-data, weight and bugs are necessary in your XNv. XCSoar is able to send the calculated or also manually modified MC to the CNv to influence the speed and to stay optimized on your glide-path.
If the polar, bugs or the wingloading in your CNv is not correct, the speed command mode will give you the wrong speed to fly.

If you use waypoints or tasks in the CNv it is (normally) only a kind of backup, because all these calculations e.g. the course to avoid an restricted airspaces are just made in your (main) flight-computer (Dell with XCSoar).

I never used my 302 or CNv as a navigation device, only as a backup for homing.

Good information, Alexander. That's exactly how I intend to use it.

I would like to have the same polar calculations in both as a backup so
I will spend my early time with the units getting the glide slopes and
speeds to fly to be as close together as I can. After that, it's all fun!

Dan

On 1/7/2015 11:46 AM, Alexander Müller wrote:
Dan, when you are not flying records or similar things then it is not necessary to declare a task in your logger. That´s right! But it is also not necessary to put waypoints or tasks into your CNv.
XCSoar will handle the whole database, the waypoints and the tasks.

Normally, you select your task (or create a new one with the task editor) and activate it and than XCSoar handles your flight.
It calculates and shows your course and distance. It calculates your glide path with the necessary information (Distance, Polar, Wind, Bugs, MC) and it is able to calculate the best McCready.

And that is the only point, where polar-data, weight and bugs are necessary in your XNv. XCSoar is able to send the calculated or also manually modified MC to the CNv to influence the speed and to stay optimized on your glide-path.
If the polar, bugs or the wingloading in your CNv is not correct, the speed command mode will give you the wrong speed to fly.

If you use waypoints or tasks in the CNv it is (normally) only a kind of backup, because all these calculations e.g. the course to avoid an restricted airspaces are just made in your (main) flight-computer (Dell with XCSoar).

I never used my 302 or CNv as a navigation device, only as a backup for homing.

--
Dan Marotta