Cambridge 302 -or- Borgelt B50 plus data logger

I am soliciting opinions on which is the best way to go:

1. Cambridge Aero 302

-or-

2. Borgelt B50 system combined with a data logger: a. CAI 302A
b. Colibri
c. Volkslogger

I would appreciate comments with consideration to ease of
installation, ease of use, performance (to include comments about
timing and accuracy of indication vs. actual conditions as well as
one's liking of the respective vario's audio tones), compatability,
reliability, factory support, etc.--especially from anyone who has
experience flying with both systems.

Add'l info: I intend to couple either system with a PDA using
GlideNav II. Also, I live in the U.S.

Thanks in advance,

RD

"Romeo Delta" wrote...
I am soliciting opinions on which is the best way to go:

1. Cambridge Aero 302

-or-

2. Borgelt B50 system combined with a data logger: a. CAI 302A
b. Colibri
c. Volkslogger

I've owned and used both, and have a few comments. As a vario I think the
B50 is a noticeably better instrument. It is responsive, has pleasant
audio, excellent factory support, and completely reliable. The downsides
are that it takes more panel space, some GPS sources are incompatible with
its multiplexing capabilities (but the listed flight recorders should work
fine), it is difficult to get the polar right for netto and speed to fly,
and changing the polar also requires opening the case, which makes it
unsuitable for gliders with multiple spans.

The 302 is a decent instrument, and the vario is a big improvement over the
LNAV and predecessors (don't believe the hype about it being less sensitive
to gusts, though). It has the option of using electronic total energy,
which is an advantage in some installations. The audio and meter response
times can be set independently. The polar can be changed by the PDA, it is
pretty easy to get usable netto and speed to fly. The MacCready and ballast
settings can be changed by the PDA or on the 302 itself, which means you can
use whatever is more comfortable to reach. The meter (and audio) can
indicate well over 20 knots, which is great for flying someplace like
Tonopah. The primary downside is that the servo-driven 360 degree meter is
slow, confusing, and hard to get used to. I also question the overall
reliability of the 302, as I know several people who have had to return
their units to Cambridge more than once for repairs, and several of the LCD
segments on my 302 are currently out. The "new" Cambridge also seems to
have lost the reputation the old one had for quick turn-around on service.

Marc

On Tue, 25 May 2004 13:00:32 -0700, "Marc Ramsey"
wrote:


it is difficult to get the polar right for netto and speed to fly,
and changing the polar also requires opening the case, which makes it
unsuitable for gliders with multiple spans.

I'll have to take issue with that and elucidate some of the design and
other points of the B50 seeing as some issues have been raised.
Some of these are of wider interest.

Yes, you do need to open the case (unless we've set the polar for you)
but you will likely do this only once.
We can supply the numbers for the polar if you give us the glider type
and the minimum flying weight of the glider i.e. glider, equipment,
pilot + parachute, no water. Or you can derive the numbers using the
B50polar.exe utility on our website. Please read the accompanying text
for for "how to instructions". Don't use Vne as the high speed point,
use the highest speed you would use for that weight. Don't use a speed
over the "knee" in the polar for standard class gliders.

The multiple span case isn't that hard to accomodate as the polar
difference is small and mainly at the low speed end and while
climbing. While climbing the netto and speed to fly functions aren't
active and the glider polar isn't used.
In straight flight the polar difference is at best about 0.2 knots
Not much more than a pointer width and pretty much irrelevant
operationally. In addition if you simply put in the polar for short
span the slightly lower sink rate at low speeds will mean the
instrument will correctly call for slightly lower speeds which makes
this calculation almost self compensating. In any case at low speeds
the sink vs airspeed is a very flat curve and small errors are of
little consequence. You can't fly that accurately anyway.

The ballast and bugs controls on the front of the B50 allow you to
adjust the polar in flight anyway. You may find your glider isn't
quite as good as the polar that is entered (likely as these are test
flown polars with gliders in excellent condition and clean, in smooth
air). Simply put in 5% bugs and this will likely fix things.

Late in the day if the wings are dirty you can adjust for this easily.
The control knobs mean that Macready, bugs and ballast are instantly
settable without scrolling through menus etc. The netto and speed to
fly both take the bugs setting into account.

I really haven't had too much feedback except of the " it works great
and I know what's going on for the first time " kind. Most seem happy
once the polar has been set once.

The vario now goes to +12/-10 knots on the indicator and +/-19.9 on
the averager and the audio doesn't saturate until at least +15 knots
so you can still center strong thermals.

Only two holes are required for installation. They can both be 57mm or
one can be 80mm for the vario indicator if you have the room. About
half the people seem to have room. No big deal to bolt one extra
indicator into a standard panel hole and plug in a D9 connector.
The display is clear and unambiguous with great contrast and high
resolution neither of which is necessarily the case with LCD type
pointers.

I'm always somewhat bemused by "easy installation". You install once
and use every time you fly. Does anyone seriously want to compromise
useability in favor of installability?

Not enough panel space? Take a look at the instrument panel photo I
took in flight (on our website). That is a Ventus A panel(the glider
is a Ventus C a 17.6 TOP). That is a transponder at the bottom, the
B40 is missing but there is still one spare 57mm hole and another 57mm
hole occupied by the engine instrument.

Someone mentioned the "fly faster sound". It is actually the same as
"fly slower" but the two tones are alternated much faster so it sounds
different. Recent B50's have an asymetric silent band for non zero
Macready settings. You don't hear the "fly faster" until you are
flying slower than than best glide for the air that you are in. This
means it isn't as annoying in gusty air. The visual indicator still
shows correct STF at all times. This is damped somewhat more than the
vario. Older B50's can be upgraded. The mod is very simple.

There is audio warning when you enter lift that is stronger than the
current Macready setting.

Custom configurations of the audio are available on special order but
I'd think carefully about requesting this as what is there is pretty
rational and just requires installation and connection to a good TE
probe, pitot and static to work very well.

We can supply a connector if you are connecting a GPS for retransmit
to a PDA or B2000, or the screw terminals make field installation
relatively painless.

No internal logger means you can choose your own favorite brand or use
a GPS engine or even a handheld GPS as GPS data source. The vario
doesn't go away for logger recalibration either.

There is of course nothing to stop you leaving your logger in the
aircraft and downloading it to a PDA instead of taking it away. Anyway
unless doing a badge or record flight or in a contest requiring IGC
loggers all the PDA programs have flight loggers built in as does the
B2000. If you fly cross country only for your own satisfaction or
practice and want to review your flights this saves considerable money
over buying an IGC logger.

A casual web search yesterday turned up a GPS mouse type device that
stores 15 hours of NMEA data at the one second rate. I'm sure there
are others. It is relatively trivial to turn NMEA data to IGC format
files. Seeing as it appears to be a sealed device if GPS altitude only
was allowed, simple OO procedures make this a low cost logger/GPS
source .(hint, hint)

We've been in the glider instrument business fulltime for 26 years
under the same ownership and management and that doesn't look like
changing anytime soon.

If you haven't already done so check out our website at
www.borgeltinstruments.com

There are some general knowledge and interest articles too.


Mike Borgelt

Borgelt Instruments

At 19:30 25 May 2004, Romeo Delta wrote:
I am soliciting opinions on which is the best way to
go:

1. Cambridge Aero 302

-or-

2. Borgelt B50 system combined with a data logger:
a. CAI 302A

b. Colibri

c. Volkslogger

I would appreciate comments with consideration to ease
of
installation, ease of use, performance (to include
comments about
timing and accuracy of indication vs. actual conditions
as well as
one's liking of the respective vario's audio tones),
compatability,
reliability, factory support, etc.--especially from
anyone who has
experience flying with both systems.

Add'l info: I intend to couple either system with
a PDA using
GlideNav II. Also, I live in the U.S.

Thanks in advance,

RD

RD,

I have had a Borgelt B100 in one glider, a 302+303+
GN11 (with Borgelt B40 backup) in another, currently
fly with a temporary 302A/GN11 combination with a B2000
in the post, and am awaiting a new glider for which
I have been going through the same questions as you
pose.

My experience of the Borgelt varios is that they are
great thermalling varios and ours have been very reliable.


The 302 vario was repeatedly unreliable (and is U/S
again in my ex glider at present) but the logger aspect
is excellent.

The 302A is fine but at present the interaction with
GN11 is limited by the fact that the 302A cannot calculate
winds and GN11 also does not do a wind calculation
when attached to a 302A as it seems to expect winds
as from a full 302. Paul Remde says this is on the
to do list.

I plan to have a B50/B2000 system in the new glider
using a small dedicated GPS unit to drive them - this
would be the main vario and back up logger (non approved
in the B2000). I plan a 302A as the main logger (independent
of the B50) and my 1550/GN11 can hang from the 302A
as the back up nav system. A B40 would be the obvious
back up vario choice to my mind.

This set up gives redundancy (definitely needed) but
takes up a lot of panel holes. It would be ideal if
the B50 were to be developed into a one panel hole
unit (hint). Alternatively, if a second hand one becomes
available at a good price I could take a chance on
another full 302 as main logger/ backup vario - thus
deleting the B40.

I don't plan to have a Volklogger or Colibri just because
I dislike all that stuff mounted along the cockpit
sides. Also the current Volklogger memory capacity
is a bit marginal and it needs to be emptied between
flights because it does not roll over.

John Galloway

"John Galloway" wrote in message
...
At 19:30 25 May 2004, Romeo Delta wrote:
snipped ........
I don't plan to have a Volklogger or Colibri just because
I dislike all that stuff mounted along the cockpit
sides.

So don't put it there! If you are using a PDA, bury the logger behind the
panel or behind the seat. There is no reason to have it on the cockpit side.

Consider an LX1600, colibri and a good PDA. A nice integrated package and
only one 57mm hole in the panel!

Ian
www.internationalsoaring.org/nimbus/IMG_2422.jpg

John Galloway wrote:

...the 302A cannot calculate winds
and GN11 also does not do a wind calculation when attached to a 302A.

Dear John,

I appreciate your considered response and don't mean to cast
dispersion; however,

Are you 100% positive that the 302A cannot calculate winds? This
seems odd for any GPS not to be able to do so.

Can anyone verify this?

RD

Romeo Delta wrote:

John Galloway wrote:


...the 302A cannot calculate winds
and GN11 also does not do a wind calculation when attached to a 302A.


Dear John,

I appreciate your considered response and don't mean to cast
dispersion; however,

Are you 100% positive that the 302A cannot calculate winds? This
seems odd for any GPS not to be able to do so.

It can't calculate winds during course deviations, like the 302 can,
because it doesn't have the airspeed measurement. It might be able to
calculate them while circling - don't know about that.

--
Change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

Hi,

I think there may some confusion on what the 302A can and can't do, and a
bug in Glide Navigator II. We recently realized that Glide Navigator II had
issues with the 302A (GPS/Logger) because it was confusing it with a 302
(GPS/logger/vario). Since the wind data was not being received from the
302A (as it would be from a 302) Glide Navigator II was displaying wind of 0
at all times. Today I tested the bug fix version of Glide Navigator II in
flight and it worked great with my 302A. The wind information was displayed
and looked correct to me. It should be available on my web site tomorrow
(Thursday) evening.

So, the answer to the question is that no, I'm pretty sure (but could be
wrong) that the 302A does not calculated wind speed and direction. But
using soaring flight software like Glide Navigator II or pocket*StrePla
(also tested today with my 302A) works great as the software calculates wind
speed and direction while thermalling.

I don't think Volksloggers calculate wind while circling either.

Does that make sense?

Good Soaring,

Paul Remde
Cumulus Soaring, Inc.
http://www.cumulus-soaring.com


"Romeo Delta" wrote in message
om...
John Galloway wrote:

...the 302A cannot calculate winds
and GN11 also does not do a wind calculation when attached to a 302A.

Dear John,

I appreciate your considered response and don't mean to cast
dispersion; however,

Are you 100% positive that the 302A cannot calculate winds? This
seems odd for any GPS not to be able to do so.

Can anyone verify this?

RD

If you are looking for a logger that calculates wind speed and
direction, the Colibri will do this and display it on the units
screen.

Kevin

If you are looking for a logger and Pocket PC system with a moving map and
reachable airports highlighted on the screen, Glide Navigator II and a
Cambridge 302A will automatically calculate and display wind speed and
direction. The 302A offers more memory for flight logs and waypoints than
any other logger. It is very nice to never have to worry about whether your
logger is going to run out of memory.

Good Soaring,

Paul Remde
Cumulus Soaring, Inc.
http://www.cumulus-soaring.com


"Kevin Christner" wrote in message
...
If you are looking for a logger that calculates wind speed and
direction, the Colibri will do this and display it on the units
screen.

Kevin