Cambridge 302 -or- Borgelt B50 plus data logger

[Romeo Delta]

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

[Marc Ramsey]

"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

[John Galloway]

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

[tango4]

"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

[goneill]

I do not have any of these instruments but for my ASW20 I am putting a B50
in it
due to reliability issues with cambridge gear,at our field some praise some
curse
cambridge 50\50, I prefer 100% reliability and Borgelt gear seems to fit
this ideal
gary
"Romeo Delta" > wrote in message
om...
> 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

[Owain Walters]

I have a B50 and it is probably the best averager I
have ever flown with. It is reliable, acurate and very
easy to use. I have it linked to a PDA and a Volklogger
and the system as a whole is great. (It may also be
worth stating that I completely re-worked the tubing
when I bought the glider (there wasnt a problem Ian
but we re-did the whole panel!)). My only problem is
the 'push' noise. I hate the noise but to be fair it
leaves you in no doubt that you are at the wrong speed!

I have three mates who all run 302's in their glider.
Two have gone back to the dealer for repairs (one of
those has been back more than once) and the third person
is having problems. I dont want to slag off CAI instruments
because in general I think they are good but the 302
seems to have some issues.

Owain

At 09:36 26 May 2004, Goneill wrote:
>I do not have any of these instruments but for my ASW20
>I am putting a B50
>in it
>due to reliability issues with cambridge gear,at our
>field some praise some
>curse
>cambridge 50\50, I prefer 100% reliability and Borgelt
>gear seems to fit
>this ideal
>gary
>'Romeo Delta' wrote in message
om...
>> 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
>
>
>

[Andy Durbin]

(Romeo Delta) wrote in message >...
> 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

I have been flying with 302 for over 2 years and recently added a B40
to my panel. My previous glider had a Cambridge MNAV. I have had no
reliability problems with the 302. I did have a problem with the unit
being delivered with a bad recorder seal but that was fixed on my
schedule. I also lost a contest day because of a problem with the
download utility. That was promptly fixed by Cambridge.

The 302 indicator response, when set for 2.3 sec, is very similar to
the B40. It is a little hard to correlate the reading though because
of the unsusual +/- 180 scale on the 302. Initially I didn't like the
way the 302 responded but after half a season I found that my tripple
probe had been delivered with one passage almost completely blocked.
I also found that my static lines were kinking when the canopy was
closed. When I sorted out those problems I find the 302 indicator and
audio easy to fly and similar to the B40. I much prefer the 302 audio
to the B40, perhaps because of all the years I flew with the MNAV.

The recorder of the 302 is hard to beat. I sample every 2 seconds and
have space for lots of flights. Unlike some recorders it never needs
erasing and the current flight will always be recorded.

I use the gear and airbrake warning system of the 302. It works as
advertised and saves installing a separate buzzer.

No problem with installation and, as someone else mentioned, you have
the choice of electronic or probe TE compensation.


Andy

[Roy Bourgeois]

Sorry to say - but I've had bad luck with my 302 which was plagued from =
the beginning with the "bad seal" problem. This has been compounded by =
a bit of "musical chairs" as to who owns the company and warranty =
responsibility.

Also the "fully integrated" concept is a 2 edged sword. It fits in a =
neat little hole in the panel for sure - but when it's broken in flight =
(or needs to go for repair) you are without anything - no vario, no =
averager, no logger, no gps souce. In short :"zip"

The only thing I really trust is my winter mechanical!

Good luck

Roy.

[Andy Durbin]

(Andy Durbin) wrote in message >...

> I have had no reliability problems with the 302.


Correction - I had 2 temperature probe failures. The first during
initial installation and the second after a few flights. The 302 will
not boot up with a failed temperature probe connected. It will
operate if the failed probe is disconnected.

Both replaced under warranty but a pain to have to replace them.


Andy

[Romeo Delta]

Owain Walters > wrote:

>...My only problem is the 'push' noise.
> I hate the noise but to be fair it
> leaves you in no doubt that you are at the wrong speed!

Dear Owain,

Can one program the B50 to emit audio only when in lift?
Is there a choice of tones available?

RD

[Romeo Delta]

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

[John Galloway]

RD,

I would be delighted to find I am wrong but the 302A
we are using gives no indication of outputting a wind
calculation in its interaction with a variety of PDA
programmes that my partner has tried with it (althout
SeeYou Mobile seems to calculate its own circling drift
wind when attached to the 302A). Also he has corresponded
with Paul Remde (US agent for Cambridge and GN11 as
you will know) about this subject and I am sure he
would have been able to tell us if this was wrong.
I had a look at the 302A manual and it doesn't say
it calculates winds - but the 302 manual also has no
mention of wind calculation which it does do.

The 302 variometer calculates vector winds and not
circling drift wind. Take away the pneumatic inputs
and it has no way of doing this - even if the computer
hardware that allows the 302 to do this isn't removed
in the process of turning it into a 302A - which I
suspect it will be.

John Galloway

At 21:54 26 May 2004, 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.
>
>Can anyone verify this?
>
>RD
>

[Eric Greenwell]

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

[Steve Koerner]

RD: If you choose to go with the B50 (a very good instrument), I can
offer a B50 plus Volkslogger system at 75% of current price. This
system was removed from my glider which was sold sans instruments.
Both units are in perfect operation. The Volkslogger is the new
connector type. Email me direct. I can send photos if needed.
Manuals are provided.

Steve Koerner
Mesa AZ

[Paul Remde]

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

[Kevin Christner]

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

[Romeo Delta]

"Paul Remde" > wrote:

>...the software calculates wind speed and direction while thermalling.

Hi Paul,

Is GNII able to provide wind and/or ground speed info enroute?

Is any nav software able to do either?

Ray

[Eric Greenwell]

Romeo Delta wrote:

> "Paul Remde" > wrote:
>
>
>>...the software calculates wind speed and direction while thermalling.
>
>
> Hi Paul,
>
> Is GNII able to provide wind and/or ground speed info enroute?

As a user of GNII and a 302: if the GNII is connected to the 302, then
yes; if it's connected to "just a GPS" (like my Cambridge model 20),
then no.
>
> Is any nav software able to do either?

The nav software also needs the airspeed information, or heading
information (compass). Just a GPS input isn't enough to update wind info
while cruising.

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

Eric Greenwell
Washington State
USA

[Bill Daniels]

"Eric Greenwell" > wrote in message
...
> Romeo Delta wrote:
>
> > "Paul Remde" > wrote:
> >
> >
> >>...the software calculates wind speed and direction while thermalling.
> >
> >
> > Hi Paul,
> >
> > Is GNII able to provide wind and/or ground speed info enroute?
>
> As a user of GNII and a 302: if the GNII is connected to the 302, then
> yes; if it's connected to "just a GPS" (like my Cambridge model 20),
> then no.
> >
> > Is any nav software able to do either?
>
> The nav software also needs the airspeed information, or heading
> information (compass). Just a GPS input isn't enough to update wind info
> while cruising.
>
> --
> Change "netto" to "net" to email me directly
>
> Eric Greenwell
> Washington State
> USA
>

By "enroute" I think RD meant straight flight. To solve for accurate winds
without turning, you need four pieces of data: Ground Track, Groundspeed,
True Airspeed and Heading.

The first two are available now from GPS. True Airspeed can be obtained
with a differential pressure sensor and air temperature. A good heading
sensor is the tough nut. I notice that marine navigation vendors are
beginning to sell GPS based heading sensors using two antennas and receivers
in one box. They're expensive but, being pure electronics, the price will
likely come down

I know that reasonably accurate wind data can be computed if the glider
makes slight turns while gliding between thermals. However, after decades
of powered flight, I habitually make very straight glides and the accuracy
of the wind data becomes highly suspect. Super accurate wind info while in
a straight glider would be very helpful finding convergence zones.

Bill Daniels

[Eric Greenwell]

Bill Daniels wrote:

> By "enroute" I think RD meant straight flight. To solve for accurate winds
> without turning, you need four pieces of data: Ground Track, Groundspeed,
> True Airspeed and Heading.
>
> The first two are available now from GPS. True Airspeed can be obtained
> with a differential pressure sensor and air temperature. A good heading
> sensor is the tough nut. I notice that marine navigation vendors are
> beginning to sell GPS based heading sensors using two antennas and receivers
> in one box. They're expensive but, being pure electronics, the price will
> likely come down

I'm already carrying two gps units, but they don't talk to each other!
Maybe mounting a Garmin Geko on each wing tip, then combining their
output would give us a heading. Mike B ought to be able to do that with
his RS232 combiner box and a small mod to his flight computer software.

>
> I know that reasonably accurate wind data can be computed if the glider
> makes slight turns while gliding between thermals. However, after decades
> of powered flight, I habitually make very straight glides and the accuracy
> of the wind data becomes highly suspect. Super accurate wind info while in
> a straight glider would be very helpful finding convergence zones.

Glide Navigator II and probably other software can display the error
between measured headwind (using IAS and ground speed) and headwind
calculated from the vector wind in use. An error over +/- 2 knots is a
good indication the vector wind in use isn't valid anymore. If I care
about the wind, I'll update the vector wind calculation by deviating
from a straight course, or even making one circle.

It's not as good as a system using headings, but it works well most of
the time.

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

Eric Greenwell
Washington State
USA

[Steve Koerner]

Having received several inquiries regarding my B50 plus Volkslogger
that I am offering, I've put together an email packet of information
and photos. The price set is $1395 (well under 75%). If you would
like to receive this, please send an email to me directly.

Steve Koerner


(Steve Koerner) wrote in message >...
> RD: If you choose to go with the B50 (a very good instrument), I can
> offer a B50 plus Volkslogger system at 75% of current price. This
> system was removed from my glider which was sold sans instruments.
> Both units are in perfect operation. The Volkslogger is the new
> connector type. Email me direct. I can send photos if needed.
> Manuals are provided.
>
> Steve Koerner
> Mesa AZ
>

[Paul Remde]

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
>

[Kevin Christner]

"Paul Remde" > wrote in message news:<Tmxtc.2135$4A6.1123@attbi_s52>...
> 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.
>

Of course... any PDA program can calculate wind from the groundspeed
method. WinPilot, mCU, GlideNav, pStrePla, flyWithCE, free programs
like GPSLOG and Soaringpilot.

While having all that memory is nice, whether or not all that memory
is actually useful is completley up in the Air. I have a sample rate
of 4 seconds and this provides 16hrs on my colibri. Chances are, if
you don't download a flight right away you dont care too much about
it. The other disadvantage of the 302a that I see is that its panel
mounted.... you need a laptop or PDA to get the logs. With the
Colibri, Volkslogger, and SDI Posigraph, you can bring it home and use
your desktop, or take it to the scorer at a contest.

Kevin

[John Galloway]

I find the fact that our 302A is panel mounted to be
one of its main attractions (as long as you have the
panel space). We don't have wires to the rear or the
cockpit side to install. We never have to carry the
logger around and so won't drop it, forget it or loose
it. It takes a couple minutes to download the file
to my old 1550 with the free Cambridge Utility programme.
If my syndicate partner and I didn't have our own
PDAs we could leave the PDA with the glider and just
take the secure file home or to the scorer in the CF
card. I used to use a GPS-NAV and carry it back ond
forth like a Volkslogger or Colibri etc but I much
prefer the fixed mount logger.

Also the panel monted logger can be left sealed and
secured in the glider (e.g.with signed paper tape)
which saves the hassle of getting the OO to observe
and confirm the the logger was actually flown in the
correct glider - in the event of someone actually following
all the security rules for badge claims.

Each to their own.

John Galloway

At 13:12 28 May 2004, Kevin Christner wrote:

.... The other disadvantage of the 302a that I see
is that its panel
>mounted.... you need a laptop or PDA to get the logs.
> With the
>Colibri, Volkslogger, and SDI Posigraph, you can bring
>it home and use
>your desktop, or take it to the scorer at a contest.
>
>Kevin
>

[Paul Remde]

Hi Kevin,

I'm sure that some people will prefer a portable logger and some will prefer
one mounted in the panel. The 302A works best when mounted in the panel,
but there is no requirement that it be mounted in the panel. I flew with
mine stowed behind me today in an SZD Junior. There is no need to view it
in flight. I used double sized plastic tape to secure the GPS antenna to
the top of the 302A. I also attached a RAM base with 1" ball so that I can
mount it on the canopy in our club's ASK-21. It worked fine, but is a bit
clunky. Another mounting solution would be to put it behind the instrument
panel (not using a hole in the panel) - secured to another instrument.

As someone else pointed out in another posting, a portable logger is not as
nice for a syndicate because if someone takes it home for downloading it may
not be available for the other syndicate partners when they need it. That
is not a problem when it is mounted in (or behind) the instrument panel.

You say the Colibri logs for 16 hours at 4 second intervals. That is pretty
good - definitely acceptable. But the 302A can log for 25 hours at 1 second
intervals. That makes the 3D flight replay very smooth in StrePla - I like
that.

Good Soaring,

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

"Kevin Christner" > wrote in message
om...
> "Paul Remde" > wrote in message
news:<Tmxtc.2135$4A6.1123@attbi_s52>...
> > 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.
> >
>
> Of course... any PDA program can calculate wind from the groundspeed
> method. WinPilot, mCU, GlideNav, pStrePla, flyWithCE, free programs
> like GPSLOG and Soaringpilot.
>
> While having all that memory is nice, whether or not all that memory
> is actually useful is completley up in the Air. I have a sample rate
> of 4 seconds and this provides 16hrs on my colibri. Chances are, if
> you don't download a flight right away you dont care too much about
> it. The other disadvantage of the 302a that I see is that its panel
> mounted.... you need a laptop or PDA to get the logs. With the
> Colibri, Volkslogger, and SDI Posigraph, you can bring it home and use
> your desktop, or take it to the scorer at a contest.
>
> Kevin

[Mike Borgelt]

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