varios not using a total energy probe

Hello! Can someone tell me which compensated varios do not need a
total energy probe? (no electronic compensation) Thanks a lot! Robert

Depends on what u mean by "compensated" varios.

There are three ways to achieve TE compensation, usually :
*Electronic via flight computer (which u ruled out, but also it isn't very
good, it needs VERY accurate pitot-static, among other problems),
*Diaphragm (old solution, and good only for the altitude it was calibrated
for)
*TE Probe (the simplest and most accurate one).

Both an all "mechanical" vario, or a new electronic one (the ones that
"beep") will require a TE probe to achieve the best results.
An old and very good diaphragm compensator used to be manufactured in the
70s by Wil Schueman, but like I said, it would be good only for the altitude
range it was calibrated for.
SZD also used to sell their gliders with cheap diaphragm compensators that
become brittle after a few years.
But I don't think they would be easy to find these days.

There's a reason everybody adopted TE probes : They are simple and the most
effective way to do it.



"Robert" wrote in message
om...
Hello! Can someone tell me which compensated varios do not need a
total energy probe? (no electronic compensation) Thanks a lot! Robert

Robert,
Bohli makes a taught band vario with a diaphragm compensator. Once very
popular in Europe, Don't know about now. Still available from Bohli, and
support service is excellent. Very expensive. Reichman's book tells you how
to make one yourself, I think.

Cheers!
"Robert" wrote in message
om...
Hello! Can someone tell me which compensated varios do not need a
total energy probe? (no electronic compensation) Thanks a lot! Robert

If you have a 3-way probe at the fin, electronic compensation will work
perfectly as the positioning of the static is very good and you can adjust
the proper compensation level in-flight.
--
Bert Willing

ASW20 "TW"


"Arnie" a écrit dans le message de
. com...
Depends on what u mean by "compensated" varios.

There are three ways to achieve TE compensation, usually :
*Electronic via flight computer (which u ruled out, but also it isn't very
good, it needs VERY accurate pitot-static, among other problems),
*Diaphragm (old solution, and good only for the altitude it was calibrated
for)
*TE Probe (the simplest and most accurate one).

Both an all "mechanical" vario, or a new electronic one (the ones that
"beep") will require a TE probe to achieve the best results.
An old and very good diaphragm compensator used to be manufactured in the
70s by Wil Schueman, but like I said, it would be good only for the
altitude
range it was calibrated for.
SZD also used to sell their gliders with cheap diaphragm compensators that
become brittle after a few years.
But I don't think they would be easy to find these days.

There's a reason everybody adopted TE probes : They are simple and the
most
effective way to do it.



"Robert" wrote in message
om...
Hello! Can someone tell me which compensated varios do not need a
total energy probe? (no electronic compensation) Thanks a lot! Robert

Bohli is what I was going to mention too. If the preceding message didn't
indicate, it is Swiss made. I think they have a website. I've heard very good
things about them and they're not all that exepensive since you can avoid the
cost of installing a TE probe.

Another item to consider would be an old era Ball vario. Some of them were
also internally compensated.

If you're merely trying to avoid the expense and trouble of fin mounting a TE
probe on an older ship, consider a fuselage mounted upright probe as used on
ASK-21s. They work just fine - especially if this would be for an older ship.

what you're asking is a bit confusing since you say "no TE probe" and also
"no electronic compensation"...
I think you are asking which Variometers will work "with just "Pitot/Static"
which will then be some form of "electronic compensation"...
First, let me say I'm often asked about which TE Probe is best for a
particular variometer, Though there are some probes that do work better
with particular gliders, if you understand that TE is purely a compensated
Static system you'll realize that the brand of variometer has little effect
on which type TE probe is used.....the variometer only "sees" TE compensated
static, or static as good as it is delivered to the variometer itself. This
being said, any variometer can work with normal "uncompensated "static", the
end result will then of course be "Stick thermals" without the TE balancing
act.

There is quite a list of variometers that have do work with electronic
compensation, in fact some going back to very early designs used this, some
not so well, some very well....
RICO VA and VAS were TE compensated while the VACS used Electronic TE
Many early "Richard" Ball variometers used "E" TE.....
Cambridge attempted this with MKIV Variometers
I'm sure there were others
most of the above had mixed results, usually not the best unless the user
had some intimate knowledge of the system and was willing to tinker
IMHO one of the best early "E" TE Vario's came from Westerboer, with the
VW910 then also other good systems from Zander, Peschges and others.
Almost all later "high end" flight computers have "E" TE available or allow
use of TE probes
Borgelt B100 and the SN-10 that came from this system can use "E" TE
Cambridge 302's can use "E" TE
All LX Navigation and Filser systems have excellent "E" TE and are easily
user configured in programming to adjust the compensation, I've used these
both with probe and "E" TE and been equally pleased with either set-up.
I'm sure there are others I have not mentioned
tim


"Robert" wrote in message
om...
Hello! Can someone tell me which compensated varios do not need a
total energy probe? (no electronic compensation) Thanks a lot! Robert

Earlier, (Robert) wrote:

Hello! Can someone tell me which compensated varios do not need a
total energy probe? (no electronic compensation) Thanks a lot! Robert

Just FYI, TE probes of the Nicks pattern are pretty easy to make. All
it takes is some brass tubing, a drill, and a plumbing solder rig. I
used to make a kit of parts for a Les Sebald-designed combination TE
probe and VHF radio antenna.

Here's a Web reprint of the 1981 Soaring article by Les. The only
thing I did different was to supply a machined 6061-T6 aluminum base
with a bayonet connector for the antenna cable:

http://www.soaridaho.com/Schreder/Co...E_ANTENNA.html

Thanks, and best regards

Bob K.
http://www.hpaircraft.com/hp-24

thanks for the information. to be more precise , I am using a
Schueman box which came with the ASW12 I bought years ago. I connected
the box to a normal winter vario (because I had only the box) and I am
very happy with the result. My other vario, the LX5000 has an
electronic compensation - works good (a bit slower then the Schueman).
I am now thinking about chaning my ASH26E to "NO TE probe"....

Robert wrote:
thanks for the information. to be more precise , I am using a
Schueman box which came with the ASW12 I bought years ago. I connected
the box to a normal winter vario (because I had only the box) and I am
very happy with the result. My other vario, the LX5000 has an
electronic compensation - works good (a bit slower then the Schueman).
I am now thinking about chaning my ASH26E to "NO TE probe"....

I changed my ASH 26E to electronic compensation several years ago. It
works just well as the TE probe did with my Cambridge 302. The problem
with the TE probe was the turbulence from the propeller made it
difficult to find and center thermals while self-launching.

You might want to join the ASH 26 owners group, where we discuss things
like this and many others, plus have an extensive archive. Check out

http://mail.serkowski.com/mailman/listinfo/owners

for info on subscribing.

And check out

http://mail.serkowski.com/ash26e/index.html

for a Schleicher ASH-26E Resources web site.

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

Eric Greenwell
Washington State
USA

On 16 Apr 2004 03:27:43 -0700, (Robert) wrote:

Hello! Can someone tell me which compensated varios do not need a
total energy probe? (no electronic compensation) Thanks a lot! Robert

While some people report good results with pitot/static TE your
results may differ. I wonder if thy've tested two identical varios
capable of being on pitot/static or TE side by side on the same
sources then on the different sources side by side. I've done this
with TE probes mounted in different places on the ship and got
interesting results.The gear doors are a good location for a TE probe.

Generally pitot and static probes/ports are much more sensitive to
sideslip than are good TE probes.(Good TE probe = Irving type two hole
probe )

You may have timing issues due to the distributed flow resistance and
capacitance of the sailplane plumbing.

Remember for pitot/static TE you are measuring two large signals and
subtracting them. Minor timing differences in the signals and small
non linearities in the measurement show up as large unwanted
transients on your vario.

These problems are mitigated somewhat by making the vario response
rather slow.(not what you really want)

I flew an ASW20 at Minden once which had a Schuemann box on a Sage
vario. The TE was OK but the thing was terribly slow compared to a
thermistor electronic vario with TE probe that was also fitted.

The problems of pitot static TE are solvable at some trouble in
installation and tuning but you are still left with the sideslip and
pitch sensitivity of the ports or probes. These can be solved also but
you end up with things like Kiel tubes for pitot and fancy static
probes which you then have to ask - what have you achieved?

The sensitivity of both TE systems to gusts is the same.

Mike Borgelt

Borgelt Instruments