LX 5000, 7000, 7007 users - TE tube vs Electronic compensation question

I'd like to know if any long-timer user of these instruments has good data on the performance difference(s) between using the TE tube and the Electronic TE compensation, and if so, what you personally recommend.

(I seem to recall that the Cambridge 302 had a similar setup option, and that the electronic compensation worked very well.)

I currently have an LX 7007 Pro IGC (v1.2) with TE tube connection from the Schleicher multi-probe. However I'm getting very dubious speed command indications -- it always wants me to fly slow or slower, never faster, regardless of my polar, balast, or MC settings. I've been unable to resolve whether the problem is in the tubing between the analog unit and the probe, or something is wrong with the instrument.

I also have a Borgelt B-40 that is connected to the same multi-probe TE source. The B-40 seems to give the correct indications, and the Ptot plumbing seems to be fine as tested by blowing canned air at the tip of the probe and observing the ASI (excited) and B-40 (still). When I blow the air across the TE portion of the probe, the B-40 waggles and the ASI stays still, so I think my tubing is good.

So I'm wondering what the chances are that switching to electronic TE compensation, which simply involves connecting static pressure to the unit's TE input and changing the firmware setting accordingly, may fix the problem. (If nothing else, with this setup I could compare the B-40's pressure TE performance against the LX's electronic performance ...)

~ted/2NO

El martes, 26 de marzo de 2013 11:39:21 UTC-4, 2NO escribió:
I'd like to know if any long-timer user of these instruments has good data on the performance difference(s) between using the TE tube and the Electronic TE compensation, and if so, what you personally recommend.



(I seem to recall that the Cambridge 302 had a similar setup option, and that the electronic compensation worked very well.)



I currently have an LX 7007 Pro IGC (v1.2) with TE tube connection from the Schleicher multi-probe. However I'm getting very dubious speed command indications -- it always wants me to fly slow or slower, never faster, regardless of my polar, balast, or MC settings. I've been unable to resolve whether the problem is in the tubing between the analog unit and the probe, or something is wrong with the instrument.



I also have a Borgelt B-40 that is connected to the same multi-probe TE source. The B-40 seems to give the correct indications, and the Ptot plumbing seems to be fine as tested by blowing canned air at the tip of the probe and observing the ASI (excited) and B-40 (still). When I blow the air across the TE portion of the probe, the B-40 waggles and the ASI stays still, so I think my tubing is good.



So I'm wondering what the chances are that switching to electronic TE compensation, which simply involves connecting static pressure to the unit's TE input and changing the firmware setting accordingly, may fix the problem(If nothing else, with this setup I could compare the B-40's pressure TE performance against the LX's electronic performance ...)



~ted/2NO

Hi
I had a 5000 now have a 7000. Electonc TE is very good if you calibrate the total energy filter ,TEF, properly. Pitot and static are critical.Tube lengt is
important
Owner manual has a procedure easy to do in flight. My TEF is 7.
Good luck
S6