AirTalk.org

googlebart2000@yahoo.com · Guest

For you instrument installation experts out there, I'd like to pick
your brain if you have a circular tuit.

My new glider (a Ventus 2C) came with a Sage (model CV) vario, Winter
ASI and altimeter, and nothing else that connects to pressure sources.
Last week a Cambridge 302 and a new LX7000 were installed.

When the new hardware was installed, all the tubing was replaced except
for the one from the capacity bottle (behind the pilot seat) to the
Sage, which is also connected to static pressure. No restrictor was
installed in the latter.

The C-302 and LX7000 were both installed on the TE source and
configured internally for TE (not electronic) compensation, so at the
time of my first flight Saturday, those were the only two instruments
connected to the TE probe.

The Sage was virtually useless during my two flights on Saturday (my
first in the glider). It swung wildly and rapidly in all directions.
The 302 and the LX seemed to work fine.

A fellow pilot suggested that I add a restrictor in the form of a
cigarette filter to the Sage's pressure source. The result yesterday
was very calm needle, maybe too calm (some of the filter will be
removed).

But I still found its reading to be quite different from the 302's.
Some to be expected, of course, since the Sage was on static source
while the 302 was on the TE. On light pull-ups, the stick thermals were
10 to 15 knots!

Anyway, all that's background. I want to switch the Sage from static
to TE pressure source so it acts more like the B-40 of my previous
glider (which was on the TE). But I have been warned not to put more
than one or two instruments on the TE pressure source, because they
have a certain amount of built-in "leak" or "loss" as part of
the PFM they do.

That is what I would like feedback on - if it's really inadvisable
to put 3 or more instruments on the TE. If it's a Bad Thing, my plan
will be to move the C-302 from TE to electronic compensation, and leave
the LX7000 with the Sage on the TE. Any thoughts on this too? ... or
should I put the LX7000 on electronic compensation too and leave the
Sage alone on TE?

Advance thanks

-ted/2NO

John Ferguson · Guest

This is a link to the Sage installation instructions

http://www.sagevariometers.com/sageinst.htm

Most people I know who have fitted a Sage Vario use
a restrictor, sometimes two in the TE line. Usual rule
is not to mixe capacity and pressure instruments on
the same TE line without seoarating them by at least
a couple of metres.

John

Kilo Charlie · Guest

"John Ferguson" <REMOVE_TO_REPLY.jcferguson (AT) grandfield (DOT) fsbusiness.co.uk>
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