Variometer installation

I have a Pilatus B4 and wish to install an ILEC audio variometer. A
TE probe on the tail is not going to happen, for a number of
reasons. So I guess my choice is either a fuselage mounted probe, or
no probe at all..which I guess would give me an uncompensated
variometer. any advice for me, a rookie? Thanks, Bill

Earlier, wrote:

...So I guess my choice is either a fuselage mounted probe, or
no probe at all.

I recommend the fuselage probe. Ten dollars worth of parts and you're
good to go.

See Nicks and Johnson for the original idea and its refinement. This
article is pretty clear about it:

http://wcsa.org/docs/TEprobe.pdf

Also, see Sebald for an alternative installation that combines TE
probe and radio antenna:

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

Thanks, Bob K.

On Nov 26, 6:21 pm, Bob Kuykendall wrote:
Earlier, wrote:
...So I guess my choice is either a fuselage mounted probe, or
no probe at all.

I recommend the fuselage probe. Ten dollars worth of parts and you're
good to go.

See Nicks and Johnson for the original idea and its refinement. This
article is pretty clear about it:

http://wcsa.org/docs/TEprobe.pdf

Also, see Sebald for an alternative installation that combines TE
probe and radio antenna:

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

Thanks, Bob K.

Bob,

I like the idea of incorporating the Radio Antenna and TE Probe. Do
you still have some of the parts, as said in the article?

On Nov 26, 5:32 pm, wrote:

I like the idea of incorporating the Radio Antenna and TE Probe. Do
you still have some of the parts, as said in the article?

Yes, I've still got a couple of the antenna-length wands up at the
shop. I think I have a couple of the machined bases as well, but I
hold no particular confidence I could put hand to them, so you're
probably out of luck there. Easy enough to make, though.

Thanks, Bob K.

wrote in message
...
On Nov 26, 6:21 pm, Bob Kuykendall wrote:
Earlier, wrote:
...So I guess my choice is either a fuselage mounted probe, or
no probe at all.

I recommend the fuselage probe. Ten dollars worth of parts and you're
good to go.

See Nicks and Johnson for the original idea and its refinement. This
article is pretty clear about it:

http://wcsa.org/docs/TEprobe.pdf

Also, see Sebald for an alternative installation that combines TE
probe and radio antenna:

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

Thanks, Bob K.

Bob,

I like the idea of incorporating the Radio Antenna and TE Probe. Do
you still have some of the parts, as said in the article?

This system was designed for a metal sailplane. You will need to create a
ground plane inside the fuselage of your Cherokee. Four 22 inch copper wire
radials should do the trick.

Wayne
HP-14 "6F"
http://www.soaridaho.com/
Amateur Radio W7ADK

right now i have a homemade ground plane antenna. It is made of
fairly stiff copper wire, which makes it tricky to fit behind the seat
in the glider. would it be equivalent to use some more malleable
copper, run along the inside of the fuselage, curved with the frame,
but still the 22-23 inch length that is important. any thoughts?

Thank you. I already have an antenna in place. I've read, over and
over, that fuselage mounted probes (particularly those mounted aft of
the wing - which, of course, is pretty much the only pace I'm going to
be able to put it) really stink compared to those on the tail. Shall
I infer from your comments that a ****ty TE probe is better than none
at all? Let me tell you that the intended purpose is for fun flying
in the vicinity of the airfield. There will be no cross-country to
speak of...mainly climbing back up to play around a bit. Mostly I
want this audio vario so I can generally tell up from down while
looking out of the cockpit.

On Nov 27, 8:09 am, wrote:
...I've read, over and over, that fuselage mounted probes
(particularly those mounted aft of the wing ... really stink
compared to those on the tail...

I think this is one of those "sure, it works in practice, but does it
work in theory?" topics.

As I've cited earlier in this thread, both Nicks and Johnson agree
that fuselage-mounted probe can be perfectly adequate. My experience
building, installing, and using the Sebald/Nicks antenna/TE probe for
a dozen years correlates what they've written on the topic.

I'm not particularly opposed to tail TEs, and I agree that they can be
more accurate. We plumbed our last three fuselages for them. But
unless a) (preferred) you're working on your fuselage on the half-
shell, b) the ID of your aft fuselage substantially exceeds the OD of
your body, or c) your ferret is trained on AC43.13 plumbing strain
relief, the slight accuracy advantage of the tail TE is likely not
worth the trouble of installing the necessary plumbing.

Thanks, Bob K.

wrote:
Shall
I infer from your comments that a ****ty TE probe is better than none
at all?

Yes, definitely.

I have a fuselage mounted TE on my glider, and I'm pretty sure I have a
slight leak (to be fixed this winter). Even so, it's far, far better
than none at all.

Without TE, you pull back on the stick and the vario cries "lift". Push,
and you hear "sink". Even local soaring, this will have you confused
enough to be back on the ground faster than you intend.

Having once flown a club glider with defective TE, so that in practice
it was completely uncompensated, the only way I could soar it was to
turn off the audio and fly by the seat of my pants, looking at the
needle only when established in a circle at a steady airspeed.

On Nov 27, 2:11 pm, Chris Reed wrote:
wrote:
Shall
I infer from your comments that a ****ty TE probe is better than none
at all?

Yes, definitely.

I have a fuselage mounted TE on my glider, and I'm pretty sure I have a
slight leak (to be fixed this winter). Even so, it's far, far better
than none at all.

Without TE, you pull back on the stick and the vario cries "lift". Push,
and you hear "sink". Even local soaring, this will have you confused
enough to be back on the ground faster than you intend.

Having once flown a club glider with defective TE, so that in practice
it was completely uncompensated, the only way I could soar it was to
turn off the audio and fly by the seat of my pants, looking at the
needle only when established in a circle at a steady airspeed.

heh the funny thing is that my longest flight was without TE or
audio. of course i guess i have a seat of the pants glider. and
flying at a steady speed is important.