Extra Kollsman Altimeter Poimters

wrote in message
oups.com...
Well, I removed the innards and (independently) reset the reference
pointers to agree with the altitude hands at the correct Kollsman
setting. (I'm pretty handy at tinkering with delicate instruments.)

But I still don't really know what those little markers are for. If, as
you have suggested, they are used to set the altimeter to the correct
barometric pressure when the Kollsman window is blanked out, how does
one know where to set the markers? Let's say one is in an area where
the altitude-barometer combination there renders the Kollsman window
useless. If one is given the barometric pressure there, one would then
need a table or have to make a calculation to get the correct setting
for the reference markers. Does this sound correct?



Having read and re-read that article several times....

My latest take is that the correct position for them is
zero zero, when the Kollsman window set at 29.92.

From the article, they would appear to do nothing more than show the
estimated "difference" (not the "pressure altitude" as I first surmised, but
just the "difference").... the estimated difference between the *pressure*
altitude of the airport in standard-atmosphere conditions, compared to the
pressure altitude of the airport in the actual conditions of today. By
setting them to show that *difference*, your altitude readout will now show
the field elevation when you are on that field.

Left of zero would be negative (pressure altitude is less than standard,
i.e. actual pressure is higher than standard. Right of zero would be
positive, air pressure is lower than standard. ) The article mentions to
take care when setting negatives.... 900 would actually mean minus 100....


The only use of these markers would be if the station reported altimeter
setting in terms of this "pressure altitude variation", as depicted in the
diagram in the article. ( This seems to be something from a bygone era).
You would set the appropriate difference on the markers ( in the
appropriate plus or minus direction) and your altimeter would now be
adjusted correctly.....

Since pretty much everybody today reports the Kollsman value directly in
"inches of mercury" (or Millibars in Europe), you do that directly with the
Kollsman value, so the markers don't matter... you don't really care about
the "difference" any more.


So the only use today, would be... after setting the Kollsman window, you
could check a table .... or make a mental estimate.... of what the
difference should be ( about 100 feet per .10 inches of mercury away from
29.92).... Also, of course, that it is on the correct side of zero (left
side (negative) if greater than 29.92, right side if less than 29.92)....
and see that the markers correspond, as a double check.



After moving the markers to zero zero at 29.92, then setting your correct
altimeter setting, I would expect:

If, like 29.82, the indicators should show about plus 100, 29.72: plus200,
etc.
If, like 30.02: minus 100, 30.12: minus 200 , etc.

"Icebound" wrote in message
...


.... 900 would actually mean minus 100....



.... but the "thousands" pointer would be slightly left of zero....

In article ,
"Icebound" wrote:

My latest take is that the correct position for them is
zero zero, when the Kollsman window set at 29.92.

That is correct. If they do not, then something is mechanically wrong
within the instrument.

Jon,

Well I have a pretty good jpeg of the altimeter, but can't find the
email address for this group to post the pic to! Google says it's at
the bottom of the groups "Home Page", but I don't see it?

My groups tool (Netscape 7.0), using Google Groups, does not see
alt.binaries.pictures.aviation so I can't post there either. If you
send me your email address I'll send the pic to you. Or, if someone
knows this group's email address, I'll post the altimeter pic for all
to view.

Dennis

wrote:
Jon,

Well I have a pretty good jpeg of the altimeter, but can't find the
email address for this group to post the pic to! Google says it's at
the bottom of the groups "Home Page", but I don't see it?

My groups tool (Netscape 7.0), using Google Groups, does not see
alt.binaries.pictures.aviation so I can't post there either. If you
send me your email address I'll send the pic to you. Or, if someone
knows this group's email address, I'll post the altimeter pic for all
to view.

Newsgroups look like email, but they're not.

Instead of using the browser part of your Netscape 7.0, use the "mail and
newsgroups" part. It's the icon at the bottom left of your browser window that
looks like a US mail envelope, or it's the part of netscape that you use to read
email.

You might have to go to edit-preferences and configure a news server. If you
are using earthlink (as your return address indicates), use "news.earthlink.net"
as your news server. Then open the link for news.earthlink.net that is created
over on the left side of your mail and newsgroups window, click on "manage
newsgroup subscriptions" and subscribe to alt.binaries.pictures.aviation.

You might decide you want to use that to access this newsgroup, too, rather than
google.

By the way, you might want to disguise your return address when you post to
newsgroups, unless you like getting spam.

Dave

"Dave Butler" wrote in message
news:1120681100.317410@sj-nntpcache-5...
wrote:
[...]
My groups tool (Netscape 7.0), using Google Groups, does not see
alt.binaries.pictures.aviation so I can't post there either. If you
send me your email address I'll send the pic to you. Or, if someone
knows this group's email address, I'll post the altimeter pic for all
to view.

Newsgroups look like email, but they're not.

Instead of using the browser part of your Netscape 7.0, use the "mail and
newsgroups" part. It's the icon at the bottom left of your browser window
that looks like a US mail envelope, or it's the part of netscape that you
use
to read email.

Also, there are web services now available that will store files short-term
for transfer to other parties. They aren't a perfect solution for all
situations, and have no archive qualities (deletion of the files after a
week is common), but for quickly and easily moving files from one person to
another, they work fine.

One such service is http://www.dropload.com

For example, using the above service, upload the file, have notification
sent to yourself, and post the link here.

It's a much better solution than encoding binary files as text, even in a
newsgroup set aside specifically for that purpose (the text encoding, used
in email or in newsgroups, can add as much as 30% or so to the size of the
data being moved around...and of course, in the case of newsgroups, that
data gets copied to LOTS of places that will never actually use it).

Pete

Icebound,

Thanks for your interest and analysis. Allow me to digest it while I'm
traveling for a couple days.

BTW, a link to a pic of the altimeter should appear soon in this
discussion thread so that others can see the "extra" reference markers
the discussion centers on.

Dennis

To all:

Dennis emailed me the picture of his altimeter to post to my website
so that all can see it.

http://www.AirplaneZone.com/PubDir/Alt_002.jpg (135 KB)


David Odum - email: David at AirplaneZone dot com

Just from looking at the picture, I'd say the third needle is for 10,000
feet increments.

Look at how the labels line up when each pointer is in the 12:00 position...



"David Odum" MyFirstName@AirplaneZone wrote in message
...


To all:

Dennis emailed me the picture of his altimeter to post to my website
so that all can see it.

http://www.AirplaneZone.com/PubDir/Alt_002.jpg (135 KB)


David Odum - email: David at AirplaneZone dot com

Here's a modern Falcon Gauge unit with the same markings...

http://www.falcongauge.com/images/pr...sitiveALT1.jpg



"David Odum" MyFirstName@AirplaneZone wrote in message
...


To all:

Dennis emailed me the picture of his altimeter to post to my website
so that all can see it.

http://www.AirplaneZone.com/PubDir/Alt_002.jpg (135 KB)


David Odum - email: David at AirplaneZone dot com