Thanks for the various feedback.  I'll certainly give Aerox a look as
well as Mountain Air/High/Low, whatever.  Perhaps I need soma "O" at sea
level to think clearly.

Chuck,

 

I used to fly with a 22 cu ft tank strapped in the passenger seat (protection against turbulence, don't ask) and used an Oxymizer cannula.  Such cannulae are uncomfortable to wear during a long high altitude flight.  The bottle took up a lot of space. 

 

After an O2 deprivation experience, I obtained the Mountain High 8 cu ft tank (about 14" x 5") and the portable pulse demand system using the very small and comfortable cannula that MH supplies.  I built a bracket behind the pilot seat for holding the tank on the shelf formed by the flap actuator enclosure.  The tank is secured with velcro straps.  Even though the MH O2 controller can be battery powered, I do supply their optional power converter with aircraft power.  I have used the system on a variety of missions and the ones that stand out are trips across the Rockies to make the Redmond 100 at the factory Labor Day picnic.  MH is located across the street from Lancair and they have provided the chow on Friday nights.  They also refilled one's tank gratis.  These trips are always done between 14000 and 17000 feet to avoid the smoke from the ever present forest fires.  I find it hard to believe that I use only about a third of such a little tank after hours of flight at those altitudes.

 

Now I carry a spare cannula for a passenger, but since I have the solo system they get no O2 while donning the device, in spite of what they might believe.  It is much better as the passenger sleeps well and the XM delivered music is uninterrupted by needless chatter.  Interestingly, we both arrive at the destination rested and cheery.

 

Grayhawk