Lunt Pressure Tuner

First attempt on a you tube video and opening up the Lunt pressure Tuner as well.....Hope it helps someone...

[@spelunkerd]

It's too bad Lunt didn't make a video like this professionally. Problems and questions would be much easier to answer with some simple instruction, and of course they would be able to better control the discussion. In any case, thanks for going through this, it was worthwhile watching.

[@genoafire1]

Where are you using the scope if you are worried that sand might have gotten into the pressure tuner? Also, as others have said, you need to totally unscrew the cap upon initial use of the tuner, accordingly to the instructions, in order to adjust the pressure due to any altitude difference between your location and the manufacturing/final testing location in Tucson, Az.

[@SunlitEarth]

you're only talking about +/- 3 psi. Your not pumping up the hydraulics on a jet landing gear, man. Scratches on the brass and dirt on the threads is irrelevant as they are not part of the sealed systems. The main thing is that you have the proper amount of grease on the rings and that the rings themselves are fresh Lunt will replace the rings for nothing if you ask them. Advising anyone to take the brass cylinder out is a really bad thing to say as it would void the warranty and destroy the telescope.

[@barronredneck]

Those seals can be purchased at a hardware store. Their common on a lot of devices and over time wear out.

[@MountainFisher]

Auto parts store has a huge assortment of O-rings.

[@tectorama]

It's a very good scope. Just need some solar activity

[@rcj4046]

Thanks for posting. Did you ever solve the problem, and if so, what was it?

[@murph072278]

The instructions say that you are supposed to take the nob off all the way before using it for the first time, that could have been a problem as well.

[@NickHartman]

umm wait a minute...so this guy has never had the cylinder off the the tuner? You are supposed to do that everytime before you use it to equalize the pressure to your viewing site's atmospheric pressure according to Lunt's instructions...hmmm

[@marsaspen-murray3797]

My thoughts exactly. He is doing it wrong.

[@MrMa1981]

Doesn't deserve that scope.

[@kaibroeking9968]

Rather disappointingly simple setup. I had expected some bellows since I thought the etalon to be filled with either pure nitrogen, or buthane, or at least dry air. This also means that the pressure in the etalon housing will be just around atmospheric pressure. Careful with the clearances on those o-rings, though: they only form a good seal if they have the right amount of play on both sides in a groove which is precisely of a specified depth, so that they will be squeezed to the correct shape in the assembled piston-cylinder setup. One cannot just put a kitchen-sink gasket in an existing grove and hope for a tight seal. There are tables for these measurements provided by the manufacturers of the o-rings. As for the tuning itself: According to the Gladstone-Dale equation, the refractive index of a gas is proportional to its density, and therefore to the pressure inside the etalon. This holds good for small variations of pressure. Since the pressure changes like the inverse of the volume of the chamber, my first guess is that the central wavelength of the etalon shifts linearly with the rotation of the adjustment knob. Anyway: I am making a Fabry-Perot myself, and this little example has put my mind at rest as to the complexity of engineering required for a pressure fine tuning system ;-) Thanks for the vid.

[@StargazerFS128]

Kai Broeking And don't forget the inverse resonance of the spectral anomalies created by the oscillations of sub atomic particles as they are subjected to friction due to wave distortions in the outer most electron shell of hydrogen atoms. This may cause the telescope to suddenly reach critical mass triggering an atomic fission event causing the whole telescope to dematerialize in a blinding flash, as atoms suddenly split in a chain reaction not unlike a nuclear explosion, we don't want that to happen do we!?

[@kaibroeking9968]

Your time might have been better employed googling only half the terms you are using there instead of trying to write a funny put-down.