Lunt Pressure Tuner

Hello everybody!

I'm planning to buy a Lunt solar telescope 60 double stacked. Question: what's the difference between the telescope with pressure tuner and the standard non-pressure tunable?

Thanks

J Munoz

Jesus...Since no one has chimed in on this query, I will give it a shot.

Some "traditional" hA scopes tune to the proper bandpass by tilting the etalon. The etalon is the unit that is on the lens end of the telescope. By tilting, you can tune to see surface detail or prominences. The primary problem is you are limited as to how much tilt you can get before throwing light path too far off-axis. Tilting is usually accomplished by a thumb wheel and hinge assembly and has a very limited travel. In Coronado terms, this is what they call the TMax tuner. Also, as is the case of my SM90/BF30, it is difficult to reach the tuner from the eyepiece.

Lunt has invented the pressure tuner which has improved the tuning scene dramatically. Since the etalon is INTERNAL (i.e. not attached to the end of the telescope), it resides down by the eyepiece end of things. It is simply a piston that varies the pressure on the etalon, allowing for a significant amount of tuning. Also, this piston is easy to reset for various altitudes. For example, if I take my Lunt 60mm on an airplane with me, all I have to do at the destination site is to fully remove the piston and then put it back and I am ready to view.

Pressure tuning is the way to go. It took me a short while to get used to it, having always used a tilt tuner. The large knurled knob makes gripping it very easy, even when wearing gloves. The combination of this tuner and the fact that the Lunt etalons have no central obstruction make for some very enjoyable solar viewing.

Clear as mud, huh? 8O Hope this helps.