Coronado PST Fine Tuning Ring Makes No Difference

[bendiddley]

When I turn the fine tuning ring on my PST it doesn't make any difference to the views. Whether it's to the left, middle, to the right or any where in between I can't see a noticeable difference. I thought it was meant to help reveal the subtle details in the suns appearance, but I can't detect anything. Is my PST faulty? Or am I not doing something right?

[Peter Drew]

Could possibly have something to do with there being almost no detail on the Sun at the moment. Tuning varies the appearance of prominences and filaments, if there are any.    😀 

[bendiddley]

Hmm, good call, hadn't thought of that. Thought it would show some of the texture of the surface though, wouldn't that be there all the time?

[Paul73]

There are days where there is nothing to be seen. There should be some texture on most days.

To give yourself the best chance. Use a longish eyepiece (20-25mm). Focus to get a sharp limb. Then play with the etalon tuning ring.

Good luck.

Paul

[bendiddley]

Just now, Paul73 said:

There are days where there is nothing to be seen. There should be some texture on most days.

To give yourself the best chance. Use a longish eyepiece (20-25mm). Focus to get a sharp limb. Then play with the etalon tuning ring.

Good luck.

Paul

That's what I did. Maybe I'll gve it another go and see what happens.

[Rusted]

Check Gong-Ha first for large prominences before you go out.

GONG H-Alpha Network Monitor

Make it a favourite on your PC's or laptop's bookmark bar for quick and easy reference.
Then look around the solar limb for signs of the prom as you tune your PST collar.

The position of the Sun in the field of view may change the visibility of a prom depending on the PST etalon's own sweet spot.
I move the sun around the field of view once I find a prom for the best view against the darkest possible background.
I get the best prom views at exactly the same tuning position as maximum surface detail.
Yours may need a different tuning point for each.

Plan B. Still no change?  Check the little drive screw is still present under the rubber tuning collar.
Don't scratch your PST while lifting the ring gently with a fine screwdriver or [better] cocktail sticks.
Fierce adjustment by a weight lifter might have damaged the tiny drive screw.

Plan C.  If you get a very dull, dark or plain solar disk your ITF filter may be "rusted" over.
My secondhand PST was like this and produced worthless views until I bought a new one from Maier in the US.

http://maierphotonics.com/656bandpassfilter-1.aspx

[bendiddley]

5 minutes ago, Rusted said:

Check Gong-Ha first for large prominences before you go out.

GONG H-Alpha Network Monitor

Make it a favourite on your PC's or laptop's bookmark bar for quick and easy reference.
Then look around the solar limb for signs of the prom as you tune your PST collar.

The position of the Sun in the field of view may change the visibility of a prom depending on the PST etalon's own sweet spot.
I move the sun around the field of view once I find a prom for the best view against the darkest possible background.
I get the best prom views at exactly the same tuning position as maximum surface detail.
Yours may need a different tuning point for each.

Plan B. Still no change? Check the little drive screw is still present under the rubber tuning collar.
Don't scratch your PST while lifting the ring gently with a fine screwdriver or [better] cocktail sticks.
Fierce adjustment by a weight lifter might have damaged the tiny drive screw.

Plan C. If you get a very dull, dark or plain solar disk your ITF filter may be "rusted" over.
My secondhand PST was like this and produced worthless views until I bought a new one from Maier in the US.

http://maierphotonics.com/656bandpassfilter-1.aspx

Thanks. I'll try moving the sun in the field of view to see if that improves things. The screw is present and seems to be doing its job in moving the ring when I turn the ring. Don't think the ITF filter is rusted as the view is nice and bright, however how would I find out if it is rusted if I wanted to check? Also regards moving the sun in the field of view, this is actually very hard to do and another problem I'm having in that the slightest movement and the sun is lost from view, its actually very hard trying to get the sun in view as the field of view is incredibly tight even with a 25mm EP, not sure if that is normal or not?