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My original posts on dismantling my PST were grouped around early February 2018:
https://fullerscopes.blogspot.com/2018/02/pst-dismantling-images-of-parts.html
You may need to move back and forth through several "chapters" of Older and Newer posts of that period to see all of it. Blogs normally update in reverse time.
Because so few people have seen the PST etalon dismantled I have photographed the various hidden parts. The inner workings remain safe from direct, physical contact if you proceed with the utmost care. No attempt to reach the active inner parts is desirable and certainly not shown here. History records that few etalons survive such "open heart surgery."
Removal of the etalon assembly from the PST gold tube requires a pair of sturdy strap wrenches. I almost broke mine in the desperate struggle to break the rock hard, red, thread locking compound. The trick is to have something useful left behind after the dismantling. A sledge hammer and cold chisel may be a lot quicker but leaves little to rescue for further use. Proceed with the utmost caution if you feel you really must copy my foolish example.I can well understand the factory wanting to secure the PST against "idiots" taking it apart. i.e. Those who feel "entitled" to be fully protected from all self-harm.
The light from the telescope objective enters from the right in this image. The AOK front adapter screws into the PST etalon and has a 2" push fit for standard 2" telescope focusers. The rear AOK adapter screws over the back of the etalon assembly. It has a female 2" socket for whatever follows.
Here is a view of the female side of the etalon beside the front adapter. The sharp eyed will note the glass in the AOK adapter. This is a Baader 1.125 GPC to bring my Celestron CR150 f/8 to f/10 to better suit the PST etalon. I promise to clean it before it all goes back together. The original PST was built this way and prefers f/10 for best performance. This is because the PST etalon consists of two lenses sandwiching the etalon itself. The etalon itself must see parallel light to function well. The optically weak, Baader 1.125 GPC does the job by stretching the focal length and resulting focal ratio to better suit the PST etalon + lens group.
Moving on: Here the knurled etalon tuning band has been pulled back. It looks like metal but is actually made of tough rubber. Note the cross-head screw protruding from the tape. This is the etalon drive screw and connects the inner and outer parts of the etalon. Lose that little screw and tuning becomes impossible. The PST probably wants to go into the waste basket. If only to avoid further torture at your hands!Drop the etalon onto concrete and your etalon is extremely unlikely to survive the fall. Unsurprisingly, PSTs aren't guaranteed against being dropped by "idiots." If you object to the term "idiots" then enter a more pleasing, PC term [for] yourself.
The knurled ring is placed carefully aside. We'll want this to go back on. So the tuning band can be used, as normal, when we put it all back together. 
Now take your watchmaker sized, cross-head screwdriver and remove that little screw. No need to remove the security tape. You are long past any hope of a Meade guarantee rescuing you from your own evil intent.Just poke about with the screwdriver until it seats firmly in the cross-head. Don't round off the cross-head socket or you can't dismantle the etalon any further. Press hard and the screw should unscrew. It may be small in diameter but it is surprisingly long.
The screw is actually dual-purpose. It's second trick, beyond driving the inner, etalon adjustment is holding the etalon shells together. Take note of the Teflon tape wrapping the inner etalon shell. Note the deliberate offset. If you cover the slot then the drive screw can't reach the inner arc. Where the magic happens when you tune your PST etalon.
SEE THE NEXT EXCITING EPISODE in Pt.5.
Click on any image for an enlargement.
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