This X-Y axis adjustable mount system lets you use the TeleVue TV-60 refractor as a superfinder on a Celestron or Meade Schmidt-Cassegrain telescope 8" or larger in aperture. It allows you to collimate the optical axis of the TV-60 precisely with the optical axis of the larger scope so that the two scopes are aimed at the same point in the sky.
Please refer to the close-up image above to identify the parts of the mount (click on the small image to display a close-up, if you have not already done so). The mount component labeled "Dovetail" has a long arm that fits into the X-Y axis adjuster (the block with the knobs attached at the left of the image). The end of the arm can be seen protruding from the lower left end of the X-Y adjuster. The X-Y adjuster bolts into the "Mounting Block," using the two labeled bolts seen protruding from the underside of the adjuster.
The part labeled "SCT Accessory Bracket" should be permanently installed in either of the two pairs of holes provided for finderscope mounting at the 10 o'clock and 2 o'clock positions on the rear cell of your SCT using the screws supplied with the SCT. The 50mm factory finderscope is usually mounted in the 10 o'clock set of holes and can either be replaced by the TV-60 or used as a straight-through supplement to the larger aperture TV-60 superfinder. The mounting block with the X-Y adjuster attached is then inserted into the SCT accessory bracket. The plastic knob in the SCT accessory bracket locks the mounting block (carrying the X-Y adjustable mount) in place. There is a safety stop-screw in the accessory bracket and a safety counterbore in the mounting block for security. Position the SCT accessory bracket on your SCT so that safety stop-screw is at the eyepiece end of your SCT telescope.
Removing the "stop screws" on the end of the TV-60 dovetail (and the "stop screw" on the X-Y mount's dovetail) lets you install the TV-60 on the X-Y mount's dovetail. Remember to reinstall the dovetail's stop screw for safety after the TV-60 is installed on the dovetail.
The large knob in the X-Y adjuster, labeled "Lock Knob," acts as a pivot for the 2 horizontal adjustment screws that move the dovetail with its attached TV-60 from side to side (only the adjustment screw nearest the camera is shown). The lock knob simultaneously acts as the lock knob for the vertical "jack screw" adjustment that moves the dovetail and TV-60 up and down.
By adjusting the lock knob and various screws while looking alternately through your scope and the TV-60, you can precisely aim the optical axis of the TV-60 at the same point in the sky at which your main scope is aimed. Removing the dovetail's stop screw quickly lets you remove the TV-60 for use on a photo tripod for terrestrial observing or casual astronomy when you don't have time to take your main scope outside. If the adjustment screws are not disturbed while your TV-60 is off the main scope, the TV-60 should be correctly collimated when it is again mounted on the X-Y mount's dovetail. If it is not, a few quick tweaks of the collimating screws will soon have it lined up properly again.
The X-Y adjuster/dovetail assembly portion of this system can be used on its own to mount the TV-60 on the ring mount of all TeleVue refractors, allowing this adapter to serve a double purpose. Alternatively, this mount is available at lower cost without the mounting block and SCT accessory bracket as part #TVXYA to use strictly on TeleVue scopes without this mount's dual purpose capability.
