The Primary Instrument used at Grenville Base Observatory is a prototype OTA design which incorporates features which I have found to be desirable in an observatory class telescope. The basic structure is a Surrier-type truss cage to eliminate tube current problems which plague solid tube designs. The Primary mirror is a lightweight CONICAL design which has two advantages: the first is cooldown time is faster due to the mirror's lower mass. The second adavantage is the simiplified cell design. 9 or 12-point floating support is replaced with a simple central post and a retaining collar to hold the mirror in place. The OTA and Dall-Kirkham optics were obtained from Royce Precision Optical Components. Other features of the OTA are: Carbon fiber upper truss, extra-heavy aluminum lower truss, f18 optics for lunar and planetary work, 25% secondary mirror obstruction ratio, an 80mm finderscope, and a sliding tube counterweight (a little bit of astronomical history kindly incorporated into the OTA after Mr. Royce's work in restoring the Yale Observatory's famous GRUBB refractor). Since the above photo was taken, a 127mm Maksutov-Cassegrain auxilliary OTA was added to the right side, a square light shield was added at the center frame of the truss, and a prime focus instrument anchor frame was added around the edge of the rear octagon backplate. The entire OTA assembly weighs in at around 115 lbs. Due to the open tube, lightweight mirror and the fact that the instrument is permanently installed, there is essentially NO cooldown time. The OTA rests very comfortably on a Software Bisque Paramount ME.
The Mak-Cas mounted on the right side of the main scope.
The secondary instrument at Grenville Base Observatory, a 29-year old 10" Classical Cassegrain, is currently undergoing a facelift and modernization procedure. The f16 Coulter optics are held in a 9-point Novak cell. The Parks fiberglass tube, Novak spider and tube counterweights sit atop of one of the last production heavy-duty Cave Astrola Mounts. The mount has 1-1/2" shafts and a tangent-arm electric declination drive. The photo to the right is the "before". The wide angle nature of this photo makes the mount seem slightly larger than it actually is.
Two other scopes can be found around the house: A Meade 80mm f15 refractor (circa 1980) on an Orion equatorial mount sits in the living room near the windows, and a 40mm Tasco 4VTE tabletop refractor sits atop a shelf in the library. The latter was acquired a few years ago online as a replacement for the long lost 4VTE of my childhood, which launched my interest in Astronomy xx years ago.