The Decker-Grebner-Van Zandt Observatory
The observatory has two domes that house a 24-inch Newtonian Reflector and a 14-inch Schmidt-Cassegrain. The site was established in 1974, when PAS member Dr. Philip Holwick offered to donate his 12-inch Cave reflecting telescope to the Society on the condition that a suitable "dark-site" could be found for it. PAS members located an abandoned farmyard complete with several out buildings and a large concrete feedlot. The land was owned by the Forest Park Foundation, and use was granted for the PAS to develop an observatory. Mr William Rutherford of Forest Park Foundation not only granted the use of the land but also authorized funds to help the PAS develop the site. The 10-foot dome (foreground) had been built originally in the 1960's as one of the first fiberglass domes in the country. It was originally located at the Northmoor Observatory, but had fallen into disrepair and disuse because of the growing light pollution problem on the city's north side. Because of the problems in setting up the 14-inch telescope, the dome was moved, repaired, and re-installed to house the 14-inch telescope at the Jubilee site. In 1976, Dr. Sam Decker offered to purchase a 16-inch telescope and donate it to the Society. Society members Art Grebner and Rollin Van Zandt responded to Dr. Decker's offer by asking if he would be willing to donate the money to the club instead and let the PAS build as large a telescope as possible.
Art Grebner had built a dome outside his country home, but when he decided to move to the city, he had to do something with the dome, realizing the PAS needed it more than he did, he tore it down, and piece by piece reassembled it at Jubilee. Scott Swords, also a PAS member, donated the use of several pieces of earth moving equipment so that eroded areas could be filled in and the hill top leveled. The area was seeded with blue grass and buffalo grass to control insects and erosion. Finally in 1980, under police escort from Peoria, the 24-inch telescope was moved on its mount to Jubilee. In 1981, the original DC motors for controlling the telescope were replaced with stepper motors and encoders were added in preparation for adding the computer to control the movements of the telescope. Building the Decker-Grebner-Van Zandt Observatory and its telescopes have cost the Society in the vicinity of 10,000 man-hours. There is still more work to be done! The history doesn't end here...it begins... |
The Decker-Grebner-Van Zandt Observatory, otherwise known as "Jubilee" observatory, was built on the grounds of Jubilee State Park in an effort to escape the Peoria city lights. Over the years however, the city has been growing ever closer, and obscuring the night sky with light pollution.
Dr. Decker agreed, and work began on building the 24-inch Newtonian. The PAS bought a 24-inch Pyrex mirror blank and a 5-inch elipitcal flat. Art Grebner undertook the job of grinding the mirror, while Rollin Van Zandt began construction of the tube assembly and a horse-shoe mount. It took Art Grebner 6 months to complete the mirror grinding, sometimes resorting to power tools to remove the enormous amounts of glass. Rollin Van Zandt's task took over two years to complete. 
