Sears "Discoverer" Model 4, 6305A 60 mm Equatorial Refractor Telescope

Here is Melanie with my vintage, circa 1967 Sears "Discoverer" Model 4, 6305A 60 mm Equatorial Refractor Telescope (focal length 900 mm, f15 optics). Purchased on eBay, it was in excellent condition optically and physically. The original price as shown in the Sears, Roebuck Fall/Winter 1967 catalog (see catalog page below) was $99.98, which in 2019 money is the equivalent of $763.49 (per the BLS CPI calculator).

There are a few minor paint scratches that I plan to repair. After disassembling all the mechanical parts, cleaning, greasing, and reassembling them, operation is very smooth. The sun projection screen will come in handy for the April 2024 total solar eclipse, and incredibly enough my house in Erie, Pennsylvania sits almost dead center in the path of totality.

The shipping / carrying case came with the telescope. It is constructed with a mahogany plywood top and bottom surface and with solid mahogany frame pieces. All the hardware was removed and either polished or painted. The wood was sanded just enough to get it smooth and remove a couple very minor scratches. I was careful to not erase any of the original already faded ink stamping on the inside bottom; it has "JAS," with the rest being Japanese. Then, three coats of semigloss polyurethane were applied, with sanding between coats. It restored to a beautiful finish. Finally, hardware was reinstalled.

Six molded styrofoam packing fixtures hold everything securely in place. I am surprised at the foam, thinking that being from the mid 1960s there would have been cardboard instead. I detest styrofoam.

A really nice lighted accessory tray is included. Fortunately, the original owner did not store AA batteries in the battery compartment, so there was not a bit of corrosion. A wipe with isopropyl alcohol shined the contacts and a little 409 took care of the rest. The articulated lamp uses a standard incandescent miniature bulb that is bright enough to be useful, but not light enough to reduce night vision.

The mahogany wood tripod is very sturdy and has a "Y" chain that connects between the lower portions of the lags to keep it more stable. The rubber ends (only two arrived with it) for the legs were decayed beyond restoration, so for now I just use the telescope with the metal points resting on the concrete.

Flexible shafts with knobs are provided for fine adjustment of the right ascension and declination axes. The declination knob on the shaft is useful, but I found for right ascension adjustment using the knob on the equatorial mount itself is more convenient. Therefore, the flexible shaft is not even installed.

I have never performed a precision polar alignment on this Sears "Discoverer" 6305A Equatorial Refractor Telescope, but instead just set the equatorial mount to roughly Erie's latitude (~42°) and point it at Polaris. For visual observation, that's good enough to track any astronomical object easily.

Three 0.975" oculars (eyepieces) were included with the telescope: 4 mm, 9 mm, and 24 mm, yielding magnifications of 225x, 100x, and 37.5x, respectively. They are not the highest quality - probably Huygens or Plossl types - but are plenty good enough for use with this grade of telescope. A 90° prism is included, along with a 2x Barlow magnifier and a terrestrial erecting prism (aka Porro prism). They do not exhibit excessive chromatic aberration and are reasonably focused at the edges. I do not plan to use the telescope for photography, and the moderately severe light pollution where I live makes this combination good enough.

My motivation for acquiring this telescope was two-fold: I wanted one for the sake of nostalgia, and I also wanted to help preserve one of these fine retail grade telescopes before they have all been relegated to landfills.

Speaking of retail grade telescopes, my daughter got a Celestron 60 mm equatorial refractor to keep at her house in North Carolina so I'd have something to use while visiting. Her skies are much darker than mine - the Milky Way is very apparent there. It is nearly identical to the Sears "Discoverer" Model 4 6305A in form, fit, and function, but the entire thing has nowhere near the quality of construction as the "Discoverer." The tripod is flimsy chinawood [sic], and the accessory tray is flimsy. The Celestron equatorial mount is physically smaller and is sloppier in operation than the Sears model. It works well enough, but is very noticeably of less overall quality. The image is pretty good, though. It has 1.25" oculars.

Having the Sears "Discoverer" Model 4 6503A Equatorial Refractor Telescope sitting on display with its mahogany case nearby is quite nice.

Here is information on the Sears "Discoverer" Model 6345, 90 mm Equatorial Refractor Telescope.

Posted November 16, 2019