Introducing iOptron’s Compact Next-Generation German Equatorial Mount: The GEM28
Like its predecessors, the GEM28 is designed with portability in mind. Weighing in at only 4.5 kg (10 lbs), it supports up to a 12.7 kg (28 lbs) payload—an incredible 2.8 payload-to-mount weight ratio. This efficiency is achieved using design methods developed to reduce mount mass in iOptron’s renowned CEM family of mounts. The German EQ version caters to astronomers who prefer a traditional mount design and need reliable operation at higher latitudes.
Building on the legacy of earlier GEM models, new features enhance convenience and functionality: a positive-lock gear engagement system (easy to operate even while wearing gloves), built-in Wi-Fi for wireless connectivity, and recordable Permanent Periodic Error Correction (PPEC). Equipped with the GOTONOVA® GOTO technology and a 212,000-object database, the GEM28 sets a new benchmark for compact GOTO mounts.
This package includes an AccuAlign™ optical polar scope for fast polar alignment, a heavy-duty LiteRoc stainless steel tripod, and a custom die-cast aluminum hard carrying case.
Key Features
- German Equatorial Design: Latitude adjustment range from 10° to 70°.
- High Payload Capacity: Supports 12.7 kg (28 lbs) with a mount head weight of just 4.5 kg (10 lbs).
- Precision Tracking: Low periodic error (< ±12 arcsec) with PPEC support.
- Advanced Connectivity: Built-in Wi-Fi, USB port for computer control (ASCOM), and ST-4 autoguiding port.
- LiteRoc Heavy-Duty Tripod: 7.5 kg (16.5 lbs) stainless steel tripod with 44.5 mm (1.75 in) upper legs and 38.1 mm (1.5 in) lower legs for superior stability.
- Included Accessories: Custom aluminum carrying case, 4.5 kg (10 lbs) counterweight, and Go2Nova® 8409 hand controller.
- Box #1 (Mount Head & Case): SKU G282B — Gross Weight: 15.4 kg (34 lbs), Dimensions: 43.2 x 38.1 x 22.9 cm (17 x 15 x 9 in)
- Box #2 (LiteRoc Tripod): SKU 8283 — Gross Weight: 7.3 kg (16 lbs), Dimensions: 86.4 x 20.3 x 17.8 cm (34 x 8 x 7 in)
Detailed Technical Specifications
| Mount Type | German Equatorial Mount |
|---|---|
| Payload Capacity | 12.7 kg (28 lbs), excluding counterweight |
| Mount Head Weight | 4.5 kg (10 lbs) |
| Payload / Mount Weight Ratio | 2.80 |
| Structure Material | All-metal (Casting + CNC Machined) |
| Periodic Error (PE) | < ±12 arcsec (Permanent PEC included) |
| Worm Wheels (RA & DEC) | Φ88 mm (3.46 in), 144 teeth aluminum |
| Axis Shafts (RA & DEC) | Φ35 mm (1.38 in) steel shafts with Φ55 mm (2.17 in) ball bearings |
| Latitude Adjustment Range | 10° ~ 70° |
| Azimuth Adjustment Range | ± 6° |
| Polar Scope | AccuAlign™ Optical Polar Scope |
| Hand Controller | Go2Nova® 8409 with ~212,000 objects database |
| Maximum Slew Speed | 6°/sec (512x) |
| Power Requirement | 12V DC, 5A (100V ~ 240V AC Adapter included) |
| Wi-Fi & Ports | Built-in Wi-Fi, USB port, ST-4 Autoguide port |
| Counterweight Shaft | Φ20 x 200 mm (0.79 x 7.87 in) + Φ20 x 120 mm (0.79 x 4.72 in) extension |
| Counterweight | 4.5 kg (10 lbs) |
| Tripod | LiteRoc Stainless Steel Tripod, 7.5 kg (16.5 lbs), Height: 765 mm ~ 1168 mm (30 ~ 47 in) |
| Dovetail Saddle | 96.5 mm (3.8 in) Vixen-style, center adjustable |
| Operating Temperature | -10ºC ~ 40ºC |
* Recommended telescope optical tube diameter: under 152 mm (6 inches).
| Brand | iOptron |