This new iOptron ZEQ25GT balanced German equatorial mount has:
• Built-in dual-axis go-to computer drive with 59,000+ object database
• Built-in 32-channel GPS
• Periodic error correction and ST-4 autoguider port
• 27 pound maximum payload capacity
• Built-in illuminated polar finder scope
• Two-position counterweight shaft for operation at latitudes from 0° to 60°
• Adjustable height tripod with 1.5” diameter stainless steel legs
The new iOptron ZEQ25GT mount is a very portable and affordable German equatorial mount for entry-level and intermediate visual observers and astrophotographers. Its lightweight "Z-designed" mount balances the combined weight of the payload and counterweight directly over the mount's center of gravity. This allows for greater natural stability than conventional German equatorial mount designs. The mount head weighs only 10.4 pounds (4.7 kg) without counterweight, yet has a 27 pound (12.3 kg) payload capacity.
With its supplied AC and optional 12 VDC battery adapters, the iOptron ZEQ25GT is designed for both backyard imaging and transporting to a dark sky site. It is ideal for go-to visual observing and long exposure astrophotography with many of the most popular short focal length refractors and smaller reflector and catadioptric optical tubes.
Payload capacity: The ZEQ25GT comes with a 10.4 pound (4.7kg) counterweight capable of balancing loads up to 13 pounds (6kg). An an optional counterweight will be needed to balance heavier loads up to its rated 27 pound capacity. Most astrophotographers will probably want to limit the instrument payload to a maximum of about 18 pounds, to benefit from the increased stability of having a smaller instrument on an over-sized mount.
Drive system details: The synchronous toothed belt transmission ZEQ25GT has a 144-tooth 88mm diameter aluminum drive gears in both right ascension and declination. Brass worms are standard. The steel right ascension and declination shafts are 35mm in diameter, supported by 55mm diameter ball bearings. The spring-loaded gears have user adjustable loading force, depending on the payload. Gear switches in both RA and dec disengage the gears for easier load balancing,
The standard equipment dual-axis DC servo motors with encoders use a temperature-compensated quartz crystal oscillator controller to provide 0.14 arc second per step resolution, assuring an imperceptible stepping motion during visual observing and imaging. User-adjustable backlash compensation is standard.
The DC motors require a 12VDC (9~15VDC) power supply capable of providing a maximum 1.5A output. The motors draw 0.2A while tracking and 0.7A while slewing. There are nine guiding, centering, and slewing speeds available: sidereal and 2x sidereal for guiding; 8x, 16x, 64x, and 128x sidereal for centering; and 256x (1°/sec), 512x (2°/sec) sidereal, and a maximum speed of ~4.5°/sec for slewing.
The iOptron ZEQ25GT comes with an appropriately-sized 110VAC to 12VDC adapter. An optional 12VDC cigarette lighter plug adapter is available for use with optional rechargeable 12VDC battery packs, such as the Celestron 17 amp hour Power Tank.
The supplied GoToNova technology computer hand control has a built-in 32-channel GPS for accurate time and location acquisition when aligning on the sky. It has a more than 59,000 object go-to database that includes: 9 solar system objects (8 planets and the Moon), 60 named deep sky objects; the 110 object Messier Catalog, the 7,840 object NGC Catalog; the 5,386 object IC Catalog; the 12,921 object UGC Catalog; the 109 object Caldwell Catalog; the 400 object Herschel Catalog; 15 comets; 195 named stars; 210 double stars; 5,553 bright variable stars from the GCVS catalog; 26,584 bright stars from the SAO catalog; 15 comets; 116 asteroids; and the 88 modern constellations with their names; plus 60 user-defined objects.
The GoToNova hand controller has a 4 line/21 character display and backlit LED buttons. The mount is capable of operation in temperatures from 14° Fahrenheit (-10°C) to 104° (40° C). Volatile (non-permanent) periodic error correction (PEC) for astrophotography is built in. An ST-4 autoguiding port is built in. A serial port in the hand control, and a supplied RS232 to RJ9 serial cable, allows connection to a computer and the internet for firmware upgrades as well as mount control using optional ASCOM-compliant software.
Mount details: The ZEQ25GT’s innovative "Z-balanced" design mount puts the weight of the payload at the center of gravity, allowing greater natural stability and lighter weight — a nice benefit when setting up at a remote site. The equatorial head, not counting the standard equipment counterweight or tripod, weighs only 10.4 pounds (4.7kg) for the highest payload to mount weight ratio in its category.
The mount is designed to operate in both northern and southern hemispheres at latitudes from 0° to 60°. Twin adjustment knobs in the base of the mount let you fine-tune the azimuth alignment on the pole over a +/-10° arc. The ZEQ25GT mount has two latitude ranges: one for latitudes of 35º~60º and a second for latitudes of 0º~35º. The mount is set at the high latitude range (35~60º) at the factory. If you are observing from 35° to the equator, a few simple adjustments of the unique variable position counterweight bar lets you change the counterweight bar angle so the counterweight does not bump the tripod during use.
The standard equipment LED-illuminated polar alignment finderscope lets you align the scope on the celestial pole with very high accuracy, using a program built into the hand control. There is a built-in bubble level for leveling the mount for the most accurate tracking. A bright star alignment program in the hand control lets you polar align even when the pole is hidded by trees or buildings.
Tripod: The supplied adjustable height tripod has 1.5” diameter stainless steel legs, yet weighs only 11 pounds (5kg). A spreader bar, with built-in accessory tray, locks the legs firmly in place during use. It is very solid and stable, able to support the ZEQ25GT equatorial head and even its heaviest rated payloads with ease.
Optical tube mounting method: The spring-loaded mount head accepts industry-standard Vixen-style dovetails.
If you’re looking for a stable, high-precision, mid-capacity German equatorial mount – yet one that is very portable and reasonably priced – take a careful look at the new iOptron ZEQ25GT. It may be just what you are looking for.