iOptron GEM45-EC German Equatorial GoTo Mount with RA Encoder
iOptron GEM45-EC German Equatorial GoTo Mount with RA EncoderiOptron GEM45-EC German Equatorial GoTo Mount with RA EncoderiOptron GEM45-EC German Equatorial GoTo Mount with RA Encoder

About this product

Model:  iop_gem45ec_7603eca_1.75
Part Number:  7603ECA

Includes a high resolution encoder on the RA axis, new 'LiteRoc' 1.75" tripod & hard storage case. 

The GEM45-EC is the first of iOptron's next generation German equatorial mounts. 

Using experience gained during the development of their CEM series, iOptron have removed unnecessary weight resulting in a portable 7.2 kg / 15.8 lb mount with an impressive 2.8 payload-to-mount weight ratio. 

An integrated electronic polar scope (iPolar) makes polar alignment a breeze, even when the pole star is obscured.

Ultra-quiet stepper motors and a high resolution encoder on the RA axis provide precise pointing and low periodic error (<0.25 arc seconds rms). Large levers make it easy to engage the drive gears into place, even when wearing gloves. 

Integrated internal cable management means there is little chance of your cables becoming snagged and a new, patent pending, Universal Self-Centering Saddle (USCS) accommodates both Losmandy and Vixen style dovetail plates. 

Other features include computerised GOTO with a 212,000+ object library (includes star identification) GPS and Wi-Fi (requires optional iStarFi adapter).


  • Next generation German Equatorial Mount with high resolution encoder on RA axis
  • Realtime periodic error correction (RPEC)
  • Low periodic error (<0.25 arc seconds rms)
  • Precision stepper motor for precise GOTO and accurate tracking
  • Maximum payload of 45 lbs (20 kg) with a mount weight of only 15.8 lbs (7.2 kg)
  • Easy to use quick-lock gear clutches
  • Integrated iPolar electronic polar finder
  • Integrated cable management system
  • Go2Nova® 8407+ controller with Advanced GOTONOVA® GOTO Technology and built-in heater
  • Integrated ST-4 autoguiding port
  • 32-channel Global Positioning System (GPS)
  • USB communication port
  • Cable management system
  • New, patent-pending iOptron universal saddle
  • All metal, CNC machined with red/black anodized
  • Optional WiFi for mount control via SmartPhone/Tablet/Computer
  • All new LiteRoc 1.75" tripod with improved stability and leg locks
  • Hard case included

Go2Nova Hand Controller 8407

  • 200,000+ object database
  • 8 line, 21 character back lit large screen LCD
  • Low temperature operation as low as -20ºC
  • User friendly interface
  • 9 speed slew control with quiet mode
  • Large object database
  • Serial port for firmware upgrade

What's in the box

Supplied in two boxes. 

  • GEM45-EC mount head
  • CW shaft
  • 1x 5kg / 11lb Counterweight
  • GO2Nova 8407+ hand controller with cord. 
  • GPS Module
  • RJ11 Cable x2
  • RS232-RJ9 Cable
  • USB Cable
  • Alignment Peg
  • 1.75" tripod and accessory Tray
  • Hard Case


Mount German Equatorial Mount
Max payload* 45 lbs (20 kg), exclude counterweight
Mount weight 15.8 lb (7.2 kg)
Payload/Mount weight 2.78
Structure Material All metal, CNC machined
Exterior Finish Anodised red/black
Latitude adjustment range 14º ~ 68º
Azimuth adjustment range ± 6º
Tracking accuracy (PE)** <0.25 arcsec rms
PEC Real-time PEC (RPEC)
Period 400 sec
Worm diameter Φ17mm, Brass
Right Ascension worm wheel Φ110mm, 216 teeth, zero backlash
Declination worm wheel Φ110mm, 216 teeth, zero backlash
Right Ascension axis shaft Φ45mm steel
Declination axis shaft Φ45mm steel
Right Ascension bearings Φ68mm
Declination bearings Φ68mm
Counterweight shaft Φ28X280 mm, Stainless Steel (1.2 kg)
Counterweight 11lbs (5kg) X1
Motor Precision stepper motor, 1.8º/128X micro-step
Motor resolution 0.08 arcsec (200 PPS)
Transmission Synchronous belt
Hand Controller Go2Nova® 8407+, 8 line 21 character LCD
Star Database 212,000+, star identification
Power DC 12V, 5A
AC adapter 100V ~ 240V (included)
Power consumption 0.6A(Tracking), 0.9A(GOTO)
Power-down memory Yes
Polar scope Internal iPolar TM electronic polar scope
Meridian treatment Stop (0-20° pass), flip
Zero position Automatic zero search
Dovetail saddle iOptron Universal Saddle, 5"
Max slew speed 4.5°/sec (1080X)
Guiding port ST-4
Communication port USB
WiFi External (optional)
Cable Management DC12V (3A), ST4,USB
Tripod 1.75" Stainless Steel(~8kg), or optional Tri-pier
Hard case Included
Operation temperature -10ºC ~ 40ºC
Warranty Two year limited

* OTA size and length dependent
** Measured with encoder, 400 seconds

Downloads / Manuals


iOptron GEM45EC Quick Start Manual


Coming soon

iOptron Telescope ASCOM Driver:

Coming soon

Customer reviews

Average Rating (1 Review):  
Write a Review and share your opinions!

Rating (max 5):  
Robust-Good giding 6 month review
26 October 2021  | 

This has earned its keep. It has put in alot of guiding hors and it has just got on with the job in hand.Tonight guidng has been well < 1 rms averaging 0.7 most of the time.It also performs well with no guiding all, ive used it like that for 180 sec subs etc.I use this with ekos if anyone is wanting to se this outside of a windows platform .I have a C8 with a hyperstar and all my other gubbins as a payload.Probably best part of 15kg and it copes with it fine.I very pleased overall with this portable but sturdy mount.Looks cool too


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