With a name straight out of Greek mythology, where Nyx is the goddess of the night, the new NYX-101 is a harmonic drive mount from Greece-based Pegasus Astro.
We received the NYX-101 mount and matching Pegasus carbon-fibre tripod as a package and right away we were really impressed by the lightweight nature of both items and the quality of materials used, along with the attention to detail in the machining of the various components, even down to the locking power lead connector and easy-to-adjust alignment handles.
Both the mount head and tripod come with a protective carry bag, making them highly portable, with a combined weight of just 8.5kg.
A guide to telescope mounts
A huge benefit of harmonic drive mounts is that they don’t require any counterweight system unless you are using really heavy equipment, making them exceptionally travel-friendly.
In fact, there is no need for a counterweight or bar at all with loads of up to 20kg.
As it happened, new firmware for the mount was released just after we received our review model.
Pegasus Astro has a good reputation for ongoing improvement and support, and the upgrade was carried out by connecting the mount to our home Wi-Fi network.
Initial setup of the mount requires linking it to a PC via USB 2.0, but afterwards it can
be controlled wirelessly over its own Wi-Fi network, which has a reasonable range of a few metres.
We found the most stable connection was via USB, as our mobile devices had a habit of losing connection to the Wi-Fi, sometimes mid-slew – a shame, because controlling the NYX-101 with Sky Safari was most enjoyable.
Pegasus Astro provides the Unity control app for Android or iOS devices, and although it felt like a beta version, everything worked as it should.
A feature of the app is that the directional control buttons are configured to move the mount to north or south and so on, but in practice this meant the direction of movement on a particular button might swap with consecutive presses, depending on mount position, which we found a little annoying.
At first we configured the mount for equatorial use with a short 75mm refractor.
With a rough polar alignment and then a three-star alignment routine via the app, we were soon navigating to various objects.
The Go-To function for this widefield view was very accurate.
Before we tried something more challenging, we took the chance to try autoguiding.
A multi-use ST4 port is included that can be used for guiding or for a hand controller, but we took advantage of the ASCOM connectivity in telescope-guiding software PHD2.
The NYX-101 also offers INDI protocol and Sky Safari options with LX200 compatibility.
With a DSLR on the telescope and an off-axis guider, within a couple of minutes PHD2 was calibrated and guiding steadily, allowing us to take a few shots of January 2023’s green comet, C/2022 E3 ZTF, and the Orion Nebula.
The mount easily handled guiding to these objects.
To really test the limits of the NYX-101, we brought out our Celestron 11-inch EdgeHD, a large telescope that with its accessories weighs over 15kg.
It was not without some trepidation that we attempted the first slews with the scope in place.
It seemed an unnaturally big load without any counterweights balancing it, but we need not have worried.
The NYX-101 did not miss a beat, easily and accurately moving the mount between targets.
In altaz mode, with an accurate setup and alignment, the Go-To performance was excellent, allowing us an enjoyable mini Messier Catalogue marathon as we quickly hopped to various objects in the Unity app catalogue.
Ideal as a travelling mount and capable enough for permanent observatory installation, Pegasus Astro’s NYX-101 offers a modern, accurate and competitively-priced mounting option both for observers and astrophotographers.
Harmonic drive system
Rather than traditional worm-drive gearing, the NYX-101 uses strain wave gears on both the RA and dec. axes.
These mechanisms are typically used in manufacturing robots as they allow for very precise movements, high-torque loads and maintenance-free operation for many years.
Compared to worm-drive gears that are prone to backlash issues, strain wave gears offer much higher reduction ratios within the same-size unit.
For the NYX-101 this allows a high-precision 500:1 reduction on the all-important RA axis, giving a resolution of 0.10 arcseconds, while the less critical dec. axis works at 300:1.
In practice, the harmonic drive system delivers a lightweight mount with reliable and steady operation, particularly suitable for guided astrophotography.
Once the mount is pointed at the polar axis and a suitable star alignment procedure has been carried out, the precision and accuracy of the Go-To commands was impressive.
We found that even at 2,800mm focal length, the NYX-101 would reliably put the chosen object in the field of view of our 23mm eyepiece.
5 best features
Dual-mode operation
The NYX-101 is easily configured in altaz or equatorial mode with a simple adjustment between the two options. Setting the appropriate configuration within the Unity app is as simple as one click too, offering a rapid choice between a traditional altaz viewing session or a full-on astrophotography outing.
Connectivity
Communication between the mount and a PC is via a USB 2.0 cable and Wi-Fi. The NYX-101 connects to your home Wi-Fi network, a step that is necessary for updating firmware, as well as producing its own Wi-Fi signal which allows for wireless control via a laptop, mobile phone or tablet.
Universal saddle
The NYX-101 has a universal saddle for attaching your telescope to the mount, accepting both Losmandy and Vixen-style dovetail bars. The dual locking nuts held our equipment firmly, but we did feel that slightly larger knurled handles would have been easier to tighten one-handed while holding a telescope in place.
Tripod
The dedicated Pegasus Astro carbon-fibre tripod weighs a mere 2kg, but will support 15kg of gear for imaging or a whopping 50kg in total. The tripod is well-built and the legs easily extend and lock. The anodised components are reassuringly well-made, while a bubble level is included for basic levelling.
Padded shell cases
Both mount and tripod are protected from damage and dust when travelling or in storage with a custom-made padded case. The cases are large enough to contain everything associated with the mount and tripod, and compact enough for easy transport. In fact, we could easily carry both items in one hand.
Vital stats
- Price: £3,490 (mount £3,095; tripod £395)
- Mount type: harmonic drive dual mode (EQ/altaz)
- Load capacity: 20kg; 30kg with counter- weights
- Slew speed: up to 5° per second
- Power input: 12v DC (PSU included)
- Autoguider port: ST4
- Protocols: ASCOM, INDI, Sky Safari (LX200)
- Weight: 6.5kg mount; 2kg tripod
- Supplier: Widescreen Centre
- Tel: 01353 776199
- www.widescreen-centre.co.uk
This review originally appeared in the May 2023 issue of BBC Sky at Night Magazine.
