Australian Sky & Telescope — July 2017

http://www.skyandtelescope.com.au 67

SThe Evolution tripod includes a handy bubble

levelto quickly level the tripod before attaching

the fork mount. A central pin helps to centre the

fork base.

The set-up
The Evolution 9.25 ships in two boxes:
one containing the tripod, and the
other with the optical tube assembly
(OTA) attached to its single-arm fork
mount. The OTA box also contains a
hand control paddle, 40- and 13-mm
Plössl eyepieces, a plastic-bodied star
diagonal, a zero-power red-dot finder,
an AC adapter, and an instruction
manual plus an addendum sheet.
The Evolution tripod is a hefty
model with 5-cm-diameter stainless-
steel extendable legs equipped with two
metal spreaders. The upper spreader is
tightened against the tripod legs with
a knob on a threaded rod that extends
from the underside of the tripod head,
and doubles as an accessory tray,
while the other folds out near the leg
extensions to provide additional stability.
The combination of telescope and
fork mount weighs in at 16 kg and is a
bit awkward to handle, with the tube
being considerably longer than that of
Celestron’s 20-cm model. The scope is
easiest to set up by first removing the
OTA from the fork and assembling the
three parts in stages. The tube attaches
to the mount via a Vixen-style dovetail
bar and saddle, and is held securely in
place with a single knob. Most users
will mount the fork assembly directly
onto the tripod and use the scope
in alt-azimuth fashion as I did. An
optional wedge enables the telescope
to be used in equatorial mode for deep
sky imaging, and could also mitigate an
issue I discovered later on.
Lifting the light fork and its drive
base to the tripod isn’t a strain, but
getting the base properly positioned
on the tripod head can be. There’s a
central pin on the head that goes into
a hole on the underside of the mount’s
base. With practice, it became easier to
position the base properly onto the pin,
but it was never easy. Once the base is
properly positioned, the remainder of
the assembly is pretty straightforward.
After admiring the attractiveness of
the scope for a while, I took stock of the
accessories. Although most owners will
use the telescope with a smartphone

or tablet, Celestron includes the latest

version of its NexStar+ hand control.

Not only does it enable the telescope to

be operated without a smart device, it

enables control of the Evolution with a

laptop computer. But at first, it wasn’t

clear to me how that worked. The new

hand control doesn’t have a serial port

like previous models. Instead, there is

a mini USB jack, and I was afraid that

would make it impossible to use the

Evolution with my astronomy software,

which requires a serial connection.

I discovered, however, that the USB

connector on the hand control is

followed by an internal serial-to-

USB converter, and a laptop sees the

Evolution as a normal serial device.

The Evolution has a built-in lithium

iron phosphate rechargeable battery in

its base, and the included AC adapter

serves as its charger. The manual warns

that the battery must be charged before

using the telescope for the first time.

Unfortunately, it doesn’t explain exactly

how to do that.

A table in the back of the instruction

book clued me in. The Celestron-logo

power LED indicator on the fork arm

indicates battery charge, among other

things. Rapid blinking warns of a low

battery, while slow pulsing means

charging is in progress, and a steady

light means fully charged. Plugging the

charger into the power receptacle on

the telescope’s control panel resulted in

half an hour of LED pulsing before the

battery was topped off.

Under the stars

with SkyPortal

It was time to get the Evo into the

backyard, where the first challenge was

balancing the tube by sliding it back and

forth in the saddle with the attachment

knob slightly loosened. When the

telescope was perfectly balanced, its star

diagonal bumped into the base when

the scope was pointed higher in altitude

than about 70°. I could improve on

that 70° somewhat by moving the tube

forward in the saddle.

This minor imbalance didn’t cause

problems, but I was reluctant to use the

SOnce the drive base is seated, the fork is

rotated until alignment marks line up with the

tripod’s three, tool-free mounting bolts.

scope way off balance — in addition to

straining the altitude motor, accidentally

unlocking the altitude lock on the

mount might result in disaster if the

front end of the tube slammed into the

base. Thus, with the scope reasonably

balanced, targets near the zenith are off

limits. Owners of the Evolution 9.25

should consider adding a counterweight

to the rear of the tube, or purchase