Vixen APZ Mount Review
Alt-az
mounts seem to fall into two main categories – push-pull only, ideal for
visual at moderate powers; or goto/tracking.
I prefer a simple push-pull mount for
visual use, but with slo-mo controls for manual
tracking at high powers. The Porta works like this, but it is only properly
stable at high powers with the lightest scopes (refractors up to ~3”).
Enter the APZ – an alt-az that works like the
Porta, but built more like other push-pull mounts and capable of supporting
medium sized scopes.
I’ve owned several Vixen mounts
– including the GP, SX2, Porta and Mobile Porta. I’ve been very
impressed by all of them, except for the Mobile Porta, so I hoped the APZ might
work well with my AP Stowaway for travel.
The APZ also has some unusual design
features that differentiate it from most alt-az
mounts, as we will see.
At
A Glance
Mount |
Vixen APZ |
Weight |
2.2 Kg
mount + 1.65 Kg conical weight + ~ 3 Kg tripod |
Capacity |
~8 Kg |
Data from Vixen.
What’s
in the Box?
The APZ comes
in the usual thick vixen crate with polystyrene inserts. All you get is the
mount head, counterweight and slo-mo knobs.
Design and Build
If the APZ looks strangely familiar,
that’s because it’s essentially the declination axis for an AP
equatorial mount. Indeed, by buying some accessories you can convert it
into an AP - a really useful feature for saving both storage space and cost
(see the accessories section for details).
Otherwise, the APZ appears similar to
many Giro-type push-pull mounts and works much the same. You can just push it
around the sky, but it has those slo-mo controls on
both axes for fine control as well.
Build quality is typical of
Vixen’s equatorial mounts, which is to say excellent. It may use castings
rather than CNC components, but these are finely fabricated and solid, that
white powder coat very durable (as I know from many years of using my SX2).
Mount Head
The T-pattern APZ mount head looks
like a lot of Giro-type mounts from various makers, but has some unique
features.
The APZ comes with a 1.65 Kg counterweight,
screwed into the coarse thread for the AP counterweight bar. The weight is
conical, fits flush and makes storage and set up unusually easy, as well as
looking compact and neat. The weight appears integral, but it is not - it can
be unscrewed for really light loads, or you could thread in a short bar and
standard Vixen weight to balance heavier ones. For scopes up to about 5 Kg
(e.g. a 4” refractor + accs), it’s ideal
as it is.
As you would expect, the APZ has a
built-in Vixen-fit dovetail with both main and safety set screws.
The axes run in ball bearings and so move
with a very fluid action, without the stiction you get with so many. Like the
Porta’s, the slo-mo knobs push on to brass
axles with flats, but are made from a more durable plastic than the flimsy ones
on the Porta and its derivatives.
Tripod
The APZ ships without a tripod, so
you can choose from a range of Vixen ones. It is probably intended for use with
the medium-duty APP-TL130 tripod you see in the photos here and that weighs
about 3 Kg. You could also use the ubiquitous, but heavier, HAL-130. Another
option would be any Berlebach wooden tripod, for which they make a Vixen
adapter.
In some of the photos here, I’m
using the heavy-duty Vixen ASG-CB90 carbon fibre tripod – light at 3.5 Kg
and intended for the larger AXJ mount, so very solid. The ASG-CB90 is very simple
to use too, with just one set of leg extensions locked by big twist-lock clamps
(super convenient in the dark with gloved or cold hands). However, the ASG-CB90
is quite short and so wouldn’t be ideal for longer OTAs where the
eyepiece would be too low with the scope set near the zenith.
In all cases, you have to remove the tripod’s
post for the AP equatorial/SX mount before fitting the APZ head. The post just
screws into the bottom of the centre post for storage – another
thoughtful design feature.
The mount head then slots into a
circular dovetail recess on top of the tripod, so fitting is quick and easy,
even in the dark.
Finally, you just twist the
tripod’s centre pole to tighten the thread into the mount head –
the thread is much coarser and so more fool-proof than a ¼-20” or
3.8” photo tripod thread.
APP-TL130 and ASG-CB90 tripods.
On all Vixen tripods, first remove
and stow the azimuth adjuster post for equatorial mounts.
Tripod is secured by twisting the
centre post.
Accessories
Various accessories from Vixen are
available for the basic APZ:
· A stylish semi-rigid case with lots
of pockets and pouches that’s a snug fit for either the APZ or AP, see
below
· Various tripods, see above
· Motor drives to make the APZ a driven
alt-az, <possibly> with app-based GOTO
using the new WiFi adapter dongle
However, the accessories don’t
stop there! The AP range is modular and you can create various other mounts
from an APZ. This gets complicated, so sit up and pay attention (or just skip
this section)!
To convert the APZ into an equatorial
AP mount, you have the following options:
1) Retain the manual slo-mo
controls from the APZ (see below)
2) A single RA drive motor for tracking
using the Star Book One hand controller, retaining manual slo-mo
for declination
3) Motors for both axes, controlled
with:
a. Star Book One hand controller for
manual-slewing only on both axes
b. New WiFi
wireless module and an app on your phone for full goto
(this effectively replaces the old Star Book 10 goto
controller)
The APZ->AP conversion parts are
as follows:
· Polar Axis unit – the essential
component for the RA axis
· Counterweight bar and weight(s) for
all but the smallest OTAs
· RA motor module set for simple
tracking, which includes the basic StarBook One
controller
· A declination motor to make a fully
motorised mount
· A new WiFi adapter
dongle that allows app-based GOTO
· A polar finder
Note: If you go for either motor
option, the battery holder and wiring are internal, so this end up as a very
neat (if expensive) upgrade. Alternatively, you can power it from an external
phone charger battery (the RA motor has a micro-USB 2.0 port).
(Further sets of parts replace the
declination unit to create a lightweight driven platform for larger camera
setups - functionally like a heavier duty Polarie -
but by then there’s not much APZ left in the mix and it’s a whole
other article!)
APZ plus the conversion kit to a
manually driven AP equatorial.
Manual AP mount built from APZ with
conversion kit (fully reversible!) with an AP Stowaway.
In
Use – Daytime
The APZ is an
astronomy mount, but you could certainly use it as a very stable scope-mount
for birding or nature viewing.
In
Use – Photography
I used the
APZ as a platform for my AP Stowaway when imaging a recent occultation of Mars
by the Moon: with low vibes, zero slop and backlash, it proved ideal for a
situation where long exposures aren’t required.
In
Use – The Night Sky
For loads of
~~5-7 Kg, the APZ proves truly excellent.
On the ASG-CB90 tripod, the APZ is
essentially vibe-free with lighter refractors in the ~100mm class, even at very
high magnification. I have now used it with the Stowaway, an FC-100DC and an
FSQ-85, all of which would tax a Porta except at low powers. But with the APZ,
even drumming on the focuser induces only the smallest and briefest vibes that
damp after a second or so. This means it’s easy to get critical focus.
Pushing the scope around works very well: there is none of
the stiction, backlash and droop you get with most photo heads. It just goes
where you push it and stays there. If you have an unbalanced scope (heavy
eyepiece, camera etc), you can alter the tension with an Allen key. This is
progressive and you can get just the right level to hold the scope but still
push it around.
The slo-mo controls are similarly
good: precise and accurate, with no slop or backlash, allowing for perfect fine
control even at 200x and more (I used it extensively for viewing Mars around
the 2022 opposition).
Viewing Mars
at opposition with the APZ and an FSQ-85.
Summary
I’m hugely impressed with the
APZ and can’t find anything to criticise. It’s like a Porta, but
much better. For small to medium scopes, performance is flawless, with none of
the nasty droop, vagueness, vibes and backlash that plague many alt-az mounts at high powers.
I like the ability to use a range of
tripods, depending on your needs. Sharing tripods with other Vixens is space
and cost saving too (I use the ASG-CB90 for my SX2 mount as well). Fitting it
on a tripod is rapid and fool-proof, thanks to thoughtful design.
The flexibility to convert it to an equatorial
AP mount is a useful feature, as are the various options for counterweights.
The APZ is quite expensive, but you
do get what you pay for here.
The Vixen APZ is a superb piece of
kit that delivers a very stable and low-vibe platform for medium scopes, with slo-mo controls fine and precise enough for high powers. It
gets my highest recommendation.
APZ is perfect with the Stowaway.