Takahashi Teegul Sky Patrol II
German equatorial mount

The Teegul Sky Patrol II is one of the smallest currently available equatorial mounts on the market today. Despite its reduced dimensions, the advised load capacity specified by the manufacturer is in practice effective, this capacity allows the use of telescopes and accessories up to 3 kg both at visual use and small focal lenght astrophotography, turning it ideal to be used with small refractors, up to 80-90mm, and catadioptrics up to 100mm of aperture.

Takahashi Teegul Sky Patrol II
Takahashi Teegul Sky Patrol II

Similary of what happens with telescopes, which use is generally inversely proportional to its aperture, also this rule may apply to mounts , resulting in a greater use in relation to other heavier and bigger mounts. In the reality, on this aspect does not remain big excuses for not the use this mount.

One of the main reasons, if not the only one, to acquire an mount of this size is without a doubt its great portability. Its small size is truily notable, only being possible to appreciate such fact seeing one "live". But despite its miniature size, it delivers the same quality of construction and materials present on all the other bigger and heavier Takahashi mounts, having among others features, the characteristic signature color of Takahashi "industrial" rugged green-rasp as well all quality of finishing and materials.

Specifications

Reference: TG-SP II

The Teegul Sky Patrol II is an German equatorial mount type with a quartz controlled step motor on the right ascension axle. The declination axle can be rotated manually.

  • Motor: 6V quartz controlled step motor with 170mA consumption featuring two speeds: sidereal and 2x sidereal. The two bronze gear wheels are in with 50 teeth each having a diameter of 40mm (1,5"). The gear wheels have a revolution of 17 minutes and 20 seconds at sidereal speed. The worm period is about 8 minutes.
  • Maximum measures (assembled): 45cm x 20cm x 10cm. counterweigth shaft (Ø12mmx130mm).
  • Total weight (with a 650g counterweight (Ø60mmx30mm) ): 2.4 kg
  • Temperature of operation:-5° [23°F]~ +30° [86°F]
  • Included acessories : 4 A 1.5V batteries pack, an hand controller with two push buttons to 2x sideral speed e and to stop the motor and North/South swith wich invertes rotation to the correspondent hemisfer and also metric 2mm allen tool for mounting.
  • Angle of operation: 360 ° em R.A and DEC (using included low-profile knob)

Description

Takahashi Teegul Sky Patrol II
Takahashi Teegul Sky Patrol II
4 views of the assembled mount showing the balanced and apellative design.

On a first analysis this mount evidences an excellent and well-thought design combined with a solid construction, almost of industrial specification, or on other words, with the quality and robustness to support intensive work in less propicious conditions. I consider this aspect a prerequisite for equipment that has that to support the extreme conditions like moistness, extreme temperatures and wind that that many times occur on (the generally good) astronomical sessions on the open field.

The mount has three blocks and a plate made of hard-aluminum. The block that lodges the R.A motor wich executes the movement of right ascension, can be also be moved manually using a knob. In this block are mounted the twin gears wheels that transmit the movemen to the worm-gear (internal) . This engine block was smartly placed on a position that also allows it to serve as a counterweight.

The declination block can only can be turned manually using a knob. Both the blocks are fixed in a plate that that function as polar axle being both screwed the lode of the counterbalances. The knobs are the only plastic parts s on this mount but however they are deceptive at the first sight.

Each one of these blocks is joined by only two interior screws that can inserted using a 2mm Allen key, pressing two pernes that enter in their respective sockets.
This way of connecting the blocks cannot be considered very safe however, as long as you don't exaggerate too much on the load weight . It is however an important detail to have in consideration because it can cause the loss of ortogonality, or on another words, the loss of the perfect alignment between the two axis that will cause particularly nefast effects on a posterior polar alignment.

In practice, the checking of the good alignment between the two blocks is mandatory , especially if the purpose is to do
long exposure astrophotography, specially using bigger loads than the specified by the manufacturer.

Takahashi Teegul Sky Patrol II
Takahashi Teegul Sky Patrol II
Assembling and disassembling the Teegul are a question of minutes, being only necessary to screw 4 threads. The 4 bigger parts allow to
store the all mount on a case with the maximum dimension of 20 cm(clique na imagem)

Mounts Base

It is usual the German equatorial mounts to have a base that can be adjusted on altitude and azimuth in order to align it with the celestial pole. The Teegul simply does not have this base. The mount has to be obligatorily fixed on support with the site's inclination (latitude) or in preference, on an equatorial platform that allows these adjustments.
The mount is fixed using a 1/4"screw thread wich is the standard 35mm camera thread, being therefore possible to use any photographic tripod. I don't consider this screw size a safe or durable way of fixing this kind of weight but has not shown any problems until now with exception when overloaded.

The reason of the choice of such a small thread was certainly the compatibility with small photographic tripods , but I do think that the 3/8" thread size, used on the medium / heavy photographic tripods would have been more adequated for an mount of this weight. Without a doubt that this thread size would inspire more confidence and reliability over all, especially when total weight could easily go up to 7 or 8 kg, because you have to always have in account the weight of the mount, and weight of the instruments and accessories such as telescopes, cameras and objetives and the rest of the remaining accessories.

40° Adaptor (TG-SV)
40° Adaptor (TG-SV)
This adapter (optional) can be mounted on any photographic
tripod and provides an inclination of 40° necessary it Teegul to be able to work in equatorial mode (obviously in places with the latitude close to this value). One another optional adapter also exists available (Tg-SH) that it allows one to adjust
for the inclination of choice.

Improvised equatorial base
Improvised equatorial base
To be able to get a rigorous polar alignment, that is obligatorily for astrophotography it is necessary an adjustable platform in altitude and azimuth.
The equatorial head on the photo above was adapted of a Meade tripod for the ETX90, having been made a custom aluminum plate to connect the Teegul.
It is not the perfect solution but however it has served well

Improvised Equatorial base
Improvised Equatorial base
Despite the solid aspect, the fact to have only one point of
attachment forces use a pad to increase the friction between the mount and the plate to prevent slipping.
It´s really a pitty the thread being so small it would surely prevent this from happening

Hand controller

The hand contrller has a espartan but however functional appearance. It has the characteristic and typical aspect of the Takahashi's equipment, wich by the way, I really do appreciate . It could not be simpler. A button to stop the engine (blue) and other to speed up the R.A motoro to the double of the speed (red) and one other to switch the motor that has one led red that blinks if the batteries are weak.

In contrast to the great majority of the hand controllers, the purpose of these buttons is not for centering the targets to observe, but to do corrections to the tracking speed when executing a guided long exposure photograph or even to make small adjustments at big magnifications.

On a mount rigorously lined up by polar axis it would only be necessary to correct the inherent variations to the engines and gears or some flexure (and periodic error,lack of balancing and atmospheric refraction), witch all can cause delays or advancings in relation to the sidereal speed, being only necessary to stop the engine when it is gone too fast, or then to speed up when it is too slow, there the necessity of only possessing these two buttons.

This would be enough if the polar alignment was always perfect. Normally a polar alignment using the method of the "star-drift" can be executed in about half hour or more than one hour, considering the focal lenght and the time of exposure intended to photograph. For who it does not have the luck to possess a observatory with the mount fixed permanently, the rigourous polar alignment procedure is always unavoiable independently of the size of the mount.

The hand controller
The hand controller

The lack of any remote electric declination adjustment can only be considered inconvenient by having to be substituted by a good polar alignment. With rigorous a polar alignment will not be necessary to correct the declination except to compensate the atmospheric refraction. But an eventual declination correction is always possible to execute manually by using the declination knob, that has enough precision and smoothness to make corrections in declination with just some seconds of arc.

Motor and gears

The equatorial mounts are conceptualy simple to design and to manufacture, being its bigger problem the required machining precision for the gears that are responsible for best affordable accuracy, to track the rotation movement of our own Planet.

On the Teegul's case, the motor used is a step-by-step type with resolution of 24 steps and a desmultiplication ratio of 1:500. This results on a rotation period of gear wheel with 40mm of diameter and 50 teeth in each 17 minutes and half. This gear in turn is engaged to another identical gear wheel that will transmit movement to internal worm-gear and allows the use of the manual knob without the need of desengaging.

The gears
The gears

I cannot guarantee that it has an worm gear inside the R.A base because I didn't have the courage yet to
disassemble this block (it was not yet necessary). But you can guess it, because it shows a clear period of revolution as the below periodic error test demonstrates.

The setup
The setup

Using an webcam and the IRIS "Autoguiding" option it is possible to generate a ASCII file where corrections (in pixels) to DEC/RA are written along with the time. A Tak FC60 f/8 and a Powermate 2.5x was used resulting on a sampling of 1 pixel per arcsec.

Gamma Andromedae
Gamma Andromedae

For convenience reasons (a small and low sensitive CCD) a bright double star was used to calculate the image scale in pixel/arcsec, being chosen one, the nice double Gamma Andromedae (Almach) having later used the separation (9,57") published on the" Tycho Double Star Catalogue # (TDSC) (Fabricius+ 2002). The test star was alpha Ceti (Menkar) with 4° declination to minimize some probable bad alignment, having this star transited the meridian during the test.

Periodic error
Periodic error
The graph evidences a periodic error of +-15 arcseconds with some peaks during the 26 minutes duration of this test.
The curve is fairly adjusted to a sinudoisal curve denoting previsible and non-erratic behavior.
It is also obvious an ~8.5 minutes worm gear period.
Graph was normalized by subtracting a trend line probably caused by motor tracking errors and/or some lack of balancing or not so perfect polar alignment.

Periodic error
Periodic error
In this graph based on a section of the previous graph a periodic error of +-4 arcsecs during a 1 minute period.
The spiky aspect is due mainly to atmospheric turbulence.

The Teegul dismantled
The Teegul dismantled
Notice the necessary tools to disassemble the engine, gears and
command, only one 2mm allen tool and a small screw driver. The number of parts is small. There are "Legos" quite more complicated to assemble...

Observing a star at 250x is possible to notice the instant engine response when speeding up to sidereal speed was even when loaded with 4 or 5 kg.

However, the engine presents a delay when the R.A wheel is turned manually. Having an delays of about a dozen of seconds to be compensated, something to have in account when is intended to center a star for the guidance.

To who is aware of mounts typical periodic errors values, can be wondered why so small gears and with so few teeth still achieve quite respectable periodic errors values. In a word: precision.

The diameter of the gear wheels and its tooth number alone can be only be considered as advantage on gear wheels constructed with same precision degree . Even the small and 50 teeth Teegul's wheels , have a very high grade specifications, hence its performance. That also also explains the pure mechanics performance of the bigger mounts as it is the case of the one EM-10, EM-200 and bigger models (bigger wheels with more teeth and same quality).

It is quite notable the performances of these mounts without any assist of electronic correction circuits such as PEC (Periodic Error Correction), even so, its use on mounts with gears with these standards of quality turns them absolutely perfect performers.

But returning to the Teegul, this mount does not possess any PEC circuit and even possibility of being corrected by a CCD autoguiding. It is a simple, basic, mechanical mount , but again, with quality. Quality that allows with some perseverance and devotion to be able to execute observations and tasks for which was not really designed for.

Energy

Thanks to the little electronics and the small step motor, its energy requirements are also small, resulting on a great autonomy. With only four A alkaline batteries of 1.5V will endure more than 20 hours of continuous use according to manufacturer, but however it is easy to construct a small cable to use a 7amph gel-battery instead, that wiil virtually provides an autonomy of months on regular use, with the additional advantage of being less immune to the low temperatures when compared to the normal dry batteries, being able also to use simultaneously dew-removers and other accessories. The controller's LED monitor the battery's load, blinking in case of low charge.

Transport and case

The portability and autonomy are the most attractive factors , being possible to place the mount, telescope, eyepieces several accessories on a photograph bag such as the photo below shows.

Transport bag
Transport bag
This bag was designed to carry and protect photographic
gear, therefore more than suitable to the sensible optics and mechanical parts . This bag is a LowePro Photo-Trekker AW.
This model can be is also a backpack and will carry a tripod if needed. Having also the advantage of be allowed as hand luggage on most airplanes.

Applications

Visual

It is the most obvious application and by far the most used. The maximum load weight of 2,5 kg can be exceeded on visual observations as long it is compensated with counter-weights. I have knowledge of users to mount telescopes with 3 and 4 kgs for visual observations. The small engine has enough force to carry the load without apparently making any effort. The only problems that will probably appear are is enough tack on the base of the mount or loss of axis ortogonality due to the reasons already above on the "Description" section.

"light" setup
"light" setup
A good tripod is enough for many of the tasks, as solar observations, eclipses and planets.

On visual observations I consider generally enough an medium size photography tripod, such as the Gitzo G1224 with the inclined base 40°, inclination that is enough close to the latitude of my usual sites(39°30 ' N). I even find it adequate up to 200x magnifications.
With moderate or strong wind, or if it is used on public place I prefer to use the excellent wooden tripod Berlebach for enhanced stability and security.

Afocal Astrophotography

One of my more frequent uses is the solar afocal photography. This type of photograph is typically very fast exposures around 1/500s or faster and isn't obligatory to be properly aligned , being enough to point the mount in the general North direction and not generally necessary the use of the R.A. motor, except on the case of if intending that mount follows the Sun on cloudy days. Also in this type observation a good photography tripod will be enough.

Lunar Eclipse
Lunar Eclipse
8 second exposure
(clique na imagem)

On lunar and deep sky photography, a more robust tripod will be advised along with a more precise polar alignment, due the higher focal lenght and longer exposures, as well by the use of adapters (more weight) to hold more conveniently the camera to the eyepiece.

The high requirements of afocal photography are equal or bigger to those on the photography on prime focus, the only inconvenience is same of generally not being possible to remove the compact digital objetives, but however already starting to appear digital SLR at more accessible prices well , that allow photography on prime focus, much like the traditional SLR cameras.

Piggyback Astrophotography

This is in practice the most adequate way to make photography with this mount.
Generally the term piggyback is understanded as the camera being on the top of telescope, but in the case of the Teegul the camera is piggybacked on the mount instead. Being such a small mount, it is desirable that the camera and objetive act like counterweights to reduce the overall apparatus weight , but however this configuration has the inconvenience not to allow any eventual correction on declination axis.

The usual configuration consists of putting a guide telescope to follow a star at high magnification (250x), making corrections along the exposures. The limit is only the patience of the photographer or when starting not to feel the feet's fingers. Personally rarely exceeds 10 minutes.

The equipment normally used is :

Piggyback
Piggyback
This is usual configuration for 300mm astrophotoghy.
It is in practice (my) maximum limit for the long exposure astrophotography with the Teegul.

This will be perhaps the form desconfortable to do astrophotography.
To visually follow a star at more than 200x during 5, 10, 20 minutes many times in the way in the midlle of nowhere, with cold, moistness and wind during all this time cannot be considered properly a comfortable activity .

But, however is extremely rewarding when one or another photo results well , and because they are very personal photos, without practically any assisting excepting the knowledge and devotion of its author that is only helped with two buttons command that stop or acelerates a small motor engine on the attempt to follow the best he can the rotation of our planet . These images regardless the little deepness, defocused or under exposed that they are, have a very personal value for effort taken, than technical know-how, that is generally losed among the batteries, computers, autoguiders and CCDs. Is like to drink wine stepped with our own feet - has another flavor... even if it is bad one...

La Palma
La Palma
50mm f/4 5 minutes on Fuji Superia 1600
(clique na imagem)

Messier 35 at Gemini
Messier 35 at Gemini
5 minutes exposure with 300mm objective at f/4.5.
(clique na imagem)

Similary whith other mounts, the engine behavior when it goes up or when it goes down is different, especially when the tube and camera are on extreme positions, being in many occasions impossible to balance it. Where me it seems more certain is when the target to photograph is in + - 15 degrees around the local meridian .

Obviously that in the current times with a (somewhat bigger) amount of money is possible to go around all these inconveniences, by buying equipment and observatorys that allows to make imaging on a more comfortably way, and make images that are simply impossible of executing with such a simple and manual mount.

In truth, to take good photographs using a Teegul is by far more laborious and difficult...

Astrophotography with medium and long focal lenght

The webcam planetary photography can be executed with relative comfort, with focal lengths longer than 3 meters, being enough the mount to be lined up even with a compass. The manual commands are enough precise with these focal lenghts. Although it is advised the use of a robust tripod for the acquisition of images at this focal length is possible to get images easily using a good photographic tripod roughly lined up.

webcam
webcam
Planetary images with webcam and an ETX90 at f/35 (3,15 meters)

Mars, Saturn and Jupiter Mars, Saturn and Jupiter
Mars, Saturn and Jupiter
Mars, Saturn and Jupiter
Meade ETX90 + Powermate 2.5x (f/35)

Use

Using the Teegul

This mount is absolutely basic.

It does not have "go-to ", nor digital circles , nor polar finder truily functional (see below) and not even an adjustable equatorial base, and for such requires some knowledge of the sky to effectively be able to use it.

This lack of "modern" attributes however will not stop a truily interested owner to use it without great difficulties and even make some photographs. Even whom does not know how to read Japanese which is the only manual's language.

Having been this my first equatorial mount, I found at the beginning its handling bit strange, especially while observing objects at low East and West, but nothing that some use did not attenuate, this by releasing both axis and to be able to easily point the telescope as easy as with an altazimutal mount.
In comparison with bigger mounts, I cannot say that this one has soft movements like "butter", but more of the type "tight and fit", giving small jumps when overloaded , like a vibration when manually and brusquely adjusted. This somewhat brusque behavior must to a large extent thanks to its size and little mass.

The screws to engage the axis are quite small, so sometimes this procedures is a bit desparing, because sometimes the axis screw will not be suficiently pressed. It is necessary to acquire "the magical" touch, not too much pressed nor insufficiently pressed.

An annoying detail is about with the position of the on the R.A axis screw that does not allow to twirl the mount 360° on this axis, for the reason that gears's protection plate will struck the manipul. This will require to loosen the mount from his base to twirl it in order to prevent this from happening.

I also found necessary to add a ring to increase in the telescope´s distance from the base of the mount. This costum-made aluminum ring in (see photo above "piggyback"), will prevent that the telescope tube from eventually hit the tripod legs if it loses, with the additional benefit of allowing and facilitating observations at the zenith.

After 6 months of use...

More than the first impressions on a new equipment, I do consider more relevant how the equipment supported the use during one farely long period of use.

In the reality, with just 6 months of use, this mount not being of "hut" use, already supported (similar to its owner) few hundreds of hours of effective use in the most diverse conditions, from negative temperatures the very high temperatures, to been completely wet countless times, long sessions of 10 ten hour duration, rain, wind, solar storms solar and etc...

With (mine) quality equipment, I am generally demanding and hard user, but not neglected, but even with its correct use, is still an intensive use and is natural some times natural scratchs to happen beside the normal use wear.

My Teegul exhibits some of these marks, that can be considered of "war scars" , although that to intervene with its normal functioning, some would be enough more considerate owners to run to buy one can of ink to retouch them (curiosity: the Takahashi sells small cans with the original colors for retouchings).

Takahashi Teegul Sky Patrol II
Takahashi Teegul Sky Patrol II
On the palm of a hand

But however mechanically it is almost as new. Mechanical slack do not exist (except the initial slack of the gears after being meshed, something the engine always had), nor rust, nor parts, nor seem to be in ways to happen such damage and defects - I consider this truly admirable fact, especially knowing the abuses that suffered.Electrically it is also as new. The only time I had necessity of disassembling it was to take the photos above...

The only visible wear marks are the ink pulled out on the base where the mount is fixed, that can be seen on the photo mosaic above and that it was caused by having slid due to tack caused by extreme weight. The rest is is spotless and it never failed at any aspect.

It can be a somewhat exaggerated afirmation , but its notable reliability makes it a true "combat" mount, that seems to have been made to endure the most adverse conditions and intensive and abusive if necessary use.

Resuming

The most important aspect of an mount with some pretensions to do astrophotography is without a doubt its tracking precision. An mount that doesn´t tracks well for its load specifications, simply failed on its more important and main function, this independently of the price. As on everything else, the necessities dictate the price to pay for the functions and intended loads.

The Teegul was conceived for visual use with (very) small telescopes and to photograph short/medium exposures with 100-200 mm photographic objectives , and can be considered almost perfect for these specifications.

In the reality the mount's performance can be considered excellent having in account of that he is possible to duplicate the the specified load and focal length and to obtain quite reasonable results. What more can ask to a manufacturer? Maybe to manufacture them cheaper but with the same quality...

Cannot be asked expected for a bicycle to speed at 300 km/h - not even to the best and more sophisticated model, therefore cannot be expected the Teegul to make photos with the depth that generally populate websites and astronomy's magazines. This assembly isn't surely for deep sky or CCD astrophotographers , or candidates to such, except if have a bit masochistic mind.

Using another equipment (certainly more expensive and surely heaviery) and with less work and difficulties, better results can obtained and with much less frustration.

If using this mount to execute the tasks for which it was designed for, on a light and portable package this mount is one of the best offers possible. For my case in particular (mobile visual observer) that likes to make images time to time, serves almost in the perfection.

The Takahashi brand is synonymous of quality, but also it is synonymous of very expensive, and the Teegul obviously wouldn't be the exception - in both the cases. At about 1000 € (without tripod and polar finder) costs a bit to give for such a basic and small mount, but is this the price of the not only of quality, but of guaranteed quality. This mount as been function 100% since it left the box. Lubrications, tweakings and interminable searches on the Net to solve problems that shouldn't have to exist weren't necessary.

The price however can be considered outrageous, especially if you can acquire an EQ6 with tripod and everything for less money. But after adding the doctor's bills because of hernias caused by carrying for example a EQ6, perhaps isn´t not that cheaper :), for beyond if having the luck to grab one that is acceptable on the "lottery". In the reality the Teegul cannot be compared practically another one of this class, at least at this size and weight . I have knowledge exists the Eq-1 of the Orion, but I never saw or use one so I shouldn't compare.

I do consider obligatory to measure very well the reasons to want an mount of this kind: is the biggest portability at the higher cost. As in everything, it is a commitment between cost, quality and use. Obviously sometimes I would like to have a bigger mount and with more precision, but on the other hand, other occasions I do not - well, but is better to start saving to buy a "bigger sister"...

Gallery of images
Takahashi Teegul Sky Patrol II Takahashi Teegul Sky Patrol II Takahashi Teegul Sky Patrol II Takahashi Teegul Sky Patrol II
Takahashi Teegul Sky Patrol II Takahashi Teegul Sky Patrol II Takahashi Teegul Sky Patrol II Takahashi Teegul Sky Patrol II
Takahashi Teegul Sky Patrol II Takahashi Teegul Sky Patrol II Takahashi Teegul Sky Patrol II Takahashi Teegul Sky Patrol II

Links to other commentaries

Polar Finder

One of the optional accessories is the polar finder, it is a well constructed piece, but it can not be considered practical nor an absolute necessity. On previous photos it is possible to notice the place where the this finder is fixed, that besides leaving markings on the paint, is practically impossible to put on the place in the same position if removed, so it will be disaligned in relation to the mount.

The finder's position doesn't help much either, it's almost impossible to use it with the mount on a tripod or equatorial platform because the legs of the tripod will obstruct the view. I find odd Takahashi to have this accessory knowing that would not be practical to use it (another possibility is I didn't get it...). For the price that cost it could be illuminated as well.

But however if used, it guarantees a precision of 30 arcminutes, that will be enough to visual observing and 50mm photography or less, with short exposures.

Polar finder
Polar finder
This small finder has a 10mm aperture with a 12° field and magnification 3x, the eye relief is small, not being possible
to use eyeglasses. It weighs 115 grams.

But there is a more convenient and precise way to use this polar finder. Having arranged a small aluminum 'L' bar in al, becamed possible to line up the finder its support being used the 6 small points of refining (screws), in a well more confortable position. In practice, I only use this support when I need a more precise alignment for photographs of short duration (10 seconds máx.).

Polar finder
Polar finder
After the mount is rigorously lined up by the method of the drift, this adapter is placed and the finder is more permanently lined with its support

The two eyes have to be used simultaneously to line up with this finder. One to look at the Polaris through the finder and the other to trace one imaginary line between two known constellations, the Ursa Major and Cassiopeia, more precisly between two of its stars.

The constellations are almost in its totality circumpolar at continental Portugal's latitude (37°-40°), therefore always visible all the year, but however a great area of sky at North quadrant as to be cleared.

The finder's reticle is constituted by 3 concentrical circumferences, on which must place Polaris or the Sigma Octantis on the case of the South hemisphere.

Reticle
Reticle
It is enough to place the Polaris over the corresponding circumference, observing the relationship between the constelations.
if it was illuminated would be well easier.
I use a red led lantern to facilitate the reticle's view.



Luís Carreira, April 2004