By Kevin Berwick

I bought a Meade ETX-90EC telescope a number of years ago and have just got round to reviewing it recently. Let me say at this point that I have no undisclosed interest in the vendor or product reviewed here and I purchased the telescope via normal channels. At the time I bought the scope, my principal interests were in observing the (bright) deep sky with my Televue TV101 refractor, although since the publication of Charles Wood's ‘Lunar 100', in Sky and Telescope I have become a very keen observer of the Moon. I live by the sea in the suburbs of Dublin, Ireland and the skies, while bright, are fairly good over the sea.

I really love observing the sky and like many astronomers in cloudy parts of the world, wish I had more clear skies. I bought the ETX90 EC as a portable travel telescope. I have brought the telescope to the Canary Islands and to various rural parts of Ireland. In principle, I suppose I could bring my TV101 on trips, but I have had my 101 a long time now and, for sentimental reasons, wouldn't like to risk damaging it as checked luggage on flights.

Like many observers, I find that I am extremely sensitive to setup time when it comes to actually using equipment. If setup takes even ½ an hour, it could be overcast again here at home so 5-10 minutes is the maximum I will devote to setup .For that reason, all my telescopes are small alt-az mounted, rugged telescopes. Needless to say, if I had an observatory, this would change everything, but I am still working towards the arrival of that happy day.

The ETX-90

The specifications of the ETX90EC are very impressive. The telescope is small, at 38cm x 18cm x 22cm (15in x 7in x 9in) including the mount.. It is also very light at 3.5 kg (7.8 lbs.) with electronic controller and 8 AA batteries. The focal ratio is f/13.8, fairly long nowadays.

At the time I bought the telescope, the Autostar Controller , allowing GOTO operation, and tripod were extra, now they are free. If you don't want the GOTO, you can operate the telescope with an Electronic Controller, a paddle allowing you to move the telescope.

I ordered the telescope and Autostar from Dark Star in Wales for a total of £750, a whopping US$1350. The typical price in the US is c. $600...Don't get me started on the price of telescopes in Europe! The telescope and Autostar arrived in cardboard boxes, well packed in polystyrene.

No carry case is included in the price so I ordered one separately. I bought a tripod for the telescope from a friend who uses his ETX90 as a finder telescope now. The tripod is not the same as that for sale currently, which is much improved from the original.

Out of the box

The metal telescope tube has a very high-tech looking, blue finish, which has stayed looking good with no maintenance apart from the odd wipe with a damp cloth. The tube comes complete with a machined metal cover. The optics were dust free, inside and outside, when I looked first and the corrector has a blue colour indicating that it is anti-reflection coated. The aluminised spot on the corrector looked nice and bright from the front, a good sign, even though it is the back of the spot that does the work. There is a baffle in the system, visible from the front. It is possible to remove the front corrector plate, simply by unscrewing it, however, this is not recommended as it could let dust in and also might cause collimation problems. There is no provision to allow you to collimate the telescope, alignment is permanently set at the factory. The tube assembly has a flip-diagonal mirror, allowing you to steer the image 90 degrees from the optical axis. When the mirror is in place, you can use the telescope visually. You can put a camera along the optical axis, allowing the light to fall on the camera by simply removing the mirror by twisting a wheel on the back of the mount. This is a nice feature, you can view an object in the sky and, with a flick of the mirror, be ready to photograph it. I assume you could put an eyepiece in the telescope in the straight-through configuration, but it wouldn't be that useful since once you viewed anything above 45 degrees, the mount would prevent you from getting your eye to the eyepiece. So in practice, all visual use is done with the mirror in place.

The ETX-90 and accesories in carrybox

The focuser is very small and very difficult to reach when the telescope is pointed above about 45 degrees, since the back of the tube, where the focuser is situated, swings over the mount base with minimal clearance. This is a real weak point of the telescope. Various third party manufacturers make flexible cables which can be attached to the focuser to address this, although a clothes peg seems to be the quick and nasty fix of choice!!

The mount is plastic, with locks for the both the azimuth and altitude axes. These locks are very poor. Tighten them too much, or not enough, and the telescope will not move. You do get used to knowing how much to tighten them though. There are setting circles on each axis. Although I haven't used them they don't look as if they would work very well. The azimuth one in particular seems to be made of paper thin plastic. However, since it is a GOTO telescope, I doubt if many people out there would find it a problem. Maybe Meade should think about removing them. The battery compartment holds 8 AA batteries, there is provision on the telescope for running it from the mains. Interestingly, the Autostar takes power from the telescope, it does not have it's own batteries .There is a minute finder telescope on the ETX90EC, a refractor, complete with cross hairs. I find it next to impossible to use since it is attached very near to the main OTA and very hard to get your eye close without banging you nose on the telescope or straining your neck. It is just about usable to find a couple of alignment stars to initialise the Autostar system. I wouldn't use it for star hopping, unless you want to spend your daytime hours in a neck brace!!

You get a free 26mm Plossl eyepiece with the telescope, giving you a magnification of 48X.

Overall, this is a very nice telescope, but the mount is a bit of a let down. This is not a poor man's Questar. Meade obviously built this machine to a pricepoint. They put the money into the optics and the Autostar and sacrificed the mechanical quality of the mount. To be fair, as an engineering decision, I would say that they did the right thing, improving the mount by making it metal would be expensive, bringing the price of the ETX90EC too close to the cheaper of the Meade SCTs. As I understand, the telescope was built to bring GOTO to the masses and it has certainly succeeded in that. Look at a 15 year old Sky and Telescope to see what this money would get you in the late eighties and you will be amazed at how far technology has come.

In use

The telescope is extremely quick to set up. Two bolts connect the telescope to the tripod. Clip the Autostar into the mount and you are ready to go. I left this telescope set up during the last Mars approach and could carry the lot out, in one hand, to my garden for a quick, after work view. This lightness does mean the telescope can be shaky, it is very easy to kick the mount and throw the system out of alignment. I am sure a home made solution involving a bag of sand and some string could fix this easily.