Last updated: 12 August 2005
Subject:	ETX 105 - first impressions
Sent:	Thursday, August 11, 2005 14:01:35
From:	Derek Pratt (
Attached is a possible contribution to the 105 page of your excellent site:

I nearly succeeded in following the standard advice given to those new
to astronomy, namely don't buy anything fancy until you have joined a
club, looked at what others have got and listened to their experiences.
What threw me off this eminently sensible course was the chance to buy a
nearly-new ETX 105, with more accessories than even a gadgetophile like
myself could wish for. Electric focuser, deep space imager, lunar
planetary imager, imagemate, dew shields, filter, power supply, more
filters, the list went on and on. Even the number of cables reached well
into double figures, and the simple task of performing an inventory
seemed to stretch endlessly in front of me.

The scope herself was an immediate object of desire, a sleek and
seductive temptress, jet-black with purple highlights, who whirred her
altitude and whizzed her altazimuth at the touch of a soft-feel button.
And the sensuous way the handset glowed all her controls red when
switched on was clearly designed to lure the hapless new owner into
plunging headlong into her hidden mysteries. The manual tried its best
to keep the novice stargazer on track - adjust this, align that, on no
account do b unless you have first done a. But the temptation to just
press things was too great. No matter that the software delivered a
sharp retort - if you really want to see Saturn tonight you've got a
four-hour wait, and if you must observe Jupiter this week you'll need to
demolish half of that bedroom wall. It was worth it just to see her

Eventually the rush of enthusiasm died down sufficiently to investigate
some of the essential features in a more orderly fashion. The focuser
was first, with some tentative prods of the controller being rewarded by
a vague bluish object appearing in the eyepiece that resisted all
attempts to make it more distinct. A fear that the device was falling
down on the job was at least partly assuaged when the realisation dawned
that I was imaging the clear eastern sky, in broad daylight. The finder
had been aimed at a pair of chimney pots down the road, so the need for
mutual alignment was a lesson quickly learned. Eventually, with some
screw-twisting and more button-pushing I was able to determine that the
cracks in my neighbours' pointwork were not such as to cause their
chimney to collapse. Not for a while yet anyway.

Reading the manual a little more attentively at this stage revealed the
need for training, to minimise backlash and improve performance. This
struck an immediate chord of recognition - how many times in my life
have I suffered backlash and performed badly due to lack of training. I
sympathised wholeheartedly, and resolved that my new astronomical
partner would never suffer similar indignities, whatever it took from
me. However the process turned out to be simplicity itself, just a
little game of follow-my-leader with her drives as they sashayed left
and right and up and down, like some stately slow-motion ballet. My
choice of terrestrial target was not of the best - a tall featureless
pole which gave a clear indication of longitude but a somewhat
inconclusive estimate of latitude. However we got there, and at this
early stage in the relationship I fought shy of asking her to do it all
over again because of inattention from the human half.

Calibrating the motors, now that sounded like a manly, technical
operation worthy of a trained engineer like I nearly was many years ago.
Wrong again. Merely some lightening-fast internal calculation of volts,
amps, joules and no doubt the current (sorry) values of pi, e and c to n
decimal places, followed by a quick burst of slewing to check the sums
added up . All over in a blink of an eye - this lady was clearly
impatient for action.

Unfortunately neither of us had control of the weather, which was
resolutely cloudy for several nights in succession. The obvious thing to
do was to read the numerous manuals, instruction sheets and similar
literature and get myself fully acquainted with the idiosyncracies of my
new mistress. So instead I played with the DSI, trying with minimal
success to get a focused, recognisable image on the laptop. However the
lack of a high-speed USB connection meant the software dawdled rather
than ran. Simple solution, buy a USB card. But the card port has broken
pins.... Simple solution, buy a new laptop. But the credit card has
broken its spending limit.... Simple solution, put the DSI back in the
box and play with the model trains until the weather clears.

Eventually the day dawned, or rather darkened, when the clouds dispersed
sufficiently to allow a brief glimpse of the heavens. The process of
setting up was then commenced, with a logistical complexity which must
be recorded to be believed:

	1) Carry accessories case downstairs to the utility room
	2) Open back door, push cat away from same and carry case out into the 	garden
	3) Remove cat from utility room
	4) Carry tripod downstairs, repeat (2) and (3)
	5) Repeat (4), including (2) and (3), for the telescope
	6) Erect tripod and attach telescope, trying not to wonder what
	happens if 	the ETX slides off into the fruit bushes
	7) Commence darkening exercise within lower rear of house
	8) Remove cat from utility room and approach telescope
	9) Return to kitchen to switch off light turned on by son# 1 
	10) Remove cat from utility room
	11) Repeat (9) and (10) until son# = 5

Eventually everything, including the cat, was outside, in the dark and
with the family banished to their bedrooms. The safety torch was turned
on, bringing on slight feelings of guilt about whether I should enjoying
a leisure activity in a red light district. How different she looked in
her natural element - I hardly dared touch. Plucking up courage I
pressed the ignition switch and initiated the start-up sequence. No
Shuttle pilot ever followed the rule book so closely. I was rewarded by
a near-faultless performance on her part, but only mixed results on
mine. One problem was relating the views obtained via finderscope and
OTA. The alignment seemed OK but it was difficult to actually see what
was being pointed at. Still actually looking through the scope was well
worth all the effort. The focuser worked well, once I worked out which
way was in and which out, and had the patience to let it get to where it
was going.

A couple of nights later a second practice session was feasible. This
time I concentrated on just looking, to get a feel for how much is
actually up there. Comparison with a modest pair of binoculars was
instructive - the trade-off between magnification and field of view was
immediately apparent. The finder was still tricky to use effectively,
and I found myself looking with increasing interest at adverts offering
alternatives. For the outcome, I'll leave to Episode 2, if I ever get
round to writing it. And yes, I will pay a visit to my local society.

Derek Pratt
Southport UK

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