Why I hate Celestron

08.06.2011 on 00:22 • edited 18.12.2012 on 17:08, rev. 5 • no comments tagged - electronics, hardware, hobby

My father got a telescope as a birthday present some years ago. It didn’t cost very much, had a collimator targeter and a nice tripod with servomotors and a wired control. You just plug the stuff or power it with batteries, take the control and press the arrows there - the stuff moves and allows for a precise corrections etc. Not a serious apparatus, but anyway.

The thing is - it came together with a CD that contained some star database, so you could connect the scope with a laptop, calibrate the scope orientation and then just choose what you want to see. The problem was where to get the cable. I couldn’t even find the lenses for the scope to get a more powerful zoom (the two lenses that came together zoomed like binoculars do, or like my 300mm lenses on a cropped SLR camera). At last I decided to dedicate a day for that matter.


So a quick googling got me to some kind of pinouts for the cable. I was happy as hell - I didn’t know what the hell "HC Serial Pinout" (to the right) was about, but it sure looked like a telephone connector, and I had plenty of those cables. The other end is like an old COM port, or RS232 DB9 for those who, unlike me, studied at some technical universities.

The only minor issue was the absense of these serial connectors on modern notebooks. Who would need that when all you gadgets connect with USB? Fortunately, there are plenty of USB-to-COM conversion cables.

That in mind, happy Shein went straight to the electronic market to buy the damn converter, then paid a visit to a electronic components shop to get the COM port. Even bought some stereo jacks to fix the headphones! Next part was to lose time moving one’s butt to get to the house where my parents live, which is not in town.

To cut the story short: I hauled the stuff to the scope, happily torn an old telephone cable to turn it into a double twisted-pair cable with a telephone jack on one end, soldered the COM port to the other end, installed that magnificient celestial database on my notebook, jacked almost everything as it should and -

The phone jack didn't match the scope. Damn. Moreover, any attempt to connect to the scope the "one wire per contact with a tape" way failed as well. I won't even mention how much time I spend twisting the wires to form that nice cable. Rage! And the ugliest part: I recalled that I had tried once to match that phone connector against the scope. My poor memory.

Anyone who can tell me what that this fracking connector type is called will be greatly welcomed. The "HC Serial" tells me nothing, as far as my googling skills are concerned.