alignment on Polaris

[Pixl]

My thanks to who ever posted instructions for setting your geo arc by sighting Polaris. I forgot where I read it, one of the threads on this message board somewhere, but tried it and worked perfectly in one try.

Jim

 

[skysurfer]

My thanks to who ever posted instructions for setting your geo arc by sighting Polaris. I forgot where I read it, one of the threads on this message board somewhere, but tried it and worked perfectly in one try.

Jim

thanks for the memories. that's how I sighted my first couple dish instalsl way back when. Polaris was just visible over the roofline on one of them and I did the polaris sighting thing before I put the reflector on it.

Nowdays I just use the inclinometer to get the angles in the neighborhood, rotate the dish about the pole until I'm about due south and use the signal meter to look for lock on my due south sat and go from there.

 

[Pixl]

Nowdays I just use the inclinometer to get the angles in the neighborhood, rotate the dish about the pole until I'm about due south and use the signal meter to look for lock on my due south sat and go from there.

My South sat is 85° doesn't seem to be anything on it. Using 87° peak and then move over a little I just never got it right.

 

[caddata]

....setting your geo arc by sighting Polaris..../QUOTE]

Yes, it's the most accurate method of alignment. I purposely built my first polar mount with a piece of 2" Sch.40 pipe for the polar axis so I could look thru it (boresite) for alignment. I didn't trust compass or angle finder readings then.
The only trick is to find Polaris.

If you'll notice on bent shaft dish motors, the axis of the motor bearings are in alignment with Polaris.

 

[Mr Tony]

Damn I thought we were talking about snowmobiles

 

[Pixl]

Damn I thought we were talking about snowmobiles

If it was snowmobiles it would be Yamaha all the way! Not the stuff built in Minnesota. Ha

 

[Mr Tony]

hey now.

 

[B.J.]

I own 2 Arctic Cats myself. My Bearcat is a real work horse. Use it to pull a sled around to collect sap from my maple trees in the spring (this year I didn't get anything, due to global warming I guess). But I wouldn't trade my Bearcat for one of those fancy drag racing models.

But back to Polaris, a couple comments.
I wouldn't call it the most accurate method, unless you had an accurate spotting scope attached, and got some good tables for when Polaris was at what angle.
Polaris isn't exactly at the north pole, it's off by about 3/4ths of a degree. I used to have a telescope on a motorized polar mount (I now have a Dobsonian instead), and I had a little chart I was supposed to use to estimate where to aim to account for the fact that Polaris wasn't really north. I never used the chart, because I didn't do anything that requirred that much accuracy, I just wanted things to stay in view when the motor turned.

So anyway, if you use Polaris exactly, you won't be aligned perfectly with the earth's axis, but you'll be off by 3/4ths of a degree.... but this could be a good thing, because you don't WANT to be aligned perfectly. You actually want to be off by about 0.6 degrees. So you could be very close to perfect using Polaris, if you used it at the right time, ie when Polaris was at the hour angle corresponding to your longitude, but if you do it at the wrong time, you could be off by up to 1.3 degrees. It's been so many years since I've even looked through a telescope, I've long forgotten how to do that, but you can probably find tables at the naval observatory site that would tell you what time to do it, that is if it was worth the effort. I still think using a digital level of some kind on the rotation axis is the most accurate way of getting the right elevation, provided that your mount has a good place for the level to sit on. Although Polaris could get you pretty close to the proper Azimuth.

Anyway, it's great to take your Arctic Cats out into the middle of an ice covered lake late at night, stop and look up at Polaris. I don't think I'll do that any more though. Not since I went though the ice a couple years ago. Went through the ice twice actually. Once on purpose rescuing my dog, who went through, and couldn't get out, and a 2nd time when my snowmobile went through. I was lucky both times in that I was close to shore, but it's no fun either way, particularly having to walk a mile home both times soaked to the chin. Anyway, I'm a bit nervous about driving on lakes anymore when nobody is around to help.
Boy, I did it again.... way off topic again. Sorry. I just don't know when to shut up.

 

[skysurfer]

My South sat is 85° doesn't seem to be anything on it. Using 87° peak and then move over a little I just never got it right.

that's okay. Short of a portable signal meter that locks onto DVB-S2, you are correct that there is nothing on 85 deg W. 87 deg W is close enough if all you have access to is a DVB-S signal meter or receiver.

you can get your elevation in the neighborhood by using 87W and then use your extreme sat to get the polar axis set closely. If you don't like yoru results, you can go back to due south (85W), figure out how many counts 87W is from 85W, and move your dish those few clicks and do a final due-south-sat elevation touch-up iand redo your extreme sat again since the elevation change should have changed where the polar axis needs to be.

 

[Pixl]

Anyway, it's great to take your Arctic Cats out into the middle of an ice covered lake late at night, stop and look up at Polaris.

So I could ride a Polaris out in the middle of a frozen lake at night and look up or down and see Polaris.

Actually I wouldn't go out on the lake at night anymore after my wife and I dropped two sleds thru the ice in 60ft of water. We crawled back to shore, pretty scary. Sheriff dept practiced dived on the sleds a month later and brought them up. I dried them up, got them started, and used them for several years before I gave up the sport. Even still rode frozen lakes, but not at night anymore.

I now like satellites over snowmobiles as a hobby.

 

[Pixl]

you can get your elevation in the neighborhood by using 87W and then use your extreme sat to get the polar axis set closely.

Sky, this is pretty much what I did, and getting it in the neighborhood was about it. Might have been dumb luck that I sighted it at the right time and got it in one try. Polaris worked for me.

 

[B.J.]

So I could ride a Polaris out in the middle of a frozen lake at night and look up or down and see Polaris.

Just don't try aligning your dish on the snowmobile.

Actually I wouldn't go out on the lake at night anymore after my wife and I dropped two sleds thru the ice in 60ft of water. We crawled back to shore, pretty scary. ....

My snowmobile through the ice thing wasn't in deep water. The lake had frozen over in mid December, and I had been across the lake several times, but then we had a freak rainstorm, and a bunch of water came down a stream and messed up the ice near where a stream went in. It then froze over again, and I had forgotten about the rain, and went out on the lake not knowing the ice was only an inch thick near shore. If I had kept going, I would have been OK, but I tried turning back toward shore after I got out about 100', and went through. I was lucky that it was only about 3' deep where I was, but I slipped getting off the sled, and went up to my chin. Had to walk a mile home in 12 deg weather. After warming up, I took my tractor down, went out in the water again, with fishing waders on, and tied a long cable and chain to the thing and pulled it out. It started right up, although it didn't ever go completely under, because the near empty gas tank kept the back afloat, and I had managed to get the skiis part way up on the ice to partially support the front.
When my dog went through, that was over my head, but I broke my way through the ice making a path to get to the dog, then used the ice to pull myself back to shore. I didn't realize that it was as deep as it was, or I may have tried some other way of getting to the dog. The dog used to like to swim, but never went near the water again after that.
Both experiences made me not want to go through the ice again. Every year, several people go through the ice up here, and kill themselves. The wierd thing is that people drive their snowmobiles on the open water on purpose. Last year two guys tried going across almost a mile of open water, taking a shortcut to the other side. One of them made it. The other one wasn't found for a couple weeks.

Anyway, I notice you're from Traverse City Mi. I used to work with a guy from there. He went back there when he retired. He has a cabin on a small lake there. You might be interested in a SSTV image I recorded off HAM radio years ago. It was from a ham radio they had up on the MIR space station taking pictures of the ground it was passing over. I recorded a nice picture of Traverse Bay on one pass.
You can see the solar panels and part of the MIR space station in the picture too.

http://www.megalink.net/~wejones/mir-mich.jpg




I think it was taken in Jan 1999. At least that's the date on the file.

 

[Pixl]

BJ,

Quite an interesting story of your snowmobiling adventure. What part of Maine are you in. I've been to Bar Harbor a few times. Great place!
And thanks for the picture of Traverse City from the Russian space station. Amazing the Ruskies were doing ham radio from up there. I'm putting the pix on my desktop.

Jim

 

[B.J.]

BJ,

Quite an interesting story of your snowmobiling adventure. What part of Maine are you in. I've been to Bar Harbor a few times. Great place!
And thanks for the picture of Traverse City from the Russian space station. Amazing the Ruskies were doing ham radio from up there. I'm putting the pix on my desktop.

Jim

Bar Harbor IS a great place, but we're nearly a 4 hour drive from there, in western Maine, so we seldom get there. I can see the mountains in NH from my house.
Re the "Ruskies" doing the ham radio, although they used it too, there were a lot of Americans who flew on Mir too, and they are the ones who took up the ham radios. If I remember right, I think the SSTV was done on a Kenwood HT that had a mode where it could do SSTV, and they just pointed it out the window and let it run by itself. You'd get maybe three or so pictures per pass. They've had similar capability on the ISS, but I haven't tried much with it. Only thing I ever downloaded from ISS was a slate saying something like hello from the ISS, ie not a live picture. But that was a couple years ago, maybe they have better images now, but it's only rarely in SSTV mode.

 

[Greg Mueller]

The easiest way to find Polaris is by using the "Big Dipper"
Using the two stars in the bowl of the Big Dipper opposite the handle, draw a line between them and extend it out. The first star you come to is Polaris