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Using a Telrad for Locating Alignment Stars

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#26 csrlice12

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Posted 22 January 2014 - 08:27 AM

I reached a watershed moment last night......I had to change my Telrad batteries....both of them. They finally went dead after my memory experiment failed, causing me to frequently forget to turn it off.

#27 Dan Finnerty

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Posted 22 January 2014 - 07:39 PM

I reached a watershed moment last night......I had to change my Telrad batteries....both of them. They finally went dead after my memory experiment failed, causing me to frequently forget to turn it off.


Any guess how many hours of run-time you had? Curious how long these batteries will last.

#28 petrus45

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Posted 22 January 2014 - 10:19 PM

I've inadvertently left the Telrad on for days at a time without draining the batteries.

#29 csrlice12

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Posted 22 January 2014 - 10:23 PM

Its been three years and there have been times its been left on for weeks...

#30 Jon Isaacs

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Posted 23 January 2014 - 08:04 AM

I reached a watershed moment last night......I had to change my Telrad batteries....both of them. They finally went dead after my memory experiment failed, causing me to frequently forget to turn it off.


Any guess how many hours of run-time you had? Curious how long these batteries will last.


It depends on the brightness... I recently measured the current draw of a Telrad. At maximum brightness, it was 12.4ma. At full brightness, 2000 ma-hr Alkaline AA batteries would last about a week.

But no one uses a Telrad at full brightness. A more normal brightness measured 0.4ma and the 2000 ma-hr AA cells would last about 200 days.

Jon

#31 Astro_Brucitor

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Posted 25 January 2014 - 02:12 PM

So I got my Telrad in the mail yesterday and promptly installed it on to my telescope. As mentioned in previous posts it was quite easy. I removed the telrad from the mounting plate and used electrical tape to attach the mount to the telescope then reattached the Telrad to the mounting plate.

Once under the stars using I aligned the scope and the Telrad using a street light about 300 yards away (100'ish meters) and calibrated the Telrad to match what I was seeing in my eyepiece.

Once the Telrad was aligned with the scope (took about 5 minutes) I used the Telrad to find Jupiter and once I did it was inside the eyepiece and it took about 30 seconds.

From there I locked the RA and Dec tabs on the mount and turned the mount on and had no problem finding alignment stars as long as I could see them.

In summary the Telrad was 100% worth the $40 I spent and has made finding alignment stars incredibly easy as long as I can spot them in my light polluted skies. I would definitely recommend this as a must buy for any beginner astronomer/astrophotographer.

Thank you to all the awesome people who gave their input on this much appreciated =o)

#32 George N

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Posted 25 January 2014 - 05:33 PM

One nice thing I like about the Telrad on my 20-inch Dob: I can use it while standing on the ground! That helps a lot with finding alignment stars, especially at dusk with just 1st mag stars visible.

I saw a guy with one of the four Obsession 36ers who had added an extra pole on the eyepiece side of his mirror box. The pole had a 7x50 monocular (or half of an old binocular?) with cross hair eyepiece mounted at the perfect height to use while standing on the ground.






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