Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

How do I use a telrad?

This topic has been archived. This means that you cannot reply to this topic.
20 replies to this topic

#1 NG98

NG98

    Lift Off

  • -----
  • topic starter
  • Posts: 5
  • Joined: 28 Apr 2013

Posted 01 February 2014 - 12:43 PM

Hello, I just got a Telrad for my Skywatcher 8 inch Dobsonian telescope and I have some questions.
1) How do I attach the Telrad to my telescope?
2) How do I use it to find deep sky objects. I have charts with bullseye's on all the messier objects but how do I use these bullseye's when observing? Does the Telrad need to be exactly positioned like it is on the chart?
3) Do I need to align the Telrad?

Sorry, there are some probably easy answers but thanks.

#2 patg43

patg43

    Ranger 4

  • *****
  • Posts: 350
  • Joined: 20 Dec 2013

Posted 01 February 2014 - 12:49 PM

Well, lets see, my bracket is double sided taped to the main ota. You line it up like a finder scope. It is a zero magnification bombsight. Use it like a finderscope that you don't have to squinch your eye up on.

#3 gene 4181

gene 4181

    Fly Me to the Moon

  • *****
  • Posts: 5,107
  • Joined: 12 Nov 2013

Posted 01 February 2014 - 12:56 PM

i use black electricians tape to hold base on. two places all around tube. comes of cleanly and no paint removed. yes match your telrad charts and object should be there. and yes you have to align the telrad to scope. three screws on back to move .

#4 rowdy388

rowdy388

    Soyuz

  • *****
  • Posts: 3,932
  • Joined: 09 Apr 2013

Posted 01 February 2014 - 01:03 PM

You will soon love your new Telrad. The learning curve for your new toy is very short....it is an easy and intuitive tool for navigation.

First I wouldn't use the double sided tape to "permanently"
install it until you are absolutely sure about placement.
You can experiment with location by holding it with zip staps or something else less permanent.

It mounts with the plastic reticle window facing towards your eye and the three reticle adjustment screws also facing you with the on-off/ brightness lever on the right side.

Look at Polaris with a high power or reticle eyepiece and center it. Then look through the Telrad, adjusting the brightness to a level where you can see the circles but they are not so bright as to drown out the stars. Just center Polaris in the Telrad and you are aligned!
Easy-Peasy.
Have fun. Regards, Dave Y

#5 Paco_Grande

Paco_Grande

    Surveyor 1

  • *****
  • Posts: 1,594
  • Joined: 14 Jul 2012

Posted 01 February 2014 - 01:16 PM

Google is your friend. :D

http://www.company7....cts/telrad.html

#6 mattyfatz

mattyfatz

    Gemini

  • *****
  • Posts: 3,301
  • Joined: 27 Dec 2006

Posted 01 February 2014 - 02:39 PM

The S&T pocket sky atlas is the best star chart I've used (in print form) at the front is a key, and on that key they show you the Telrad projection. It is the filed of view through the Telrad. Super easy to find anything with the Telrad and the Pocket Sky Atlas.

Here are some downloadable Messier star charts, with the objects pinpointed by Telrad projections

I think the Telrad is one of the greatest inventions for ameture astronomy.

#7 kirscovitch

kirscovitch

    Vostok 1

  • -----
  • Posts: 122
  • Joined: 29 Nov 2013

Posted 01 February 2014 - 02:41 PM

I like the tip about using polaris to align the telrad. Viewing from the backyard I don't have anything a significant distance away to try to align it in the daytime.

#8 csrlice12

csrlice12

    ISS

  • *****
  • Posts: 26,739
  • Joined: 22 May 2012

Posted 01 February 2014 - 03:52 PM

Outside of using it to help find celestial objects, I use mine as a battery longevity tester.....I've consistently forgotten to turn it off...Took almost three years of use and being stored in a shed year round before they went dead.....

#9 Kraus

Kraus

    Apollo

  • -----
  • Posts: 1,145
  • Joined: 10 Mar 2012

Posted 01 February 2014 - 04:24 PM

Post deleted by Moderator

#10 lamplight

lamplight

    Mercury-Atlas

  • *****
  • Posts: 2,935
  • Joined: 18 Sep 2012

Posted 01 February 2014 - 06:59 PM

I like the tip about using polaris to align the telrad. Viewing from the backyard I don't have anything a significant distance away to try to align it in the daytime.


I can only see Polaris a little through trees in winter. I have gotten good at aligning my finders on moving stars. ;)

Myself I can't use the Telrad as a sole finder in light polution, and especially with faint targets..but I have used them to get my scope in the right neighborhood, and then use a magnified right angle finder. Those Telrad circles,( the largest 4° I believe) in S&T's pocket sky atlas is Still useful, even with a magnified finder.

#11 kfiscus

kfiscus

    Baltic Birch Dob Bases

  • *****
  • Vendors
  • Posts: 7,095
  • Joined: 09 Jul 2012

Posted 01 February 2014 - 08:21 PM

Many people try their Telrads in a few spots before permanently attaching them. You can use some jumbo zip ties, duct tape, magnets, etc.

The Telrad has 3 small alignment bolts on the back. Once you're aligned, the Telrad keeps alignment very well.

#12 FoggyEyes

FoggyEyes

    Ranger 4

  • -----
  • Posts: 342
  • Joined: 01 Jun 2013

Posted 01 February 2014 - 08:43 PM

Outside of using it to help find celestial objects, I use mine as a battery longevity tester.....I've consistently forgotten to turn it off...Took almost three years of use and being stored in a shed year round before they went dead.....

Oh good. I'm not the only one who forgets to turn my Telrad off.

I use mine so much that I forget that I have a finderscope. Last time I was out, I noticed that the finderscope was pretty misaligned (probably had been for months), which explained why I was having trouble lining some things up. Telrad was fine, but couldn't find anything in the finderscope. Use the Telrad so much, I didn't even care that the finderscope was way out of alignment.

#13 gene 4181

gene 4181

    Fly Me to the Moon

  • *****
  • Posts: 5,107
  • Joined: 12 Nov 2013

Posted 01 February 2014 - 11:01 PM

i would suggest you get the book messier marathon by harvard pennington. it shows you how to use the geometric method of starhopping. i used it when i first started, i've given the book away several times to new people starting out and taught people the method. i have to order another copy for myself. then a pocket atlas and telrad really make sense.

#14 choran

choran

    Gemini

  • *****
  • Posts: 3,130
  • Joined: 28 Dec 2012

Posted 01 February 2014 - 11:12 PM

Re: attachment--you can of course use the tape, or any of the other methods mentioned here, but I think the base also has mounting holes should you decide to screw it to your OTA. That's how mine in mounted. A neat thing about the tetrad is that the circles are 1/2, 2, and 4 degrees so can be correlated with star charts. Also, there is an after-market device you can buy to make the tetrad blink rather than stay on constantly. In fact, I just ordered one. Requires opening the unit and doing a bit of wiring, but doesn't sound too hard.

#15 bluesteel

bluesteel

    Vanguard

  • -----
  • Posts: 2,159
  • Joined: 24 Mar 2013

Posted 01 February 2014 - 11:40 PM

For aligning your telrad with what the scope is seeing, there is no better object in the night sky than a full moon. Large, and easy to distinguish from other objects.
I learned this the hard way when my red dot sight decided to go completely out of whack during transport, and after an hour of trying to figure out where on earth it was pointing, got the brilliant idea to look at the biggest object in the sky then go from there. Also helps if you have a not so great eyepiece so you can see where the moon is due to the light "bleeding" from the edge of your eyepiece.

#16 Astro_Brucitor

Astro_Brucitor

    Vostok 1

  • -----
  • Posts: 137
  • Joined: 19 Aug 2013

Posted 03 February 2014 - 10:22 AM

Hello, I just got a Telrad for my Skywatcher 8 inch Dobsonian telescope and I have some questions.
1) How do I attach the Telrad to my telescope?

I want to second everyone here, you can use pretty much anything, I used black electrical tape to attach mine. It works pretty well and haven't had any issues with it.

2) How do I use it to find deep sky objects. I have charts with bullseye's on all the messier objects but how do I use these bullseye's when observing? Does the Telrad need to be exactly positioned like it is on the chart?

I haven't seen any charts but after your Telrad is aligned with your telescope just move the inner most circle of the Telrad over any object in the night sky and it should be in your eyepiece.
3) Do I need to align the Telrad?

Yep, it's pretty easy. I aligned mine on a street light a few hundred yards away. There are 3 little knobs on the back of the Telrad so just play with those until the inner most circle is positioned on whats in the middle of your eyepiece.

Sorry, there are some probably easy answers but thanks.

#17 Kraus

Kraus

    Apollo

  • -----
  • Posts: 1,145
  • Joined: 10 Mar 2012

Posted 03 February 2014 - 12:43 PM

Post Deleted by Moderator

#18 Philler

Philler

    Surveyor 1

  • *****
  • Posts: 1,555
  • Joined: 15 Jul 2013

Posted 03 February 2014 - 10:52 PM

Some very good advise written here on using a very helpful devise: the Telrad.
If you received it new, I think it came with some instructions, a plastic base and self adhesive tape. But to make sure it is really secure use screws, washers and nuts to complete the attachment along with taping it where you need it on your scope tube.
When I first started using a telescope, I would just sight down the scope tube and then hope the FOV I wanted would be in the finder scope. But the Telrad made it so much easier and faster. The Telrad is much easier to align that a finder scope with the three screws in the front of it, so that you are actually internally aligning it. There are plenty of stars to use to align your Telrad , finder, and main scope together. But if you can, Polaris is the best star since it won't move while you are aligning everything. And BTW, you can detach your Telrad when you are finished observing and it should keep its alignment for next time.

About a week ago, I went to my DSS and set up, and my Telrad was working ok, but just after dark, it quit on me; no more illumated reticle--and I didn't have an extra set of AAs. I thought I had just replaced the two AAs. Sometimes, the cold will just make some things like Telrads and Red LED lights act up or just die. With the Regal LED I just smack it a couple of times and it works ok, but that didn't work with the Telrad.
What I did was just to look through the Telrad lens and use "dead reckoning" to estimate where the red bulls eye should be. This actually worked fairly well and I was still able to find and observe the objects I need to. From now on I'll make sure it has fresh batteries in it and everything else and I have spare batteries,(they are actually cells, not batteries.)

I don't know if this has been mentioned, but you can buy an extention for the Telrad to raise its height for easier viewing.
Also, the Telrad, by itself is very vulnerable to dew. There are different devises to prevent dewing available. I have always used kind of a hood that I lined with black felt that I secured over the front of it that acts as a dew shield, usually works pretty well. I also have a dew shield that I made out of PVC tube that I secured over the front lens of my 8x50 finder scope similar to the idea of dew shields used on refractors. And using this, I have never had the finder objective dew up.

The more you use your Telrad, you will never want to leave home to observe without it.

#19 gene 4181

gene 4181

    Fly Me to the Moon

  • *****
  • Posts: 5,107
  • Joined: 12 Nov 2013

Posted 03 February 2014 - 11:17 PM

i 've even hung a cotton rag over it. keeps the dew away.

#20 Philler

Philler

    Surveyor 1

  • *****
  • Posts: 1,555
  • Joined: 15 Jul 2013

Posted 04 February 2014 - 12:11 AM

i 've even hung a cotton rag over it. keeps the dew away.


I keep a white cotton sock available for the same reason, when all else fails to keep dew off.

#21 ensign

ensign

    Apollo

  • -----
  • Posts: 1,218
  • Joined: 16 Dec 2008

Posted 04 February 2014 - 12:24 PM

For aligning your telrad with what the scope is seeing, there is no better object in the night sky than a full moon. Large, and easy to distinguish from other objects.


When at an observing site before dark, I just find something like a windmill or a silo a good distance away and use that to align the scope and telrad. Works quite well.


CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics