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Telrad? - Tick!

Demonperformer

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Demonperformer

Demonperformer

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Due to streetlights drowning out rdfs and never being able to get on with telescopic finders, I have spent most of the last five years aligning my scopes with a wixey. Although tedious, I have become quite proficient at this technique. However, a while back (can't find the original thread, but have a suspicion it was 2013 sometime), after reading a lot of positive reviews and getting some great advice on here, I splashed out on a telrad. With my normal glacial progress, I attached it to my 8SE last week and gave it a test-drive.

My first thought was: I wonder if I will attach it so far off 'true' that I won't be able to get it to line up? [This is the sort of thing at which I am really adept.] A quick look at the base in relation to the scope offered a simple solution. I butted the back of the base legs against the raised bit around the mirror cell. I positioned it so that it is at the 2 o'clock position when on the SE mount, so if I ever get it on the EQ mount it will be in the 10 o'clock position.

The sky was still quite bright, but the moon was up, so I switched it on and got the moon centred in the circles. 32mm eyepiece in the scope and - no moon.  Not totally surprising when just out of the box with no attempt at getting the circles in the right place. But there was moon-glow, and it was easy to move it about two fovs over and there was the moon.

Back to the finder for a quick tweak of the alignment controls. I'm sure there is a logical reason why it has three alignment screws instead of two working at right angles, but I don't know what it is. It took me a few goes to work out exactly which screw moved it where, but then I am particularly non-mechanically minded, and even I had got it centred before it had moved too far in the eyepiece.

SS align on moon - done.  Now for the fun.

I set the scope to take me to Venus. Before looking through the eyepiece, I had a quick look through the telrad. It was about at the edge of the middle circle. So I centred it. Quick look in the eyepiece and there was Venus. At this point I am starting to get impressed. Set up Venus as my second alignment point and there was not a lot more for the telrad to do. However, the instructions say that when you take it off, it will still be aligned when you attach it next time.

Any of you on the south coast will know what wonderful conditions we have had in the last week ...

Last night was my first opportunity to try. I attached the telrad as soon as I put the scope out to cool down, while setting up the rest of the gear. You wouldn't believe it - there are only two ways of putting it on and I managed to choose the wrong one. I only worked this out when I came to actually use it. Did I mention how I'm not particularly mechanically minded?

Centred Venus in the telrad and went for the eyepiece. Nothing except a faint glow on the LH edge. Move scope over a tad and there it was. I have to say I was a little disappointed at this point, but (as you will see) it was not really the telrad's fault. Anyway, another quick tweak of the alignment screws and it was again centred.

I decided I was going to attempt something I had never managed to do - A skyalign. The number of objects available was rather limited due to the brightness of the sky, so I opted for two planets (Venus & Jupiter) and Spica.  If you are going to test a system, you might as well give it a REAL test, yes? And it worked. By this time I was using my 12mm reticle eyepiece, so I had the objects properly (instead of guestimatedly) in the centre of the ep. Between Venus and Spica, the alignment was so good that every object I moved to appeared on the screen of my neximager (about 6'). When I moved outside that range (e.g. Saturn) a little accuracy was lost (not surprised at that), but just switch telrad on again, put object in centre of circle, and it was back on the screen.

I found it is important to set the brightness of the rings according to the object. For bright objects, I can have them at full brightness, but for fainter objects, they can drown out the point of light I am trying to align on. I am surrounded by streetlights and there is a zone of sky around each of them where, although I can see a bright object, I have learned that trying to do anything useful is a waste of time - the 'red zone'. A quick test on Regulus in this red zone last night showed me that even there the rings are bright enough to be seen.

When I packed up, I discovered why the telrad had been off when I started - the screws holding it to the base were not fully done up. I believe I did mention that I'm not particularly mechanically minded. In consequence, my original first night's alignment was undone by last night's adjustments, so I am back to square one and will require a further two nights to confirm the on/off retention of alignment (or I suppose I could align it, take it off and put it back on again in one session). Worst case scenario, I could just leave it on the scope - there is room on the shelf for the scope with it attached and the cover (aka bin liner) still covers it all. I'll see.

Overall impressions:
(1) I like the brightness of the rings and the fact that I can always see them no matter how close I get to the street lights. This was a MAJOR issue with rdfs in the past.
(2) Skyalign is a REAL hassle and I can't imagine why I would use it in future. This comment should be taken in conjunction with the fact that I have a fairly good grasp of the sky and can find a couple of stars I can name without too much difficulty.
(3) That said, centring objects in the ep/camera has just become orders of magnitude easier than playing with the wixey, getting the altitude about right and scrolling backwards and forwards until I "stumble" upon the required object [a major contributing factor as to why I have usually started with a single object align].
(4) If the goto is slightly out, I can now easily tweak the alignment with the telrad and add the new object as a new alignment point.
(5) If someone as kak-handed as I am can get it working like this, ANYONE can do it.

It may be early days, but I think I am willing to go out on a limb and say that this is probably one of the best £40-worths I have spent on this hobby since I started (with the possible excpetion of my 7x50 binoculars). 10/10 (but only because giving it 11/10 is cheating!).

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ollypenrice

ollypenrice

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Totally agree, an unbeatable spend. And don't forget the batteries. In fact I do forget them because they last so long I can never remember exactly where they go when I do need to change them. It is too early for me to comment on the life expectancy of a Telrad yet because mine has only been in service for 17 years...

Don't you wish Telrad made, well, everything you have in your observatory!!!

Olly

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niallk

niallk

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So good, I own two of them! - one for each scope. Rarely ever need to realign they hold so well between mountings on the baseplate.

I definitely agree - best value for money accessory for a scope.

Nice report :)

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cotterless45

cotterless45

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Best buy indeed . I've got three ! Try and keep the alignment bolts screwed in tight, saves realigning when you move the scope.

Keep both eyes for easy star hopping. In addition the download charts started me off with Messiers,

http://www.atmob.org/library/member/skymaps_jsmall.html

More than my finder scope ever did, hurrah !

Old Nick.

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Physopto

Physopto

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I altered mine as did a friend before me to use the main 12volt supply for dew prevention and stepped down for its led supply. So never need to worry about forgetting to turn it off anyway. It is a great device but desperately in need of size reduction. But most of all dew prevention ! It is very ungainly. In short I would not like to be without it. Better than anything else.

Derek

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Physopto

Physopto

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There is a thread somewhere on SGL with instructions to make a dew-shield for a telrad.  I suppose now I will have to go looking for it *sigh*

:)

You don't really need a dew shield. I have just fitted some resistors under the glass where it meets the main body. just drill two small holes and feed the resistor legs through the holes. insulate the legs in the body and solder on extension  wires take the wires to the front of the Telrad and fit two phono sockets there. Then you can drive the "heater resistors" from your 12 volt supply.  Just make sure that the resistors do not touch the glass. There will be enough heat generated from these resistors to keep the dew at bay. Off hand I can't remember the value of the resistors but just a bit of trial and error. Best to use 3 Watt resistors if possible. It is very cheep to do, Telrad dew heaters are silly prices.

Derek

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bish

bish

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To me it was like when I stopped using road atlas and got a satnav. I spent years saying how I don't need a satnav and a map does me fine. Then I finally got a satnav and use it all the time. I still use my 9x50 by side the telrad - but always start with the telard.

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Physopto

Physopto

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Yes I originally used a standard straight through 7x50 Finder scope Williams Optics. I found the straight though difficult to use at certain elevations. So I purchased a 14x80 with right angle viewing. It was purchased from TS, found it not to my liking as too large really. My own fault. Then bit the bullet and went for the Telrad after trying other makes/types, never looked back since. The finder scopes are used very infrequently now, but nice now and again.

Telrad Rules !!

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Demonperformer

Demonperformer

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You don't really need a dew shield. I have just fitted some resistors under the glass where it meets the main body. just drill two small holes and feed the resistor legs through the holes. insulate the legs in the body and solder on extension  wires take the wires to the front of the Telrad and fit two phono sockets there. Then you can drive the "heater resistors" from your 12 volt supply.  Just make sure that the resistors do not touch the glass. There will be enough heat generated from these resistors to keep the dew at bay. Off hand I can't remember the value of the resistors but just a bit of trial and error. Best to use 3 Watt resistors if possible. It is very cheep to do, Telrad dew heaters are silly prices.

Derek

I guess it's whatever is easiest for you. For me, I don't use a 12v supply, just plug everything into a mains extension lead, so setting up something like this would require the purchase of (another) transformer to get mains down to 12vDC, and take up another valuable socket. And I am really not enamoured with the idea of driiling holes in my beloved telrad.  I would probably end up drilling through something vital (I believe I did mention that I am mechanically-challenged). But if it works for you, that's great. I'm sure there will be others who will find your solution just right for them.

Thanks.

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Yearofthegoat

Yearofthegoat

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Couldn't agree more - my Telrad really made things so much easier. My main problem was the inverted image in the finderscope, and its narrow field of view, which meant I couldn't be sure I was centred on what I wanted - say, Alioth - in order to do a 2-star alignment for my HEQ5's goto. Once I got the telrad on I could get whichever stars I wanted to use to at least appear somewhere in the eyepiece and then, once centred the 2-star alignment became way more accurate and in turn this meant I could use the Goto as it was intended.

Definitely strongly recommended for beginners like me.

I'm glad it's not smaller - the missus would question the cost then ;)

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niallk

niallk

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That cute lil Telrad is mine..... but I'll admit the idea was shamelessly copied from another SGL member Bambuko, the credit is all his :p

I love it! Nice job ;)

I hope you didn't mind me adding a link to your thread.

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