Star Diagonal

[West End Wendy]

Hi. I've never been entirely happy with the star diagonal on my otherwise superb SW ED100, but having never owned a telescope before this one I'm not able to judge whether it's actually faulty.

Is the barrel on a diagonal supposed to rotate within its socket so that it moves even when the thumb screws are tight? Mine does (and makes a slightly alarming crunching noise when doing so).

The barrel on my diagonal also falls very slightly out of its socket, producing an annoying image shift when it does so. I assume this is not supposed to happen?

Thanks in advance for the help.

Cheers,

Tim.

[steppenwolf]

Is the barrel on a diagonal supposed to rotate within its socket so that it moves even when the thumb screws are tight?

No, it shouldn't do this.

The barrel on my diagonal also falls very slightly out of its socket,

As above - you need a new and better diagonal methinks!

[dmahon]

Televue make a good one

[glowjet]

Unless you want to invest in a new one, these regularly appear on the s/hand market, you should be able to obtain one with a dielectric 99% reflective mirror for between £40 and £70 depending on the make and size 2" or 1.25", be careful using the one you have in case it falls apart with an eye piece in as it sounds very unsafe to use. Whatever you do, buy good quality makes and go for a 2", if one crops up at a reasonable price.

[russ]

The Revelation Dielectrics are good and currently have an extra 10% off, making them the cheapest brand new but decent option.

[West End Wendy]

Thanks for the advice everyone.

That Revelation looks great and is in price range.

Thanks,

Tim