Lightweight Travel scope

[Donkeiller]

Someone asked me to do a quick review of my Kson ED1026(102mm f/6 doublet).

I'd been looking for short, lightweight travel scope to "cover" for my Megrez 90 while it gets a replacement focuser.

The bare carbon fibre OTS weigh 5.7 lbs is 21.5" with dewshield retracted and 25.5" extended. Sits very nicely on my lightweight Synscan Goto mount and comes in a substantial padded case with CNC rings (see photos).

Saw the scope advertised on "UK Astronomy Buy and Sell" just before Xmas. The seller was visiting Cambridge for some Xmas shopping, so he suggested he brought it over.

Was as described- a few scuffs on the tube (subsequently removed with "T-Cut") and tested well in daylight.

Night was a different matter and it had slight but definite coma. Didn't seem to affect viewing, but I was not totally happy.

A borrowed laser collimator showed missaligned optics, so I bit the bullet and dismantled the scope. Once done it was clear that the lens cell was not seated properly. Having removed the cell (noting and marking the orientation!), I gave the lenses a careful clean and replaced in the original orientation, taking care to ensure the cell remained properly seated as I tightened the securing ring.

Next time out the star test was near perfect:hello2:.

It gives great widefield views and excellent planetary views- with typical seeing usually better than my (well collimated 6SE). Cassini is easily seen at x77 and I can see banding on the planet and ring shadow at higher mags. It is particulalary good at "doubles". I can resolve the "Double double" at x51 and get a clear split at x77 (next EP up).

For a "fast" ED doublet CA is surprisingly low. I can detect a hint on Vega and more obviously on Venus. The Moon doesn't show any to my eyes and there is none that I can detect on Jupiter, Mars, or Saturn.

One thing I really like is the robust 2 speed focuser which will rack smoothly up and down at zenith with no trace of slip. The downfall of the Megrez.

I'm getting the latest rack and pinion focuser, as a replacement, direct from WO in the next couple of weeks, so I'm looking forward to a "head to head" between the two scopes.

On current form the Megrez is going to be struggling!