Astro systems 150fg strip and build

[LeeB]

Just took apart and rebuilt a late eighties ? 150fg 1/8 wave astro systems newt i picked up on ebay, I have then retested the optics on planetary and deep sky, so I would like to report my findings.

optics                     superb ( nice markings on mars and saturn showed cassini sharp and cloud markings, stars sharp with little coma at edges, m13 well resolved

                              outer nearly to core.  came pre centre dotted and coating still afew years left yet, cleaned well.

secondary/spide    a two arm spider with only push/pull and rotary adjustments, tilt achieved by utilising spider tube fastenings.

                              a three point support would have been easier to adjust but the systems works so left as is

primary/cell            no spring system, three point nylon support and three cirum nylons, retaing clips holding mirror in.

                              difficult to collimate, requiring cell removal to loosen then check retaining clip adjustment after collimation. requiring care to not disturb colli.

                              I will alter this to a three sping support soon.

tube                       lovelly and round with well blacked interior.

focuser                   0.95 and 1.25 adapters fit, push pull and rotary fine adjust. a superb piece of kit that is staying.

mount                     altaz teflon bearing with tension adjustment, a superb dob on a stick feel, similar to az4 feel, remarkably smooth and i like the twin large

                               knurled knobs to allow the tube to slide over 3 inchs to compensate and balance.

overall                    a great grab and go scope not heavy at all, 8kg with mount easy one hand carry, finder was changed for a red dot and while                                                     collimation is a little tricky it locks well.

                               , its a keeper great design apart from the cell and performance is great with the david hind 1/8th mirror  

[John]

I used to have one of those back in the early 1990's - great scopes 

The optics were made by David Hinds I believe and are of excellent quality. 

Nice to see a report on one. The white tube looks very smart - mine was the hammered grey colour.

[LeeB]

yes its surprisingly good. aparently they made two specs one with 1/6th optics and the fg150 with 1/8th optics, it also seems to be fitted with the option rotary focuser, instead of rack and pinion.

[dweller25]

I had the 8.5" version - with the rotary focuser, mine was Silver Hammer finished.

I discussed the primary collimation with Rob Miller - he designed the system so that once the plastic grub screws were set it stayed in perfect collimation - which it did. I never had to adjust my primary even after 20 years of use.

I should never have sold that scope !!

[LeeB]

on reflection you are probably right, I may leave the cell as is, as it had not been touched ever in 25 years from new and was nearly in perfect colli on arrival, only being removed to clean.