these days I bought a Meade 305 OTA for a very low price. OTA was full with scratches and chips, but optics are clear and superb, as a quick star test showed.
In my last 20 years of collecting scopes, I have around 15 of these Towa 339 clones, and so i wonder, if this Meade modell will show really 80 mm free aperture ( the towas 339 I had, did ).
So I made the clear aperture test - and there was "only" 76 mm free aperture
not really a problem, but I was mad enough to rhink again abaout an OTA extension ( made that a long time ago and showed it here on CN ), but : I was a bit lazy these day - again buying an alu-pipe, again starting the lathe, again painting, again drilling and cutting threads ??? Hm...I'm so tired....
Well ...and as I taje a closer look to the Meade OAZ I saw that this is the type of OAZ that is screwed in the end-ring of the OTA ! In the past I have also Towa 330 clones that had the OAZ in one peace....but this one is screwable !
And as I look at the inner thread of the end.ring I wonder if its could be M68 ???? Trying to fit some M68 adaptors..and voila ! They fit !!!!
So it was a quick job for the OTA "extension" . I added 120 mm with M68 rings as shown in the pics, also cutting the inner fine-tube. Made new clear aperture test : and we have 80 mm free aperture !
Painting the OTA new ??? No...this time short ways and quick solutions : so I foiled the OTA with a nice white shining foil and it looks like new.
Meade 305 reloaded for quick-time moon-watching I still like these old japanese guys ! Must be from around 1978 I guess, no spacers, but the "modern" PET distance ring between the lenses. Very sharp and nice optic !
Kind regards from good old germany, yours Michael Aaron
Edited by AaronM, 14 December 2018 - 03:16 PM.