I mentioned previously that I had switched over temporarily to a borrowed 12″ F/8 LX850 OTA. I didn’t mention that it was a prototype incorporating a proposed new feature – installation of a forced-air setup comparable to previous 7″ and 16″ LX200 models. I’ve been using it and trying to get a feel for how effective the cooling is compared to the three 12″ F/10 Meades I owned previously, though of course without a controlled, side by side A-B test the result won’t be definitive. The fan has been running during all of my imaging runs, to take advantage of whatever improvement there is.
The other night, I tried something different. I took a series of ten 5 second exposures with the fan off. I then engaged the fan and took ten more. Then I repeated both sets. That gave me 40 exposures, 20 each with and without the fan spinning. I knew that over such a short term I wouldn’t see any cooling effects but I wanted to establish that there was no more issue with fan vibration than in any of the other cooled Meade tubes I’ve owned. There was a lot of variation from frame to frame due to early evening urban environmental cooling effects so I examined the data in sets. I ran the sets through CCDInspector and derived the following FWHM values for each set:
first series without fan 2.26 arcseconds
first series with fan 2.32 arcseconds
second series without fan 2.46 arcseconds
second series with fan 2.38 arcseconds
average of all with fan 2.35 arcseconds
average of all without fan 2.36 arcseconds
I conclude from this that fan vibration is having no effect on star images.
Is the 14″ LX600 as steady and stable as the 14″ LX 850?….in a wind?….when focusing?…. So, in other words, Will the LX 600 have a bit more shake to it than the heavier LX 850…. or from your knowledge and experience, are they both equal in the “vibration-free category… Thank you for your thoughtful comments. They are important to me because I will shortly be choosing one of those telescopes….and I will let you know which I have chosen as soon as I make a final decision… Thank You, Travelenfree
Hello again!
There probably aren’t many who can address your specific question comparing the 14″ LX850 and LX600. Neither has been around very long and I’m not aware of anyone who has owned or extensively used both. I’ve seen the LX600 but have not yet had an opportunity to use one. Living in an area low in astronomer population, I don’t expect to be able to play with an LX600 any time soon.
I did own and use a wedged 14″ LX200GPS for a few years and that was a decent imaging platform but didn’t like wind very much. I’m at 41 degrees N. I know that some folks farther South experience fork arm flexure when tilted way over on a wedge. I believe the LX600 fork arms to be more substantial and I would expect them to be better; I can’t prove it, though.
The LX850 with the AT12RC (similar in weight and size to the 14″ LX850 OTA with dewshield) handled a modest breeze OK but hated gusts over 20 mph. The LX600 might be a bit better or worse.
I am seriously considereing the purchase of an LX850 or LX600, 14″ from Woodland Hills Camera and Telescope Will the new ones come with a fan? Farrah told me that she already has each of those in stock. But, I want the one with the fan, so I guess that I will tell her that I will wait for the one with fan. Also, is there only one fan on the scope? One more question, I do 80% observing, 20% astro photography from my yard in Southern California. Do you recommend the 14″ LX 600 or the 14″ LX 850 for my p0urposes. Thank You.. I will await your meaningful response. Travelenfree
The prototypes of which I’m aware (including this one) use the same scheme as previous fan-equipped Meade models (7″ and 16″ LX200 series). They incorporate a single rear fan and a single rear vent.
This differs from the former RCX (and current Max) models, which used, I believe, two rear fans, both blowing inwards, and passive front vents.
I’m fairly certain that no decision has yet been made regarding the introduction of the fan into production models.
For visual use, I really like the convenience of an alt/az forlmount. For mixed use, that would require mounting/unmounting the wedge depending on the purpose of a given session so the convenience would be somewhat reduced. Leaving the wedge on full time would be easier, and a wedged forkmount is nearly as convenient as alt/az. For imaging, both the GEM and wedged fork have advantages. The GEMs usually have easier-to-use mechanical adjustments for polar alignment; not too important in a fixed setup but nice for frequent use, as in a field setup.
That’s a long answer! The short answer? For 80/20 visual I’d lean toward the LX600 – unless you think the proportions might swing the other way.