4 replies to this topic

[orion61]

  I own an LX-200 Classic 8" F6.3. It has the EMC coatings and has kicked the pants off of any Classic C8 it has been tested against.
The EMC series are the best optics of any Meade tubes I have owned. That means a lot of SCT's in my 62 years of life.
I also own a 1975 Sandcast C8and an American made C11 the 8" is very close optically but my LX edges it out, even on planetary details.
I love the Classic series, I have had 2 Autostar Meade 8" scopes and they are good, but the Classic will be with me until the Reaper takes me away.
  Are there any other stories like mine out there?
Cheers,
Duane
 

[Astro-Master]

I have a Meade 10" LX 200 I bought new in 1992 with the EMC coatings, it was one of the first XL 200's made, it only had a one star allignment, and the star images inside and outside of focus look identical to my eye.

 

I just have the OTA now and is used on my CGEM II mount, but I liked the fork mount better.

[MTibb]

I have the 10" f/6.3 EMC model, purchased new by my wife's uncle in 1993. At age 76, he felt like he couldn't handle it anymore, so he gave it to me in May of 2022. While I've never had a similar sized SCT to compare it to, I absolutely LOVE it! Not only are the optics wonderful, but the mount still operates perfectly without any capacitor issues or anything - perhaps because it was never run using the AC adapter. I control the goto's using SkySafari with the Astro-Gadget BTLX200 Bluetooth adapter... Works perfectly!

[orion61]

I have the 10" f/6.3 EMC model, purchased new by my wife's uncle in 1993. At age 76, he felt like he couldn't handle it anymore, so he gave it to me in May of 2022. While I've never had a similar sized SCT to compare it to, I absolutely LOVE it! Not only are the optics wonderful, but the mount still operates perfectly without any capacitor issues or anything - perhaps because it was never run using the AC adapter. I control the goto's using SkySafari with the Astro-Gadget BTLX200 Bluetooth adapter... Works perfectly!

I have always run my LX200's off of a 12 volt battery. The actual truth about the Caps blowing were from the awful A/C to D/C power 19V supplies. They are un-regulated hunks of junk. they would spike and caused most of the problems. I know of no problems if running on 12v. Meade boosted the slewing speeds by simply boosting the power to the D/C motors from the designed 12V to 19V. 
  There is NO way I will ever sell my EMC LX-200.
I have also had a 10" F10, and a 12" F10. Both of those were great but the 12" simply blew away any C11! It was so well figured I sketched Ganymede, as the seeing was graced by unusually good Midwestern skies. The next week showed my eyes through a binocular viewer showed the same detail as photographed by the large telescopes of the time. I remember posting it here at the in the mid 2000's. Alas it was just too heavy..
Thank you for viewing and posting here!

[Skywatchr]

I have always run my LX200's off of a 12 volt battery. The actual truth about the Caps blowing were from the awful A/C to D/C power 19V supplies. They are un-regulated hunks of junk. they would spike and caused most of the problems. I know of no problems if running on 12v. Meade boosted the slewing speeds by simply boosting the power to the D/C motors from the designed 12V to 19V. 
  There is NO way I will ever sell my EMC LX-200.
I have also had a 10" F10, and a 12" F10. Both of those were great but the 12" simply blew away any C11! It was so well figured I sketched Ganymede, as the seeing was graced by unusually good Midwestern skies. The next week showed my eyes through a binocular viewer showed the same detail as photographed by the large telescopes of the time. I remember posting it here at the in the mid 2000's. Alas it was just too heavy..
Thank you for viewing and posting here!

Yep, that Meade unregulated AC - 18vDC adapter killed many of these.  I have always use a regulated AC to 16vDC adapter, which is an old IBM Thinkpad power supply (3.36A or 4.5A rated) that even has the same DC plug for the Meade. That is when I am around an AC power source.  And a Scopestuff 12vDC to 18vDC adapter in the field to keep up the initial (slew) startup motor torque.  Although 12vDC will work just fine as long as you step the slew speed down a notch.  However I always encourage as a minimum to change the Tantalum cap in the handbox.  Why?  Because the Tantalum crystals deteriorate over time and can still pop their top at even 12v. The 18v versions used 25v rated caps so I always install double the voltage rating, which would be 35v for the 18v version. If I have 50v versions on hand, it doesn't hurt to use them.  Electrolytic are fine to use.  You can go higher in voltage rating of capacitors within reason.  The handbox ribbon cable is a precious component that needs the protection from getting a hole blown into it.  Like the old saying goes, "An ounce of prevention..."

Note some will argue about Tantalum caps, but NASA has done extensive research on Tantalum crystals.  In power circuits, the life expectancy of the voltage rating drops with age depending on their position(s) in the circuits.  In lower power circuits, such as at signal level voltages, it is no issue whatsoever.  So the rest of the Tantalum caps in the Classic, outside of the power circuits, are just fine to leave them be.

A 12v car battery, or other lead-acid battery at full charge is 13.8v, which is just fine.  They also have plenty of current (amps) reserve so they are more than enough. 

The electronics will only draw enough current that they need. A battery, or other power supply does not "push" current so overkill is just dandy and desirable.