Problem with my new EM-11 Temma 2M in the Sourthern Hemisphere
The EM-11 is designed to be used in the Northern and
Southern hemispheres and is highly adjustable. There are a few difficult
issues that I encountered that may be of interest to others. I purchased a
early serial number unit (#32) that had problems with its electronics in
the Southern hemispere.
The EM-11 tracked and had normal Goto function in Florida where I tested it before I went to Australia. When I went to the Queensland Astrofest in 2010 outside Brisbane, I switched the motor drive selector switch on the hand controller from the "1" position for Northern hemisphere sidereal rate to the "A" position for Southern hemisphere sidereal rate. I changed the time zone on my Windows 7 laptop from GMT -5 in Florida to GMT +10 for Brisbane and changed the location in TheSky6 Professional program from Gainesville FL to Brisbane, Australia. The EM-11 tracked beautifully (including autoguider interface). However, when I tried to establish a link with TheSky6 Professional via the USB-serial cable and the Temma driver for GOTO, I got an error message on TheSky6 panel and a warning not to connect "or the mount could be damaged." On the second night of use, I ignored the error messages and went ahead and selected the "establish link anyway" option. When I selected the choice, I lost power to the mount immediately. The 2A fuse in the power line from the battery to the mount had blown when I had tried to "establish a link" via the serial cable. Presumably there was an overload in the Temma 2M electronics and motor system.
When I returned to Florida, I replaced the fuse in the powerline, reset the software, computer and drive selector switch for Northern hemispere function. All worked well. However, when I was testing the unit indoors and connected the EM-11 to a Pyramid 12V power source (runs at 13.8 V), I had the Temma 2 electronics completely fail. The mount was sent back to Takahashi for warranty repair.
When I received the repaired unit back from Takahashi in Japan, the EM-11 worked perfectly with TheSky6 Profession in both Northern hemisphere and Southern hemisphere function. It connected without error message and slewed normally during Goto function. I don't know whether the Temma 2M electronics in my early model unit had a defect or whether there was a problem in the firmware for operation with TheSky6 that has subsequently been resolved in newer EM-11 units and in my repaired unit.