16.3 V Power Supply for Losmandy Gemini

My G-11 performs quite well and I am very happy with it, but I do note that despite careful balancing I occasionally get Dec or RA Heavy Tr warning messages.  I've read numerous times in the Gemini forum that these mounts are a bit under powered at 12-13 volts from a battery.  The Gemini system can take up to 18 volts, but most users seem to recommend 16 volts.  The Losmandy power supply provides ~ 15 volts from 110 V AC, but I prefer to operate my astro gear from battery power even in the observatory.

After scouring the internet I came across a regulated DC converter that increases ~ 12 volts to 16.3 volts and can handle up to 6 amps.  The device is sealed and is available on Amazon at a reasonable price.     Here is the back of the device.

Here is the front of the device.  I've used wire nuts to connect a 12 v accessory power plug (cigarette lighter plug) to the input wires.  To the converter outputs I've used wire nuts to connect the Gemini power plug with the 2.1 mm right angle plug.

When plugged into my battery, the output to the Gemini unit reads spot on the advertised 16.3 volts.

Here is the finished unit attached to the side of the pier with heavy duty Velcro.

I'll be curious to see if my G-11 performs any differently and if I get the RA or Dec Heavy Tr warning messages.

August 20 Update

While we had over 9" of rain over August 11 & 12, and the yard and street flooded, we were spared any damage to the house or observatory.  The worst of the rain was North of Lake Pontchartrain and West of I-55.  Many thousands  of people have been impacted, many without flood insurance.  If you are able to help, please contribute to one of the many charities and volunteer organizations that are providing aide.

Unfortunately the weather of late has not allowed any viewing but I hope to get back out under the stars in the very near future.  I have been able to complete a few small jobs in the observatory; installing foam insulation strips around the doors and building shelves in the office.

I recently learned from veteran video astronomer Ken James about a site that shows sky darkness around the globe based on satellite video infrared imaging.  The site is  http://www.lightpollutionmap.info/ and I really like the maps.  The color coding for levels of light pollution, at least in my area, appear reasonably accurate.   There is also the option to display light pollution based on user submitted Sky Quality Meter readings, although this option didn't offer any data in my area.

August 5 report

Earlier this week I updated one of my favorite astronomy software programs Deep-Sky Planner to version 7.  I've used this program for several years to plan my observing sessions and to record my observations.   I find the program exceptionally easy to use, full featured, reliable, regularly updated, and very well supported.   I've considered writing a review, but I've found that Rod Molise has penned very good reviews on his blog and in Sky & Telescope  magazine July 2015. If you don't use planning software or if you use a different program, give Deep-Sky Planner a look.

Aug 5 - A very warm & humid night but after an afternoon thunderstorm the skies are remarkably clear. Only a few spotty clouds. The rain cooled off the temp (it is 78 now at 2100 hrs). Mosquitoes are thick and I have the Thermocells going but I've already been bitten once.

My plan was to work on a drift alignment of the mount.  Since mounting my G-11 on the pier in the observatory I've used the polar scope to align, but I do observe image shift between 90 second exposures.  For this setup I'll used my Mallincam with no focal reducer or Barlow.

I followed the instructions written by Ray Shore and posted on AstroPhotography Tonight.  This was my first attempt at drift alignment and I approached it tentatively, making small adjustments, measure the drift, tweak some more, remeasure the drift, etc, etc, etc...  I did find settings that resulted in no perceptible drift for over 5 minutes, but after aligning the altitude and returning to check the azimuth, the drift had returned.  This back & forth went on for hours and frankly I'm not so sure that my final alignment is any better than when I started.   I'll revisit this process at my next observing session and hope to home in on a more stable alignment for my mount.

July 16 Observing Report

July 16 was a hot, humid, but clear night.  Some clouds were present in the east but the sky was mostly clear with no star twinkle evident.  Sky meter reading at 11:30 pm was 18.24 mpsas or 4.17 nelm.   I spent some time trying to capture a decent image of Mars and Saturn but the planets were dancing such that a crisp focus was not possible.   This is the best I got with my VRC-10 operating at its native F8 and with a Televue 2" 2X Barlow lens bringing the optics to approximately F16.

The seeing South Louisiana in the summer is not great.  So I will keep trying, hoping for a night with clear skies and stable atmospheric conditions before Mars & Saturn fade into the west until next year.

I did enjoy some lunar viewing.  At F16 the moon's violent history is nicely revealed.  Even some craters house craters.   I'm not a lunar maven so I'm not sure of the surface location of these images.

In more recent nights, the sky has been largely cloudy such that even the the full moon is partially or even fully obscured.  So for now my telescopes sleep, dreaming of clear skies.

 

July 4 Observing Report

After the hamburgers and hot dogs were consumed and darkness fell, Heather and I slipped out to the observatory for a quick viewing session. Heather discovered she only had 6 Messier objects left to observe and they were the ones in Scorpius & Sagittarius we had looked at on July 1 but she had neglected to log them. So on a hot, humid, but clear night with decent seeing (no star twinkle and no planets dancing in the eyepiece), we observed Messier 4, 6, 7, and 80. By 10:00 pm Sagittarius was high enough for her to see Messier 69 & 70 at the base of the “tea pot”, and she was done! We capped off the evening by taking a quick look at M57 & M13, and then called it a night.  I checked the sky quality at 22:40 and got a reading of 18.78 mpsas or a limiting magnitude of 4.60 and a temperature of 81 F.

Congratulations to Heather for completing her observations of the Messier objects!

July 1 Observing Report

My daughter Heather came over around 10 to view on a hot and humid night . I threw in my polar scope and adjusted my polar alignment as my go to  & tracking has been off. It was pointing a bit low and to the SE. As Heather was over, I didn't take the time to drift align as I have been meaning to do, but instead jumped into viewing.

We started with Saturn and despite the humidity and high temps, we were rewarded with unexpectedly decent, but not good, seeing. While surface features weren't clear other than 1 equatorial band, we could detect a graduation in the brightness of the clouds from the pole to equator we also could detect the Cassini division between the A & B rings. At first we weren't sure we were seeing it, but as the seeing improved the dark band ~ 2/3 out the ring from the planet became prominent. With a 2.5X Powermate and 11mm eyepiece (EP) the focus became a bit soft but not bad, but the 11 mm EP provided the best views.

We then embarked on a mini-marathon of almost all of the Messier objects in Scorpius, Sagittarius, Ophiuchus, Lyra, Hercules, and Cygnus. We tried the Trifid and Lagoon nebulas but they were nearly imperceptible from the background in our mag 4.5 skies. So we focused on the star clusters, of which there are many in this area of the sky. Messier 13 & 5 were especially nice. At my scope's native F8, I found an 11mm EP provided the best balance of image scale and detail. At F10 Heather was using 15 mm and above EP.  Comparisons between the two scopes were virtually identical. At a bit after 1 am we called it a night and closed up the observatory.

My adjustment to the polar alignment seemed to help but I still need to drift align.  A fun night under the stars.   

Texas Star Party - Nope, not this year

I've been hoping to attend the Texas Star Party for several years now, but other priorities kept us from it.  2016 was to be the year and as luck would have it, on March 10 we were selected to attend and awarded a spot for our RV!   We plan to attend for the full week to get the most out of the experience.  In planning the 944 mile trip (by far the longest trip we have ever made pulling a trailer) I decided to limit travel to about 4 hours per day.

So we planned to travel to Beaumont, Texas on Day 1, then onto San Antonio on Day 2.  Day 3 brings us to Fort Stockton, Texas, only about 1-1/2 hour from Fort Davis and the star party.   So a 4 day trip each way plus 7 days at the star party, a 13 day trip !  Downsides are that the timing would require us to leave on April 28, our eldest daughter's birthday and also we will be away from home on Mother's day, so my wife will miss having the day with the kids and grand kids.

It was a big job to tear down the scope and empty the observatory and pack it into the back of my truck.  I was worried it might not all fit, but it did.

The hatch even closed !

The trailer was packed and ready to go.   Ok, I did need to pull in the slide and and fold up the steps.

As April 28 came, the weather forecast wasn't looking good through Texas or Louisiana.  I didn't look forward to hauling the trailer in hard rain and especially high winds.  We decided to postpone leaving for a couple of days to allow the threat of severe weather pass.   Besides the weather forecast for the Star Party calls for rain on Sunday and Monday, so I likely will not miss any observing time by arriving on Tuesday.

As Saturday came, the weather didn't improve and the forecast for Sunday wasn't any better.  Monday looked like it might be an OK travel day but that would have us arriving Wed night, IF I could make it in 3 days.  Would I have the stamina to drive all day and set up and then view?.  Six  travel days for 3-4 nights viewing, assuming good weather at the Prude Ranch, is not a good ratio for such a long journey. So we reluctantly decided to cancel the trip for this year.  On a positive note we will still get to attend a star party: the Deep South Spring Scrimmage.  It is only 1-1/2 hour drive away and the weather forecast looks promising.  Hey, the truck and trailer are already packed !

This post was written on May 3-4, 2016 but I overlooked posting it until now.