Telegizmo 365 Scope Cover
I have been observing for about 10 years now and am located in
San Diego, CA-USA.
Chronology Four
years ago:
The reality of the newly acquired TMB Optical 229 scope was
starting to settle in and the views were outstanding. The scope / mount
is setup in a "roofless observatory" (atrium). For protection of the
scope while not in use, I started off using several Mylar emergency
blankets (intended for hikers). They are light weight and reflect the
sun's rays but are very thin and tear easily. The big problem with
their use is it would take upwards of 30 minutes to get them into
position and properly tied down. It was obvious this was not a good
method not only due to the time consumption but I was not going to
place my trust in these come the winter's high winds and storms.
My next try was to contact a local marine supplier that made
custom covers for boats. He suggested some materials for the outer and
inner liner and I provided the dimensional specs. In a week or so I had
a nice waterproof cover, albeit large. It was like a circus tent draped
over the scope and GEM. To put the cover in place required climbing an
8 foot step ladder. After almost falling over three times that was
enough for me so the search for a new cover was begun.
A fellow astronomer recommended Telegizmo covers. He mentioned
they used a material used by NASA in space flight. I checked them out
on the web and was impressed. One concern was the covers being one
piece and if they made one for the TMB-229 in a similar manner I would
end up with another large and unwieldy circus tent. I gave Telegizmo a
call and discussed the project with Bob Pitney, the company founder.
Luckily, Bob is a great guy and loves a challenge as well as pleasing
customers. I had in mind a 3 piece cover that would be similar to the
emergency blankets I had used but would be more custom fit and
substantial. The concept was to cover the gear with three covers,
scope, GEM and weights / counterweight shaft. By putting the covers on
from bottom up and having overlap, the equipment should be
protected. The sectional covers would be easier to handle. Bob grasped
the concept quickly and asked for a simple set of drawings. I made the
measurements and sent them off to Telegizmo. The most complex shape was
for the GEM, it looked pear shaped and Bob quickly dubbed it the
beehive. After a week or two the covers arrived. The material is
waterproof and an silver color to reflect the heat. The three piece
cover concept worked, placing / removing them was breeze and I never
felt like I was going to loose my balance on the ladder.
After a year or so of use I was satisfied with the cover but
the intense southern California sun eventually took it's toll and they
were beginning to disintegrate. This was not a surprise as Bob
mentioned eventually this would happen. I had resigned myself to
replacing the cover every 12 to 18 months. Keep in mind the So. CA. sun
is so intense
the mylar emergency blankets end up shattering after a month
or two outdoors.
Two Years Ago
Enter the 365 cover. Telegizmo had several request from folks
that leave their scopes outdoors 365.25 days out of the year. Given the
market demand Telegizmo researched and tried out various materials.
After Bob was satisfied he had a winner he brought this new product to
market. It is intended for scopes that are outdoors continuously in
harsh weather including blowing rain, snow and blistering sun. This was
what I needed (all but the snow, you can keep that thank you very much).
I placed an order for this new product having complete
confidence in it owing to the testing Telegizmo performed prior to
market introduction. This time I also upsized the scope cover so I
could include a guide scope as well as CCD camera with focuser extended
to the focus position and dewshield extended. I wanted to be able to
astroimage all night and quickly cover the setup before setting off to
work in the morning. Mind you this would have to be fast, convenient
and protect the equipment. In discussing it with Telegizmo they were a
bit anxious about this much equipment under cover but I told Bob not to
worry, I wouldn't hold him liable should my experiment fail. A couple
weeks later a new 365 cover arrived. Again it is made in the three
section scheme. The scope section is huge because of the extra room for
guide scope and CCD imager.
The cover is a two layer affair. The outer layer is a
waterproof weave material of some sort; the weave is to tight for water
to get in, even when blasted with a water hose. The inside liner is the
silver colored material used on the original covers. Since this inner
layer is protected from UV by the top layer, it will last essentially
forever. The silver color is supposed to reflect the heat even though
it's inside now. Since I have guide scopes and many other places to
snag this material I asked Telegizmo about a soft felt material
instead. Telegizmo was kind enough to oblige the customer (customer
service is
high on their priority list). The outer material does add more
weight, I would guess the 365 cover is twice as heavy the original
Telegizmo. It's not so heavy that one feels you are fighting it, simply
put you have a little more weight to deal with. In my years of using
this cover I have not felt I was loosing my balance on the ladder.
Closing up the equipment after a night of imaging goes quickly
and without pain. The dew on the scope must be removed before placing
the cover on. I have my scope polished with a polymer based polish and
the dew is easily toweled off. The covers go on in order,
counterweights, GEM then scope. There is plenty of overlap between them
therefore rain goes from the top / outer cover to the next lower cover,
similar to shingles on a roof. Even with blowing rain, water has not
been able to work it's way beyond the overlaps and into the equipment.
The next night setup is very easy, covers removed (gravity assists this
part nicely) and the mount is moved to the park position. That is,
after imaging, the CCD Commander scripts park the mount. I have it set
to put the scope in a protected positon but not the position intended
to be covered. The scope is manually moved to park and the CCD
Commander start-up scripts take care of re-syncing the mount and
establishing precise focus.
The 365 cover is a cream-white color and not the reflective
aluminum. Originally I had some concerns about this but after several
summers of experience it turns out the scope only gets warm to the
touch after being in the summer sun. If I pull the cover off the scope
as soon as the sun is set enough to put the scope in shade, it will
reach ambient temperature by nightfall. An image of the cover in place
is included below.
The big questions were would this cover hold up over time and
afford full protection to the equipment? Short answer is a resounding YES
to both concerns however since I have had several years to evaluate the
cover the details deserve mentioned.
Protection: Over the years, the scope has
endured the elements without any harm. One original concern I had was
the objective getting dewed up when covered. If this happens frequently
it's obviously not good for the optics. When describing my setup some
folks recommended a small light bulb under the cover to prevent
moisture build up. I was hoping this would not be needed due to the
possible fire hazard. Luckily the moisture buildup is not a problem and
the objective is not subject to dewing. I did have a problem once when
I put the (original) cover on the scope while it was still wet with
dew. The objective ended up dew covered. I sent Bob an email to ask
(his opinion on his opinion was of this) as I thought the excess
moisture would eventually escape and not zero in on the objective. I
was very surprised when he quickly called back to discuss this. He was
very concerned the customer is always happy and after a time he figured
out the problem was in the dew on the scope. He suggested taking the
cover off, folding it inside out and
letting it dry thoroughly for a couple days. I was very
impressed with his quick response and resolution. I did as advised and
since then, always dry the scope before putting the cover on and
trapped moisture has never been a problem since. Little did I know the
magnitude of the ultimate test of this cover.
A couple October's ago, on a nice Sunday afternoon I was
visiting Palomar Observatory. On the ride back down the mountain I
stopped at various overlooks to take in the southern California
landscape. Looking East a small fire was throwing up a large smoke plum
blowing west and blanketing parts of San Diego county. On the radio,
folks downwind were talking about how bad the smoke was. I did not give
the fire much thought even though I was due west of it and the winds
were from that direction. Well, the next day the winds had kicked up to
60 MPH and the fire moved like a freight train through the night. The
order came in early to evacuate and with the thick smoke and reddish
horizon it was time to bail. There was no way to do anything about the
scope other than hope for the best. One of the big problems with these
sort of fires is the strong winds send embers a long way. Had the scope
cover been a thinner material I would be really worried, as it was, I
was only worried. It took a couple days but the brave firefighters got
things under control and I was able to return home. I was happy to see
to scope cover was intact and no harm had come to it. There was a lot
of fine ash everywhere, kicked up by the wind. The 365 cover was
"covered" in ash but I recalled Bob mentioning one could hose this
cover off. When it came time to clean the cover this is exactly what I
did, just hosed it off with a water hose and gave it a couple days to
dry. When I was finally able to pull the cover, none of the ash had
penetrated the defensive shield of the Telegizmo 365. The gear was
clean and shiny as if nothing had happened. Now one has to understand
the magnitude and aftermath of the southern California wildfires. The
blanket ash can be 1/4" deep and take months to finally clear away. The
sky was useless for astronomy, even the folks at Palomar made that
comment. In my case the wild fire had come to within 1 mile. More
trivial weather problems, like Pacific storms with downpours and
blowing wind, the cover just shrugs these off. The equipment underneath
is protected; I can sleep at night without any concerns.
Longevity: I have had the Telegizmo 365 cover for three years
now. To date I can not detect any degradation of the material. The
internal material is also holding up and looks as good as new. I am
very careful about sharp edges on the scope / GEM and protect the cover
from these. With care it looks like this cover is going to last a very
long time.
Some things I've learned to protect a scope that lives
outdoors follows.
1) Wax everything, a polymer wax with UV protection is
recommended.
2) Before putting the cover on, towel off any dew on the
scope. This
is where #1 above makes removing the moisture easier. The
moisture
won't end up under the cover where it will become a problem.
3) If possible seal the scope tube. On the TMB 229, I taped
the lens
cell to the flange which sealed the front part of the tube.
This
eliminated one area moisture could enter the tube. The focuser
on the
classic CNC tubes is easily sealed with a giant o-ring on the
focuser
draw tube. A Particle Wave Technologies end cap with desiccant
packs
removes any moisture that got into the tube during use. In my
case, the
desiccant will last several weeks before needing changed,
therefore I
know the scope is sealed otherwise the packs would exhaust
themselves
sooner.
4) Most important get the Telegizmo 365
