Posts Made By: Dan Goldberg

Have you considered laser treatment?

I like the per-ad support. It's what I've been waiting for, plus orange seems to look very good on me

As for $60 for supporting Astromart, remember that's only for 6mos.

I believe you're looking for www.astroshaman-sundance.com

It's an easy DIY project. Why pay money when the parts are practically free?

The FOV quoted on eyepieces is the apparent field of view. The actual field of view can be approximately calculated by dividing an eyepiece's given apparent field of view by the magnification with that eyepiece.

Wider is better, isn't it?

Yoink. Hope you don't mind if I make that my desktop image!

I made my own out of discrete resistors. It's very easy to do even if you know nothing about electronics. Take this formula:

P = I*V where V=12V. P is the power you want, say 2W. Use that to calculate your current, I = .16A

Now you can use the formula V = I*R to calculate your resistance. In this case, R = 12/.16 = 72 Ohms.

So you want a total of 72 Ohms worth of resistance to generate a total of 2W of heat. So, here is where some drafting skills or a knack for putting things together comes in. I used, as I mentioned, discrete resistors. You could to that and solder them end to end as I did or you can try to get a length of nichrome wire that's perfect for your objective at around 72Ohms in total resistance. If you pick discrete resistors, which is probably harder to implement you need to be mindful of each resistor's power rating. For example, if you choose to make your heater 9 resistors in series (as I did) then you need to divide 2W/9 to get 0.22W power dissipation per resistor and 72 Ohms/9 to get 8 Ohms per resistor. Find whatever you can that's close, or change your design slightly to accomodate what you can acquire easily. I chose 9 for the exact reason that most resistors can safely dissipate about 1/4W of power and I had access to something around 8 Ohms.

After I measured and soldered everything together I attached a wire lead and I put it all in a length of heatshink tubing for electrical insulation.

To make a heater block instead of strip, you can use a single sand filled type, high power resistor instead of a strip of smaller ones.

You can make a very simple control box too. In my case I just used a couple switches, a couple LED's, a project box and a tangle of wires If you wanted some easily controlled heat output you could use a rheostat, for example, to dissipate some power before your heating srtip or blocks. Design the strip with your maximum power requirements in mind and use the rheostat in series to reduce the total power output as necessary. Rheostats are fairly expensive though, so keep that in mind. Remember also to calculate the power your rheostat will drop so that you don't overload it!

EP heaters are hard to make becausae you're always moving your EP's around. You could make an aluminum plate with 1.25" or 2" (or both) holes in it and place resistor blocks around the holes, or you could wrap insulated nichrome wire around the holes, or you can do what I do and use your hands to warm your EP's

Depending on your telescope and whatever CCD setup you choose, a serial port, a parallel port, a USB port and a PS/2 port are good ideas. You may not use all of them. Fortunately, most notebooks come with them all, but double check.

As for the components, probably anything from within the past 5 years would be about as good as anything else depending on what else you want to use the laptop for in addition to the aforementioned.

Brand? I've tried IBM, Acer, Toshiba, Fujitsu and Sony and I own an IBM... Too bad you can't custom build your own notebook like you can a desktop!

I have them all, except under the Skywatcher brand name. They're all from the same place.

Generally very good eyepieces. They suffer from some serious ghosting/internal reflections, it seems to me, when viewing bright objects like Jupiter and Saturn, for example. I also think the eye relief is less than claimed. Other than that they're very well worth the money. Large and very usable field of view. Nice, sharp images over most of the field with just a little loss of focus at the edges. Good build quality too.

I don't know if you'll be able to find a "low priced" GoTo system for the EQ-6, but from everything I've seen it's an excellent mount. There are GoTo systems out there for it, but they're very (in my opinion) expensive. I don't know if there are any DSC's out for it, but that might be a viable, less expensive alternative should any be available.

In the case of the C925 you could probably save some money and get the HEQ-5. It will be plenty for visual observing and some poking around with photography and a hell of a lot better than the CG-5 (which is an EQ-4). It's very much the same as the EQ-6, just a little lighter duty.

I'd say that even the C8 is too much telescope for the CG-5. The advanced series scopes look like decent GoTo values, but they will probably do nothing more than frustrate intermediate-advanced observers. If this is a first or second scope and you're serious about the hobby you'll probably grow out of quickly.

Have you considered the NexStar 925 as a somewhat more expensive but far superior alternative? Overall it will cost more than the EQ-6 + 925, but about the same as or less than the EQ-6 + 925 + current aftermarket GoTo solution.