Posts Made By: Thomas Bennett

Hi Mark,

This looks like a good goto scope for a beginner. There's an older Astromart ad (698249) for one that might still be available. Just go to the classified page and put this ad number into the search field in the lower right (you might have to scroll down to see it) and the ad should come right up.


Good Luck, Tom

Hi All,

There's a 60mm H-Alpha scope (B1200 - Pressure Tuner - Crayford Focuser) on its way that I'm planning to attach to a Celestron C5+ mount. This is single-arm fork mount driven by a small 9V battery with the arm on the left side looking from the back (eyepiece end). Could someone tell me if the pressure tuner cylinder is on the left or right side of the OTA? I've seen pictures where is appears on either side but some of the pictures may be mirror images. Maybe the focuser rotates allowing either configuration? I'm hoping the cylinder is on the right so it will work with the C5+ mount.

Thanks, Tom

Hi All,

My first attempt at using Sky Commander XP4 on a Dob resulted in limited success. At first everything appears to work as advertised but pointing errors got progressively worse with time. After reading the manual more closely, I think the Sidereal Clock has been turned "off" for use on an equatorial platform and that’s why my non-platform errors get worse with time.

The manual indicates that there should be setup screens as follows: (1) Scope Mount; (2) Hemisphere; (3) RA Direction; (4) Dec Direction; (5) RA Encoder Res; (6) Dec Encoder Res; (7) Fast Track ON/OFF; (8) Sidereal Clock; (9) RS232 Baud Rate; and (10) SiTech Mode. So screen 8 is the one that needs to be turned from “off” to “on”.

But my Sky Commander only seems to display screens 1 through 6 while scrolling using the up and down arrows. Screens 7 through 10 are nowhere to be found. Does anyone know how to access screens 7 through 10 on Sky Commander or could my unit be defective somehow?

Thanks, Tom

My long awaited APM 152ED OTA has arrived at the New Jersey port-of-entry - thanks Markus!

The Customs and Border Protection (CPB) snail-mailed me a form indicating the shipment has to go through a Formal Entry process before its released to the USPS for delivery to me in California. Does anyone know if I have to do anything at this point and how long it takes to get through Formal Entry? The form is ambiguous about this.

I ordered this OTA before OPT became the US dealer for this scope so I guess I'm considered the importer.

Thanks, Tom

Here's pictures of an 8-inch blank I acquired years ago that was claimed to be a quartz flat. Labels on the box suggest it's from the US Navy Norfolk Naval Shipyard. Does anyone know how to verify this is indeed a quartz flat and what it might be worth?

Thanks, Tom

I’m in the process of converting a Nexstar 11 GPS SCT to video with a Mallincam Jr Pro camera, MFR-5 reducer, Sony 9 inch DVP, and 35 AH battery mounted on a heavy-duty push-cart (see picture). The scope will remain alt-az mounted (no wedge) limiting integration time due to field rotation so the camera was purchased with the more sensitive EXview HAD sensor. The system is coming together nicely but I had a couple questions about what else is needed.

Is the stock SCT focuser adequate for video or is a dual-speed or motorized focuser necessary to achieve good focus?

I’m in mag-4 skies but might occasionally view from more light polluted areas - at what point is a LP filter necessary for video?

The system currently doesn't have a finderscope - only a Telrad. Is the Mallincam + MFR-5 displayed FOV adequate to achieve a 2-star alignment with the Telrad or is a finderscope needed?

Thanks, Tom

It's Wilson!

Hi Brenda - After identifying your astro gear, the Astromart classified tab has a search feature at the bottom of the page where you can find recent classified ads for the same equipment. This will give you an idea of the market value of the items you might want to sell. As Floyd and Walter suggest, you should be able to find some trustworthy and knowledgeable people locally or on Astromart that can help you ID the equipment. Good Luck - Tom

Hi Chuck,

I've got a Starbeam on my refractor and Telrad on my dob. The SB is much lighter than the TR since the TR uses 2-AA batteries while the SB uses a light-weight button battery. The SB is nicer looking but functionally, the TR is more useful. Aligning the TR takes me just a few seconds - the SB can take a few minutes. The location of the dot projected by the SB is quite sensitive to eye position and I have some difficulty making sure my eye is always at the same location. I usually end up using a low power eyepiece to center the target before moving to higher power. The TR has a nice bulls-eye pattern and its projection is much less sensitive to eye position. With the TR, I can easily get within the field of higher power eyepieces in one step so I find the TR more practical. If a fancier, more compact TR were available, I'd replace the SB without hesitation.

Good luck - Tom

The one I looked through a couple years ago showed sharper planetary images than a nearby C14. Masking the Coulter down to 5" improved its planetary performance somewhat. This indicates that the total wavefront error on the Coulter was significant and masking down reduced this by finding a good spot on the mirror. My modern 16" dob was noticably sharper than the Coulter. The 16" performs better at full aperature than when masked down. This indicates good wavefront correction over its entire surface.