Merlin66

The latest upgrade of Cartes du Ceil (V4) is well worth persevering with. The additional catalogs further increase CdC capabilities.

Access EQMOD through Stellarium???

Marv, so far so good.... ASCOM and EQMOD are best thought of as “gateways” between your planetarium program and the SW mount. you haven’t mentioned your planetarium setup...Stellarium?? With stellarium scope?? I use EQMOD with Cartes du Ceil to control my NEQ6.

I purchased my 32mm TV back in the 1980’s and it’s still in regular use.........

I used the C8 Meade equivalent successfully on a HEQ5 mount for a while...... Having said that I moved to a NEQ6pro later (for a C9.25) and found that even more stable and easily capable of handling a C11. (Inow use a C11 with a spectroscope, four cameras and electronic finder on a NEQ6PRO- no issues, no drama.)

https://britastro.org/spectro2019 This should be of interest to all amateurs interested in spectroscopy. Both BASS Project and ISIS software will be covered.

Rusted, many years ago pre HIteech etc Shoestring were the only option..... the PC control of the focuser is very good and works well for me on everything from the ED80 through to the C11.

I used the Shoestring focuser motor adaptor for all my focuser motors ( I have five of them!!) works very well for me. I made up a 3mtr RJ10 cable to give more flexibility.

You need a spectroheliograph and some extra 1/4 wave filter elements to be able to determine the magnetic polarity.

For a Newtonian telescope on an EQ mount, rule of thumb is the observatory should be twice the focal length. Doesn’t apply obviously to SCT type scopes.

Astroe, yes, I have used the NEQ6 with an dual ED80 and 6” comet seeker. No issues, no drama.

Sorry, based on the discussions I assumed this may have been of assistance.

With 1/2/3 star alignment.... let’s assume your PA is as good as you can achieve. the start position is “Home” position - scope pointing towards the pole, counterweights down. if the slew to the first star is “off” then as per discussions above you have two options: 1. Unlock the axes and manually recentre the target star. 2. Use the handcontroller to re-Centre the target star. what’s the difference?? #1 the mount motors have been driven (energized) for a series of pulses the number of pulses in each axis based on the gear ratio and the calculated difference (RA and Dec) between the home position and the target star. Obviously if the home position is 100% correct and the gear ratio is 100% and the calculation model is 100% the target star will be exactly in the Centre of the FOV. It’s typically assumed any error is due to an error in the Home position setting. Moving the mount manually doesn’t add/ subtract any pulses. This then infers that the pulse count used to move the scope was correct; the next move to the second alignment star with then continue to use the original internal model (ie the gear ratio/ pulses per degree). If the second star is found central to the FOV, then it would probably confirm the packing position was indeed incorrect. If there’s still an issue with the second star, manual correction should not be used..... #2 making the first star correction using the handcontroller will add/ subtract motor pulses. This correction will then be used by the internal model to change the pulse per degree rate. The model will assume the initial Park position was 100% correct. If the second star is off Centre, using the handcontroller to correct will once again add/ subtract pulses and “ up date” the internal pulse/ degree rate...... It’s anticipated that these rate (pulses/ degree) changes will result in an improvement in subsequent GOTO accuracy. In a real world, a combination of both methods may be used. So much for theory....... I have a permanent well PA aligned mount in the observatory and use EQMod to Park and Unpark the mount (so there should be no error in Park position) and I still find the first alignment star is still repeatability “off” by a degree or so, always in the same direction. Using the manual/ handcontroller correction improves the immediate GOTO, but at start-up the next session still shows the same initial error. I honestly don’t know why........

If the ITF has failed then it SHOULD be covered by warranty and be replaced by Meade. you may find a problem.....the warranty documents say if the PST is opened, then you may void the warranty. Doesn’t make sense, as you have to removed the eyepiece holder to determine the failure of the ITF!!!! (Replacement ITF drop-in filters can be obtained from Maier Photonics, USA)

Paul, It’s most unusual for the final little red filter in the eyepiece tube to deteriorate. This is the blocking filter, a very narrowband red filter. The ITF is located at the bottom of the eyepiece tube section where it meets the black box. This can be difficult to examine due to the loctite used during assembly. I have never seen a blocking filter fail in my >ten years experience with PST’s but I have seen numerous ITF failures.

The Gaia is the latest detailed catalogue with millions, millions of stars. the CDC webpage gives all the necessary details.

A filter(Baader solar screen) fitted to the ST 80 would probably give you as good if not better results to a 50mm aperture with the Dobbie.

+1 for the Baader cool Herschel wedge.

Can’t help with the fitment of the OAG, but I would question why you think it necessary if you are going to use a SA100 grating? Normally the grating would be mounted in the 1.25” camera nosepiece. (Which camera do you intend to use?) With an EQ mount the non-guided tracking accuracy is probably good enough to get you started.

+1 for the heated doggy blanket. works very well.

As Robin has said, the reflection only affects the guide image. Only usually a problem with very bright stars.

Hmmmm That’s not what the telescope manufacturers have said in writing. Al Nagler published in Sky & Telescope that the TV Petzval instruments were 100% safe to use with the Herschel wedge. I also have the same response in writing from Williams Optics and Takahashi....... I think it’s a perpetuation of the urban myth......

No. All the manufacturers of Petzval type refractors have confirmed in writing that their instruments are 100% safe to use with the Herschel wedge.

Variable focal length primary = vacuum actuated thin plate mirror ????

OK. I use the Baader Cool Herschel wedge.