fredvanner

As relative novice about to start trying serious imaging with my EdgeHD 8: This accurate position must assume a fixed position of the mirror - which I assume will be at or near one or other extreme of the mirror focus adjustment range. I also assume some adjustment must be left for fine focus adjustment, which must be done with the mirror adjustment since there is nowhere to put another focuser in the fixed imaging optical train. Where should the mirror adjustment be when setting up this imaging configuration (with the flattener in place)? If I'm missing something, please explain what.

Could you borrow another SynScan, which could eliminate mount / cable problems (e.g. ask at your local astronomy club)? It sounds to me increasingly like a SynScan handset fault - I had a fault very similar to this a few months ago.

I bought the "Dual-Speed 2" Crayford Focuser for SCT Telescopes" (£134 from FLO) for our SkyMax 150. It has been excellent - fine focus adjustment with a Bahtinov mask and focus lock usually lasts all night.

This looks very similar to a problem I had with a SynScan controller (with an HEQ5-R mount) last year. My controller started to have intermittent failures with the "RA/Azimuth no response" error. It also became intermittently unresponsive to some button presses. Eventually, my supplier agreed that this was a controller fault, and sent me a replacement which has worked perfectly ever since. However, I'd check your supply voltage first - these controllers don't like low voltages.

If the SynScan handset is talking at all, you could try "utility function>show information>power voltage" to check your power. It needs to be about 12-14V. What exactly does it say when it powers on? (This can sometimes be diagnostic).

The AZ-GTi is really an Az-Alt mount, and does not easily support equatorial operation. Even on a wedge, it will be hard to polar align (I use my AZ-GTi for quick setup public outreach events, with a small refractor). The Star Adventurer, being a single (RA) axis mount, will also require a wedge (or equivalent tripod ball joint - but I'd go for the SA Pro wedge), but has the advantage of a built-in polarscope for alignment. This sort of lightweight configuration is fine for wide-field DSLR imaging (which is relatively undemanding of accurate alignment - particularly if you avoid very long exposures). However... ... if you are as lazy as me I would just hate to go back to the days without GoTo! You can plate-solve with any camera (the mount isn't relevant - unless you want to integrate plate solving with the mount goto function). I image using APT, and now regularly use the GoTo++ feature that does an iterative GoTo > Image > PlateSolve until the selected target is centred (but that is with a proper equatorial mount).

According to the manual: "The SynScan hand control divides the sky into 85 small zones, and users can calibrate the pointing error for each of these zones. The next time that the SynScan controller tries to locate an object in the calibrated zone (or a zone nearby), it will automatically apply the recorded calibration data to compensate the pointing error.". Does anyone know: If these areas are fixed, and if so where they are. How close is a "nearby zone". I calculate 85 zones implies about 20° x 20°, or about the average size of a constellation. I ask because I'd like to know how close a new Pointing Accuracy Enhancement fix will typically be before it overwrites a nearby fix.