Ryachu

I am incredibly grateful for the fantastic response. I've been plagued with guilt for doing nothing with the lens after all the work my colleague put into it. He retired and moved away a long time ago so we've lost touch. Inspired by the resourcefulness and handiwork seen on here there is fresh wind in my sails. The plan is to knock together a test rig before committing to any major construction. I've made a "sledge" to clamp to the inner stile of an extension ladder. The cell holder is nearly done I just need to sort out the other end. My ED-80 can act as a temporary donor for the parts at the eyepiece end. I've lost the notes from all the maths we did so the air gap is going to be a guess. The three bits of paper are just to prevent the elements touching. Once again thanks for all the wisdom. I might take advantage of your kind offer David, I'm just up the road in Much Birch !

I've had this 6"/F15 achromat in the back of my shed for the past 30 years. It was made for me by a colleague who had made several large mirrors and fancied a go at a refractor. I bought the BK7/F2 blanks from Germany and meanwhile we spent weeks poring over the maths. The numbers were sent to Edinburgh Observatory and to our amazement a kind person there put it through their ray tracing software and confirmed the curves by return of post ! My friend spent the winter grinding and testing while I went skip diving. Once the lens was finished I presented him with a large piece of aluminium, he wearily fired up his Myford, and the resulting lens is in the photos. I don't have a clue what to do with it. Is there somewhere it can be tested ? What sort of (2.2m) tube would I need ? Will it fit on an EQ6 ? Will the lack of lens coatings mean disappointment ? Any advice would be gratefully received.

Hi Jim, the silver plate holds the numbered ring into the housing and the dimples on the edge engage in notches on the ring. It does not look adjustable to me but maybe some sort of lubrication would help.

Another day, another flat button cell. Grrrr ! Dismantled everything in sight to get an idea of how it works. Replaced the button cell with a short circuit made from a piece of brass and a washer. 2 x AA battery box available at any good tat bazaar. Cut a slot for the external feed. Disconnected the -V from the PCB and wired up the battery box in series. ... and wallah ! Oops, forgot about the rear mounting bolt, stern letter to R & D. Should the batteies go flat I can just swap them for the TV remote when nobody is looking. Simples !

I'm wondering now if just rounding off the ends of the bolts with a file would have the same effect. I agree with the bubble level being way out of whack, I guess it is not the highest paid job on the shop floor. Then again, if the polar axis is aligned does the mount need to be level ?

Powering my EQ6-R from a bench power supply and the value under Utility->Show Information->Power Voltage is always 0.6 Volts high. For example, with 12.0 Volts from the supply the handset indicates 12.6 Volts. I've checked this with a Fluke DVM across the range 11.0 - 16.0 Volts. Can anyone confirm their handset is the same ?

A few mods that might help with other mounts as well. Clutch bolts: To eliminate movement when tightening the RA or DEC clutch a 6.5mm hole was drilled in the end of each bolt and a 1/4" ball bearing added. This decouples the friction of the clutch pad from the screw tightening torque. Clamping of each axis is more positive and requires only light finger pressure. Finder Scope Mounting : A dimple was drilled where the retaining screw anchors the foot. This stops the scope dropping out on my toes if not tightened enough. 😬 Polar Scope Right Angle Viewer : An adapter was turned up in a lathe to fit a Canon Finder B ( £15 off eBay ). It was then superglued at a slight, but annoying angle.🫤 Worm Bearing Tool : Hacksaw cut across a piece of 22mm plumbing pipe and solder a cross piece to engage the slots on the retaining rings. Should last for a few adjustments. Polar Scope Reticule : The first ring on the polar scope screws on and sets the clearance for the circular slide rule. The second ring rides on the first and has an inscribed line. Slacken the grub screw ( ~ 1mm ) on the second ring and rotate so the line coincides with the "0" on the reticule "clock". This make it easy to swing the RA axis and get the "0" on the reticule at the top before aligning to the clock value given by the handset.

Please ignore the above. I powered up the mount and had a quick sniff with a DVM. It doesn't look like a voltage regulator with 12V on the "OUT" pin and 0V on the "IN" pin. It seems to be marked A49T which suggests an N-channel MOSFET in an SOT23 package.

Hi, Just had a look at the PCB in my EQ6-R Pro with the code MC015 Rev. E 2019.04 which looks very similar to yours. The component appears to be marked 49T which https://www.s-manuals.com/smd/49 suggests is a 4.9V low dropout regulator. Unfortunately there was a blob of flux at the left hand end and scratching that off has now removed all markings !