Gemini 1.04

[Mamba]

I have rather stupidly put the Dec cable into the Gemini unit at the wrong angle and on powering up the mount immediately slewed in Dec at high slewing speed.
Today I have had time to examine things.
By changing the Dec and RA cables I can make the two motors slew, only one at a time, I have to change the cables over again to make the other axis slew. Both axis are high speed and uncontrollable. However it does mean that the motors are not damaged (cue Monty Python's Always look on the bright side)
It also means that I have almost certainly damaged the PCB and have been looking around for a replacement board (PCB 3050079-00 REV H) but it seems that the older Gemini 1 is no longer supported, no joy at Bintel but am waiting for a reply from Losmandy USA.
Do any of the members of this forum know of any supplier of the board or any repairer of these boards.
Hopefully
Dave Cooke

[blink138]

i think our member "was young once" (brendan) may be the person to ask, he tinkers a lot on the older g11 mounts
pat

[Mamba]

Thanks Pat,
Will try to get in touch with him, I've really gone and done it his time, I think the Funeral March would be a more appropriate piece of music.
Dave Cooke

[JA]

You could take a look at the PCB, post a photo (suggest both sides of PCB) and/or bring it to a general electronics tech. Maybe the fault is apparent, via inspection or basic test - a fried resistor, output stage transistor, capacitor...... sometimes leave their mark. Sometimes repairs are even possible without the circuit, although more difficult.

Good luck and Best
JA

[Muzzas]

I hate it when electrons are faster than me to rip the cords out
If it is a real mess you could go down this path.

http://www.iceinspace.com.au/forum/showthread.php?t=136452

[DavidH]

Or you could use this controller:
http://www.siderealtechnology.com/ which will work with your existing motors I believe, but will require software setup.

[wasyoungonce]

Spoke to David by PM...he's bringing it over when possible. Hopefully it'll be simple.

[wasyoungonce]

Ok Gemini is now working it was the U15 DEC PLD.

Unfortunately these have a habit of dying if you misalign the connectors when plugging. This can put motor drive onto the encoder or straight to the PLD...damaging it.

So folks please be careful when aligning these motor plugs on Gemini 1's. :sadeyes:

More testing to do but it's looking good.

[thebonz]

Good one!

[spiezzy]

love a happy ending well done
:thumbsup::thumbsup::thumbsup::thum bsup:

[Mamba]

Hey, Come on you guys, I was waiting to get it back before handing out the bouquets. But yes, it sounds as if Brendan has done a brilliant job and saved me a fortune. Will let you know when I attempt the first 'go-to'
A very happy Chappy.
Dave Cooke

[thebonz]

great that it will be working

[Mamba]

Urgently require help in composing a suitable reply to this absolutely unwarranted slur on the abilities of the Losmandy G 11 and it's owner, ancient or otherwise.
Something along the lines of venomous, vicious, malignant, rancorous, caustic and not very nice to boot.
Oh, and the Mewlon is still wonderful.
Best Wishes
Dave Cooke


QUOTE=thebonz;1299206]I hope it is fully functional and guides you in to target. Nothing like a fully functional mount,
Good luck
Bonz[/QUOTE]

[blink138]

haha well done brendan i am glad i remembered reading abot your g11 tinkerings!
pat

[wasyoungonce]

Ahhh plugging away...was trying to measure the PLD servo loop pulses between it and it's axes PIC controller.....damn...even on my 100mhz oscilloscope...can barely see them.

Gonna need a bigger scope!:lol:

Good to hear Dave...happy viewing!

[Mamba]

Just been out tonight to check out my repaired Gemini 1 care of Brendan. The moon was a bit overpowering but never have I been happier to see it slide into view as I was tonight.
Brendan has done a brilliant job and even provided a two and a half page report.
This is not the result of a guy with a Bunnings $20 multimeter on his kitchen table surrounded by breakfast residue!
Many thanks to Brendan
Dave Cooke