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Coronado SMN35 Equipment help

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#1 bob11746

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Posted 06 June 2020 - 12:57 PM

Hi All,

Now that I am retired, I can pull out my 20 year old Coronado SMN35.  It's in a few pieces, because back then I had trouble with the throughput and filters, and I was also doing some experimenting looking for a way to speed up temperature stabilization (manual etalon tilt).  The SMN35 was powered by 12V, but I cannot remember for the life of me if there was a special controller associated with it, something that would allow less than 12 volts to be applied.  I don't believe there was any type of external active temperature control, if anything, it was built in.  Being an early adopter at the time, I have one of the early serial numbers, one of the first handful produced.

 

Does anyone out there have one of the older models?  Can anyone help with the external power control?  Was it just a 12V cable?  Any help anyone can provide in explanation, pictures, etc.. would be most appreciated.

 

Thanks,

Bob


Edited by bob11746, 06 June 2020 - 01:00 PM.


#2 BYoesle

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Posted 06 June 2020 - 02:05 PM

Hi Bob,

 

The only information I have comes via Christian Viladrich, who recently acquired a simial era SMn35:

 

- The setting of the temperature is through a minute screw with no

graduation. This is not the best idea David Lunt had ...

 

- The heating is through a 10 watt resistance, which leads to a very
long time to reach thermal balance (about 45 min). I am playing now with
an extra 10 watt resistance to boost thermal balance.

 

- The BF2A is very difficult to tune properly. I still have to figure
out a way to do it.



#3 bob11746

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Posted 06 June 2020 - 03:19 PM

Hi Bob,

Thanks for the reply.  The 45 minutes was a major reason why I wanted to experiment with a mechanically tiltable etalon.  By the time I got setup, everybody was moving on to the next activity!  I also had major problems trying to see the Ha line, there was zero contrast.  I had provided my own red filter up front, and Mr. Lunt (Sr.) had attributed my problems to that.  I disagreed, the filter up front is a energy rejection filter, the contrast is provided by the etalon and the BF.  I also added some filters in between the etalon and the BF to remove the double reflection from the faces of the etalon and the BF.  Other than the 45 minute warm up, I got it working nicely.

 

Now twenty years later, it is time to fire it up again, get it to working status, and then I can play again.  I have a PST and that just doesn't do it.  I was spoiled with great views, I had a friend who had a double stacked 90mm on a 5 or 6" AP.  Absolutely spectacular.  I hope to get close to those old memories.

 

Bob




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