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Boller & Chivens retirement

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#26 Kokatha man

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Posted 31 March 2021 - 03:30 AM

I did replace the diode and it restored everything to normal operation.

It's interesting how some of us learned electronics, soldering, etc. I use it so rarely.

I think back and it didn't really have any practical application back then, just hobby stuff

shortwave radio, the transistor was pretty cool, no more 67-1/2 volt batteries.

 

Robert

I presume we're talking about the electronics on this old scope - sorry, but I cannot help myself after reading Robert's last post above...the "standards" were 45V, 67.5V & 90V batteries in the days of valve electronics...different voltages used for supplying the plate (anode) ("high tension") voltages of different valves/tubes in portable stuff...these batteries usually lasted a fair time because the current draw was very low; as a kid I pulled apart quite a few of these batteries laying around our house. The filaments for the cathodes were lower voltage & drew quite a bit more current & lasted much shorter between replacements...the higher voltage ones could really bite if you stuck your tongue across the terminals! smile.gif



#27 clamchip

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Posted 31 March 2021 - 09:36 AM

Yes telescope electronics, but also having a interest in and  learning of electronics in general when

we were kids, I don't think there were many of us.

I remember building many 'one tube' (one valve) radios, not many of my friends were interested.

I still buy the occasional swap meet multi band tube type radio and replace all the capacitors.

I've bought quite a few electronic telescopes and repaired these. It is not easy, some have micro

electronics and the components are too tiny for this old fossil.

 

Robert


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#28 Spectral Joe

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Posted 31 March 2021 - 11:16 AM

Perkin-Elmer.  The ones who paid $25M for the flawed Hubble mirror (under threat of gov't lawsuit) when the mission to fix it cost north of $100M.  Tell them they owe you as a tax-payer.

Perkin-Elmer lost a lot more than $25M, they were forced out of government contracting and sold the Danbury operation to Hughes, who sold it to Raytheon, who sold it to Amergint (whoever they are). Given the number of B&C telescopes out there, most still in use, I would try Amergint to see if they can provide some assistance. Having worked on a 36" B&C telescope, I'm familiar with the documentation provided to the customer. That documentation is somewhere in the astronomy department, contacting them is a good place to start.


Edited by Spectral Joe, 31 March 2021 - 11:17 AM.


#29 Jeff B1

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Posted 31 March 2021 - 12:36 PM

I had to work on the 24" Boller & Chivens at the USNO in DC and the drive electronics were like 1960's vintage.  Had to reach back in time to remember how those "room heaters" (tubes) worked.  Used it to observe Mars once or twice, but never liked it much.



#30 ccwemyss

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Posted 31 March 2021 - 04:19 PM

Just a reminder that an early post about this scope said the electronics and drive motors were redone by DFM, so no vacuum tubes. Most likely stepper motors with power transistor drivers. And, as a result, Amergint is unlikely to be willing or able to help much. DFM is still around, and other customers with B&C conversions by them might also be able to help. 

 

Chip W. 



#31 CHASLX200

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Posted 31 March 2021 - 06:10 PM

I had to work on the 24" Boller & Chivens at the USNO in DC and the drive electronics were like 1960's vintage.  Had to reach back in time to remember how those "room heaters" (tubes) worked.  Used it to observe Mars once or twice, but never liked it much.

Did it have a soft view?  I have yet to see a Cat really knock my socks off other than a very few SCT's that were way above the normal soft views.
 



#32 starman876

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Posted 31 March 2021 - 06:16 PM

Just a reminder that an early post about this scope said the electronics and drive motors were redone by DFM, so no vacuum tubes. Most likely stepper motors with power transistor drivers. And, as a result, Amergint is unlikely to be willing or able to help much. DFM is still around, and other customers with B&C conversions by them might also be able to help. 

 

Chip W. 

I have a large stash of old transistors.  Maybe I have what is needed.  Whoever needs help please PM me I will see if I can help out.  


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#33 bierbelly

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Posted 31 March 2021 - 07:00 PM

I presume we're talking about the electronics on this old scope - sorry, but I cannot help myself after reading Robert's last post above...the "standards" were 45V, 67.5V & 90V batteries in the days of valve electronics...different voltages used for supplying the plate (anode) ("high tension") voltages of different valves/tubes in portable stuff...these batteries usually lasted a fair time because the current draw was very low; as a kid I pulled apart quite a few of these batteries laying around our house. The filaments for the cathodes were lower voltage & drew quite a bit more current & lasted much shorter between replacements...the higher voltage ones could really bite if you stuck your tongue across the terminals! smile.gif


Great job Slick! (Harkening to A Christmas Story)

Edited by bierbelly, 31 March 2021 - 07:03 PM.


#34 tim53

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Posted 31 March 2021 - 07:21 PM

Did it have a soft view?  I have yet to see a Cat really knock my socks off other than a very few SCT's that were way above the normal soft views.
 

The B&C 16" is a cassegrain, not a cat.



#35 CHASLX200

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Posted 31 March 2021 - 07:24 PM

The B&C 16" is a cassegrain, not a cat.

I was asking about the 24".



#36 gnabgib

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Posted 31 March 2021 - 07:46 PM

Just a reminder that an early post about this scope said the electronics and drive motors were redone by DFM, so no vacuum tubes. Most likely stepper motors with power transistor drivers. And, as a result, Amergint is unlikely to be willing or able to help much. DFM is still around, and other customers with B&C conversions by them might also be able to help. 

 

Chip W. 

If the DFM "upgrade" was done more than 12 years ago the motors are brushed DC servo motors using Galil drivers and a Galil PC computer ISA card.  The software was proprietary to DFM.   I installed one of these control systems on Chabot Observatory's 36 inch cass named Nellie.  (Frank Melshiemer helped)   The system is very robust and has been working quite well for the past 15 years.  So I do not believe much of the original B&C drive except the worm gears remain.  I do hope that the DFM control system is still with the scope.

 

Kevin  
 



#37 starman876

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Posted 31 March 2021 - 07:52 PM

I was asking about the 24".

The 24" is alo a Cassegrain and not a SCT.


Edited by starman876, 31 March 2021 - 07:57 PM.


#38 Terra Nova

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Posted 31 March 2021 - 10:26 PM

Yes telescope electronics, but also having a interest in and  learning of electronics in general when

we were kids, I don't think there were many of us.

I remember building many 'one tube' (one valve) radios, not many of my friends were interested.

I still buy the occasional swap meet multi band tube type radio and replace all the capacitors.

I've bought quite a few electronic telescopes and repaired these. It is not easy, some have micro

electronics and the components are too tiny for this old fossil.

 

Robert

I built a Tesla Coil during the summer between 9th and 10th grade using an article in Popular Electronics. It was very cool. It operated at around 175,000 volts. I wound up donating it to the Physics teacher at the high school I went to a few years later. My brother was 10 years behind me and they were still using it for demonstrations when he was in school there.

 

Anyway, in the college where I went for my undergraduate education, we had an interim program between fall and spring semesters that ran four weeks, five days a week six hours a day. Everyone was required to take interim and you could only take one course. We had a course called Electronics for Scientists that I took one interim. It was great. Some theory but lots of practical training for maintaining instruments, cobbling things together, etc. We learned to use an oscilloscope, test circuits, put together simple boards, solder, etc.


Edited by Terra Nova, 31 March 2021 - 10:28 PM.

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#39 Jeff B1

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Posted 01 April 2021 - 05:56 AM

Did it have a soft view?  I have yet to see a Cat really knock my socks off other than a very few SCT's that were way above the normal soft views.
 

The 24" was a Classical Cass f/13. Yes, large obstruction.


Edited by Jeff B1, 01 April 2021 - 05:57 AM.


#40 CHASLX200

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Posted 01 April 2021 - 05:58 AM

The 24" was a Classical Cass f/13. Yes, large obstruction.

I have yet to ever see a Cass give a good image or at least the few i used at star parties.  A nice 12.5" at F/15 would be nice if it was sharp as a Zambuto Newt.



#41 Jeff B1

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Posted 01 April 2021 - 08:25 AM

I have yet to ever see a Cass give a good image or at least the few i used at star parties.  A nice 12.5" at F/15 would be nice if it was sharp as a Zambuto Newt.

Back in ancient times I made a 12.5” f/16 Classical Cass with a 3.5” secondary.  Images were fairly good but the contrast suffered a bit so I asked our local optician to make a smaller secondary and longer efl, so he polished me a 1.97” f/30 mirror and the images were very good.  Maybe using larger eyepieces helped.  Unfortunately a few years later I sent the primary off for a new coat and it was ruined so that scope was let go.

 

The UH24 was a 24" f/75 Boller & Chivens we used on Mauna Kea for photographing Mars and visually was very good.  I am sure if we had electronic cameras like are used today it would have produced excellent images, especially up on that huge volcano.


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#42 starman876

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Posted 01 April 2021 - 08:47 AM

Back in ancient times I made a 12.5” f/16 Classical Cass with a 3.5” secondary.  Images were fairly good but the contrast suffered a bit so I asked our local optician to make a smaller secondary and longer efl, so he polished me a 1.97” f/30 mirror and the images were very good.  Maybe using larger eyepieces helped.  Unfortunately a few years later I sent the primary off for a new coat and it was ruined so that scope was let go.

 

The UH24 was a 24" f/75 Boller & Chivens we used on Mauna Kea for photographing Mars and visually was very good.  I am sure if we had electronic cameras like are used today it would have produced excellent images, especially up on that huge volcano.

I had a 12" cassegrain I never should have let go of.    The detail on the planets was amazing.  However, that was in my early days of astronomy when I did not have enough good scopes yet to compare to the so so scopes to understand the good from the bad.  Later I realized what had slipped through my fingers. 


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#43 Jeff B1

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Posted 01 April 2021 - 10:09 AM

I had a 12" cassegrain I never should have let go of.    The detail on the planets was amazing.  However, that was in my early days of astronomy when I did not have enough good scopes yet to compare to the so so scopes to understand the good from the bad.  Later I realized what had slipped through my fingers. 

I now wish my 16" was a cass so my observing days would not have ended.  Sitting under a scope is restful laugh.gif


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#44 Terra Nova

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Posted 01 April 2021 - 10:58 AM

I had a 12" cassegrain I never should have let go of.    The detail on the planets was amazing.  However, that was in my early days of astronomy when I did not have enough good scopes yet to compare to the so so scopes to understand the good from the bad.  Later I realized what had slipped through my fingers. 

That seems to be the case! Big Cassegrains and convertible Newtonian/Cassegrains were much more common in those early days (1960s and early 70s) and seem to have gone by the wayside with the introduction of mass produced Celestron and Meade SCTs. Prior to that, anything Schmidt was just another very exotic telescope in amateur hands. I would love to see them come back. Seems they’re making a bit of a start with the various-branded GSO classic Casses. I just wish they were longer/slower. I’ve been on the fence about buying one since they were first introduced.



#45 tim53

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Posted 01 April 2021 - 11:08 AM

I now wish my 16" was a cass so my observing days would not have ended.  Sitting under a scope is restful laugh.gif

Sorry to trend off topic for this thread, but at least the B&C appears to be destined for preservation.

 

This is what you need:  https://alaskaapplie...delbrian-b-jpg/

 

Actually, *I* need it!  I just can't afford it.  I've been in contact with the owners and they would consider something like a long-term loan if I was a public outreach facility and would make it available for public viewing.  I'm not set up for that, unfortunately (plus I'm still working on Mars full-time).  So I'd have to buy it.  And they said they currently have something like $65K invested in it.  Last time I spoke with them, it was in storage awaiting a new home.

 

-Tim.


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#46 starman876

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Posted 01 April 2021 - 11:23 AM

I now wish my 16" was a cass so my observing days would not have ended.  Sitting under a scope is restful laugh.gif

that is what is so wonderful with any scope you can sit or stand behind to view.   Dobs are nice, but that boxy look is just not my style.  Plus as you get up in size now you need to stand on a ladder to view.  I like scopes that keep my feet on the ground and I do not need to pretend I am pushing around a wheelbarrow to put it where I want.    That is why I always loved cassegrains, a very nice design that kept the eyepiece in a convenient location.   My CFF cassegrain has  outstanding optics

 

ccf2.jpg


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#47 tim53

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Posted 01 April 2021 - 11:38 AM

My 12.5" f/23 Cassegrain has Ed Beck optics and is a very nice planetary imaging scope:

 

 

Attached Thumbnails

  • 12pt5_f23_Cass_on_EM-500.jpg

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#48 Jeff B1

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Posted 01 April 2021 - 02:33 PM

Sorry to trend off topic for this thread, but at least the B&C appears to be destined for preservation.

 

This is what you need:  https://alaskaapplie...delbrian-b-jpg/

 

Actually, *I* need it!  I just can't afford it.  I've been in contact with the owners and they would consider something like a long-term loan if I was a public outreach facility and would make it available for public viewing.  I'm not set up for that, unfortunately (plus I'm still working on Mars full-time).  So I'd have to buy it.  And they said they currently have something like $65K invested in it.  Last time I spoke with them, it was in storage awaiting a new home.

 

-Tim.

Tim, what a beauty.  The sit down position looks good.  As a retiree on fix income it is quite out of my budget cool.gif   Your cass is also a beauty.



#49 MassiveRedTelescope

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Posted 01 April 2021 - 03:35 PM

I visited the DFM site that includes info about the retrofit.  I didn't the pictured astro camera the other day when I went up to inspect the instrument.  The camera has a unique rotating shutter and was set up for 3.25 x 4.25 sheet film.  The exposure was set by varying the width of a v-slot cut into two discs.

 

The college is apparently revisiting their willingness to remove it from the building and I'm getting concerned.  I'll know more next week. 

 

I've located another former Berea student that had more to do with installation and maintenance than I did.   He's a Ph.D. engineer so between us we should be able to prepare the telescope for lifting (or remove parts prior to destruction).

 

(Trying to keep my spirits up about this situation)


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#50 MassiveRedTelescope

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Posted 01 April 2021 - 03:38 PM

Also, my friend tells me the B&C is f/18.




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