Search found 3199 matches

by Merlin66
Fri Jan 18, 2019 3:14 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: ZWO ASI 178 or 183 mono
Replies: 14
Views: 1678

Re: ZWO ASI 178 or 183 mono

Brian,
I assume you mean the ASI 174?
I've used it successfully at all wavelengths (CaH to Ha) but needed the tilter to suppress NR.

If you mean the ASI 183 - should be OK in white light but I think, based on the known issues, would suffer in CaK narrowband.
by Merlin66
Thu Jan 17, 2019 12:10 am
Forum: This is SolarChat !!
Topic: Old Coronado BF30
Replies: 22
Views: 849

Re: Old Coronado BF30

Could it be a standard filter thread??
May be a M50 x 0.75???
by Merlin66
Tue Jan 15, 2019 10:43 pm
Forum: This is SolarChat !!
Topic: 17092017-AR2680 and western limb
Replies: 12
Views: 530

Re: 17092017-AR2680 and western limb

Bart,
I said back in 2009, that the PST DS was a pain in the butt to tune, so much so I gave up.....
Following your success and finding more rusty pins to stick in my eye (!!) I'm going to revisit this option.
Certainly an interesting option.....
by Merlin66
Mon Jan 14, 2019 9:02 pm
Forum: This is SolarChat !!
Topic: 17092017-AR2680 and western limb
Replies: 12
Views: 530

Re: 17092017-AR2680 and western limb

Bart,
Just re-visiting the PST DS thread.....
Any updates on your set-up???
by Merlin66
Mon Jan 07, 2019 9:19 pm
Forum: Solar Astronomy Shop and Swap
Topic: Wanted: SM60 external etalon
Replies: 2
Views: 871

Re: Wanted: SM60 external etalon

I'm still looking for a Coronado SME60 with Tmax.
Can you help?????
Let me know.
Ken
by Merlin66
Mon Jan 07, 2019 9:17 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Available external DS etalons??
Replies: 6
Views: 268

Re: Available external DS etalons??

Pedro, Interesting comment..... I recently tested a defective SME90 and had major "issues" with the Richview tuning....it ended up going back to Meade (from Australia) twice before effectively being repaired. I tend to agree, the original Coronado DS filter (I use one on my ED80 set-up) is very good...
by Merlin66
Sat Jan 05, 2019 11:11 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Available external DS etalons??
Replies: 6
Views: 268

Available external DS etalons??

I can't seem to find any Meade/ Coronado external etalons in the US...
The SME-40, SME-60 and SME-90 are still listed in the UK
http://www.meadeuk.com/Coronado-Etalon-Units.html

Lunt do a 50mm/60mm and 100mm
Is that correct???
by Merlin66
Sat Jan 05, 2019 11:06 pm
Forum: Solar Scope Modifications
Topic: PST Etalon Adjustment
Replies: 15
Views: 414

Re: PST Etalon Adjustment

Hmmm
Another cost saving exercise?????
by Merlin66
Sat Jan 05, 2019 5:13 am
Forum: Solar Scope Modifications
Topic: PST Etalon Adjustment
Replies: 15
Views: 414

Re: PST Etalon Adjustment

Brian,
That's part of the concern....
I've ordered a pack of the replacement O rings - when they arrive I'll confirm fitment and offer them to any members in need.
by Merlin66
Sat Jan 05, 2019 2:16 am
Forum: Solar Scope Modifications
Topic: PST Etalon Adjustment
Replies: 15
Views: 414

Re: PST Etalon Adjustment

Brian,
I’ve just be advised that the newer PST (< five year old(?) with anodized aluminum gold tube) don’t appear to have these Orings...never stripped one so don’t know how they maintain the outer tuning ring.

Can anyone confirm this, photos?......
by Merlin66
Fri Jan 04, 2019 4:32 am
Forum: Solar Scope Modifications
Topic: PST Etalon Adjustment
Replies: 15
Views: 414

Re: PST Etalon Adjustment

Brian,
Just removed and measured the O rings...
They appear to be 47mm inside diameter x 1.7 diameter.
The retaining grooves seem to be 1.8mm wide x 1.45mm deep.

Hope this helps.
PST_Orings removed.JPG
PST_Orings removed.JPG (289.5 KiB) Viewed 278 times
[Edit] The nearest standard size seems to be 47.35mm inside x 1.78mm diameter.
by Merlin66
Fri Jan 04, 2019 3:27 am
Forum: Solar Scope Modifications
Topic: PST Etalon Adjustment
Replies: 15
Views: 414

Re: PST Etalon Adjustment

Brian,
Some images of the PST, rubber ring removed, tuning ring removed, O rings visible....
PST_rubber removed.JPG
PST_rubber removed.JPG (95.2 KiB) Viewed 282 times
PST_tuning ring screw removed.jpg
PST_tuning ring screw removed.jpg (265.51 KiB) Viewed 282 times
PST_tuning ring removed_Orings.jpg
PST_tuning ring removed_Orings.jpg (278.83 KiB) Viewed 282 times
Hope this helps...
by Merlin66
Fri Jan 04, 2019 2:00 am
Forum: Solar Scope Modifications
Topic: PST Etalon Adjustment
Replies: 15
Views: 414

Re: PST Etalon Adjustment

Brian,
Hmmm - were the O ring grooves visible....may be no O rings there!!!!
by Merlin66
Fri Jan 04, 2019 12:59 am
Forum: Solar Scope Modifications
Topic: PST Etalon Adjustment
Replies: 15
Views: 414

Re: PST Etalon Adjustment

Brian, -Remove the rubber knurled ring -Look for the small Philips head screw in the outer ring -Remove the screw -Slide the outer ring off the housing -Look at the outer surface of the housing - you'll see the two O rings NB make a note of the hole that the screw was sitting in (on the inner ring v...
by Merlin66
Thu Jan 03, 2019 10:07 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Altair Hypercam 183M Mono CMOS Camera with ROI
Replies: 12
Views: 1406

Re: Altair Hypercam 183M Mono CMOS Camera with ROI

Brian,
Flats on the ASI 183 didn’t work for me.....
I have no issues with the ASI 1600MM....
by Merlin66
Thu Jan 03, 2019 5:50 am
Forum: Solar Scope Modifications
Topic: PST Etalon with a Quark, Log & Results
Replies: 70
Views: 1604

Re: PST Etalon with a Quark, Log & Results

Marty,
Another factor would be the amount of off band; the further from the Ha CWL the more likely the chance to pick up the Continuum......
by Merlin66
Wed Jan 02, 2019 9:51 pm
Forum: Solar Scope Modifications
Topic: PST Etalon with a Quark, Log & Results
Replies: 70
Views: 1604

Re: PST Etalon with a Quark, Log & Results

Marty,
Yeah, you're probably correct....better seeing and better focus might show it more clearly....
Onwards and Upwards.
by Merlin66
Wed Jan 02, 2019 9:23 pm
Forum: Solar Scope Modifications
Topic: PST Etalon with a Quark, Log & Results
Replies: 70
Views: 1604

Re: PST Etalon with a Quark, Log & Results

I occasionally have the PST etalon assembly double stacked on the SM60/ED80 (which gives an f10 beam) and BF15.. The image below was taken on 31 Dec 2018 using an ES x3 extender (for the first time) and the ASI 174 (excuse the NR - forgot to add the T2 tilter!) I'd like to think that this combo effe...
by Merlin66
Wed Jan 02, 2019 4:47 am
Forum: Solar Scope Modifications
Topic: PST Etalon with a Quark, Log & Results
Replies: 70
Views: 1604

Re: PST Etalon with a Quark, Log & Results

George,
Fair comment.
It would depend how how “matched” the transmission curves are and how close they are in CWL.
by Merlin66
Wed Jan 02, 2019 12:46 am
Forum: Solar Scope Modifications
Topic: Calcium K blocking filter
Replies: 17
Views: 566

Re: Calcium K blocking filter

George,
To get the Baader blue filter as far as possible up the OTA I bought a series of M48 adaptor rings, 50,30,10mm and used them to push the Baader forward.
by Merlin66
Wed Jan 02, 2019 12:40 am
Forum: Solar Scope Modifications
Topic: PST Etalon with a Quark, Log & Results
Replies: 70
Views: 1604

Re: PST Etalon with a Quark, Log & Results

The PST etalon assembly is designed to accept an f10 input beam and when positioned at the correct -200mm presents a collimated beam to the etalon. One issue, which would impact on the performance would be the blocking filter bandwidth in the Quark. I recently tested a PST blocker and it was close t...
by Merlin66
Tue Jan 01, 2019 11:49 pm
Forum: Solar Scope Modifications
Topic: PST Etalon with a Quark, Log & Results
Replies: 70
Views: 1604

Re: PST Etalon with a Quark, Log & Results

Marty,
Yeah, that looks good for a PST.....
by Merlin66
Tue Jan 01, 2019 11:18 pm
Forum: Solar Scope Modifications
Topic: PST Etalon with a Quark, Log & Results
Replies: 70
Views: 1604

Re: PST Etalon with a Quark, Log & Results

Marty, I find there are PST etalons and there are GOOD PST etalons. It could be your etalon has a bandwidth <1A ( "Acceptable " to Coronado/ Meade) but wouldn't do much to suppress the "Foot" of the DS bandwidth. Just a thought. You could put the lenses back on the PST, set it at the -200mm inside f...
by Merlin66
Mon Dec 31, 2018 12:19 am
Forum: Solar Scope Modifications
Topic: PST Etalon Adjustment
Replies: 15
Views: 414

Re: PST Etalon Adjustment

Brian, The 1.5mm screw you see just registers the inner ring to the outer ring (with one holding the knurled rubber ring). It can be moved one hole CCW to "improve" the positioning of the red wing - which is always near the end of the travel of the rubber ring.... The sloppiness in the tuning ring i...
by Merlin66
Sat Dec 29, 2018 6:04 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Altair Hypercam 183M Mono CMOS Camera with ROI
Replies: 12
Views: 1406

Re: Altair Hypercam 183M Mono CMOS Camera with ROI

RKBetra, Don’t know the full reason for the problems with the ASI 183....but I do know that ZWO acknowledges there is a major problem using it for solar H alpha narrowband imaging. They gave me a full refund on the one I bought. Replaced it with an ASI 1600MM which has given me no problems. Very hig...