Hi Thinking about the thermal load on the ERF I decided to clean the Black paint of the front ring of the holder for the Collimating lens with the Baader 35nm behind it. And polish it up. When observing a prominence in the PST Mod sweetspot a lot of Sun is shining on the ring. At 6pm here with a bit...

Hi

Very nice.

Just what I could see in the M180. Despite seeing as a bit cloudy and windy in Derbyshire.

Andrew

Hi I think my attempts to calculate temperatures from a buildings formulae might have been flawed. Going back to my Physics past I tried Boltzmans Law. I did write a program to calculate the temperate of an exploding wire with current through it as we for some reason I forget were blowing bits of wi...

Hi

So when I tune the PST etalon and a reflection wobbles about does that imply there is something lose inside the housing or is it normal?

Andrew.

Hi

What is actually in the PST body?

And how does turning the ring tilt the PST?

What is the orange bit?

Andrew.

Hi

I have not got round to imaging yet.

I had one try some time ago with a little QYH and the PST but could not find focus.

When we get some clear skys I could have a try.

Andrew.

My pants are not on fire! Some temperature measurements on this and other telescopes: Santel M180 After developing a Stage2 PST Mod on the Vixen VMC110 I decided it was safe to try it in this telescope. I bought a cheap yellow laser pointed remote thermometer. It is defaulted to 0.95 emissivity surf...

Hi As most bits in a scope are alloy tube perhaps a bit of alloy sheet, with an air gap and then another bit of alloy for internal bits. Both anodised or painted black. The cooling effect is greater in free air to an enclosed space. You do not want extra radiation or convection off the open back. An...

Hi I mentioned Mark T used a KG3 for imaging as he feels the long IR affects the image. I also put a Beloptic on my original PST for visual and it seemed to help for me. My Beloptik KG3 on the eyepiece does reduce the thermometer reading out the back on the Maksutovs, but not on the refractor as BK7...

Hi The simple glass front ERFs do pass a lot of energy. I would always put a Baader 2" or 1.25" 35nm behind one of those. I have been taking readings on my Vixen VMC110 Mak, been using for 2 years. Santel M180 Mak and a 90mm triplet recently. I will write a report. Using the cheap laser pointed yell...

Hi In the Mak 180 I could see the prom in the last image similar to your last image. I could see two jets either side with filigrees in between. A couple of bright spots. I have done a temperature analysis which I will post. The Collimator/Baader 35nm are at 50C in the Mak. Secondary cooler than I e...

Hi

Nice image with the proms.

The bright one looked like a little horse for me in the Santel M180.

Andrew.

Hi

Thanks for the reminder.

Andrew.

Hi I referred to list on CN which I could not find a link to after a data disaster(My only one). But on holiday I found a link to data Christian V posted here earlier: Daystar Yellow Absorb 29% Transmit 71% Daystar Red Absorb 30% Transmit 60% Astronomic L Reflect?49% Transmit 51% I assume a dielectr...

Hi The cheap sets Bob sells are cosmetic defects for the H-alphas. The first set we had had one h-alpha bonded to the 40nm blocker but had large no of reflections so were returned. I am afraid I caused AstroRod time and money as we only found out later solid filters should be used near focus and bui...

Hi

Thanks for the advice.

AstroRod had the filter crack and he did not notice for a bit. Then stopped using it, my bad there.
He was using it in the same place you have your red filter.

Andrew

Yes a dielectric 35nm Baader filter is the best to have first. For visual I use a Beloptik KG3 with IR and UV coatings on the eyepiece for safety and catch the long IR the Baader passes. Could use it in front of a CCD as well. I think removing the long IR helps visually for me, 2" BeloptiK on front ...

Hi Merlin,

Pictures deleted.

The two h-alpha filters were dated as purchased. The background one is for information so date not relevant.
Showing Bobs 40nm blocker stops IR out to the limit of the scan. It does have a bit of blue leakage.

Andrew

Hi Merlin, Thanks for that. I was having a look around for absorption in mirror coatings. But they only specify reflectance. I assume some light is scatttered. Santel was a former Intes-Micro enployee who used their mirror sets, at least to start with it appears. Intes used LK7 for the mirror and LK...

Hi

Bobs ERF is supposed to block long IR.

Andrew.

Hi Merlin,

The equation I use is for free air so I could be a bit hotter?

Where did you get the 27% from please?

There was an article which stated 1/6 as I recall, will the skirts on a simple etalon give some extra trasmission. Its not critical for my post.

Thanks. Andrew.

Hi Radiation and heat status in the telescope. Version 2. Closed Tube unlike the Visac. Details about the 35nm from Merlin: I am ignoring the secondary obstruction. Its black and the front absorbs some heat though is clearly radiating more away at 24C over ambient. Half the secondary heat load? Prim...

Hi, I had the first good day when I have been at home for the year so far. Had the Vixen VMC110 F9.4 out with a PST stage 2 mod and one of my 0.15nm Omega H-alpha pair in a Celestron/Skywatcher Moon filter just losely held in as the Comb Blocker. Which looks like a production filter not a cosmetic s...

Hi The 8 returns were for some one trying seconds CAK filters I recall. Bob the owner of Omega Opticals reply was: This is new production of a single cavity FP etalon. It is only the narrow passband, that controls from 0.8 to 1.3 times the CWL. I have asked him a clarification question about it bein...

Hi A compact PST mod I did was to use a Vixen VMC110 F9.4 OTA. Got a cheap OTA only return on EBAY. Luckily moving the PST Collimator lens forward enabled me to just reach focus. My engineering friend used a cheap barlow body for the mod. Which is a nice fit with 'opticians tape' in the scopes back....