Something wrong with this PST?

[moriniboy]

Anyone notice what's wrong with this PST. Hope no one from here shelled out £300 for this.

[Merlin66]

Hmmmm

It would help if the etalon assembly was still fitted to the Gold tube!!!!!

Certainly a HAZARD to solar observing with it missing........

[Ricochet]

3 hours ago, moriniboy said:

Anyone notice what's wrong with this PST. Hope no one from here shelled out £300 for this.

It might be better if it is someone from here, so that there is a chance they see this and don't use it. Did the comments pick up the issue? Any chance that the buyer knows there is a problem with it? 

[newbie alert]

Can you explain what's wrong with it?

I see it was on a face book page

[Merlin66]

Between the end of the gold tube and the black box there should be an etalon assembly which makes the PST a H alpha scope.

without the etalon it's basically a useless small achromatic scope.

Very, very dangerous to use as a solar telescope.

 

[Ricochet]

This picture shows the parts it should have.

[Peter Drew]

22 minutes ago, newbie alert said:

Can you explain what's wrong with it?

I see it was on a face book page

The most important part of the assembly, the etalon which essentially separates the hydrogen-alpha line from the spectrum, is missing! This fits between the "gold" tube and the black body.

I accidently took one like this to Tenerife. I usually take a PST with me as I have to wait quite a while for the Sun to rise over my apartment before I can use my larger solar telescope so the PST can be used elsewhere in the meantime. I had hurriedly assembled it before flying out and had forgotten to screw in an etalon. Fortunately no harm was done as the PST doesn't work without it.  

[Ricochet]

2 minutes ago, Peter Drew said:

The most important part of the assembly, the etalon which essentially separates the hydrogen-alpha line from the spectrum, is missing! This fits between the "gold" tube and the black body.

I accidently took one like this to Tenerife. I usually take a PST with me as I have to wait quite a while for the Sun to rise over my apartment before I can use my larger solar telescope so the PST can be used elsewhere in the meantime. I had hurriedly assembled it before flying out and had forgotten to screw in an etalon. Fortunately no harm was done as the PST doesn't work without it.  

It doesn't work without it? That is good, I had assumed it would just pass all the light without the etalon. 

[Peter Drew]

The etalon itself doesn't attenuate the light very much, you can look through it easily, the subsequent ITF and blocking filter seem to have the most effect. 

[Stub Mandrel]

I guess the etalon is 'fine tuning' the Ha and the other filters get rid of the wideband white light, UV, IR etc..

Presumably this toe-rag has take the etalon for double stacking and is trying to make money back on the bits from an unsuspecting soul.

[Merlin66]

It should not have be advertised as a "PST " telescope.

Without the etalon the fine Ha detail - filaments, prominences etc. is lost.

(The etalon passes 1A every 10A across the spectrum = 1/10 transmission)