6 replies to this topic

[AVT-Astro]

Hi, there is a tube for sale locally that looks like a pretty good tube overall but I'm concerned about the lower Photocathode Sensitivity(1934). Do you guys' think that this is a good tube for general astronomy use? I have a variety of scopes from small APO to 24" f/3.2 dob and will be using it for all kinds of objects. 

 

2506 FOM
34.8 SNR
0.3 EBI
72 Res

PS 1934
NO Spots on spec sheet

Edited by AVT-Astro, 11 November 2024 - 03:37 PM.

[Jethro7]

Hello AVT- Astro,

You will enjoy using this device all the specs look good. The specs look alot like my first good tube that owned and it worked great. sense it is a local sale, you may be able to actually try it out before you buy it. 

 

HAPPY SKIES AND KEEP LOOKING UP Jethro

[WheezyGod]

Very solid tube. I’d go for it. Quite a scope you have there to use it in. I can only imagine the views you’ll have that I’ll be incredibly jealous of.

[sixela]

Hi, there is a tube for sale locally that looks like a pretty good tube overall but I'm concerned about the lower Photocathode Sensitivity(1934). Do you guys' think that this is a good tube for general astronomy use? I have a variety of scopes from small APO to 24" f/3.2 dob and will be using it for all kinds of objects. 

 

2506 FOM
34.8 SNR
0.3 EBI
72 Res

PS 1934
NO Spots on spec sheet

Almost my PVS 14’s specs. Solid tube.

Edited by sixela, 12 November 2024 - 08:09 AM.

[AVT-Astro]

Thanks for the reply's guys, I appreciate it! So, I did want to ask for those that maybe have gone this route before would a 3000+ FOM / 40+ STN ratio / .1 EBI tube be significantly better? In other words, would I fairly easily see some real difference when using them side-by-side? 

[chemisted]

Thanks for the reply's guys, I appreciate it! So, I did want to ask for those that maybe have gone this route before would a 3000+ FOM / 40+ STN ratio / .1 EBI tube be significantly better? In other words, would I fairly easily see some real difference when using them side-by-side? 

Sixela followed up the PVS-14 he has mentioned with a tube quite like this. You could PM him with your question.

Edited by chemisted, 12 November 2024 - 01:55 PM.

[WheezyGod]

Thanks for the reply's guys, I appreciate it! So, I did want to ask for those that maybe have gone this route before would a 3000+ FOM / 40+ STN ratio / .1 EBI tube be significantly better? In other words, would I fairly easily see some real difference when using them side-by-side?

Gavster is another who’s tried many different tubes. I’d reach out to him as well. He’s done a lot of comparisons that he’s posted online. Although SNR is hard to compare through photos if someone is using any averaging/stacking software.

I wouldn’t focus on the FOM by the way. Anything with a Res of 64 has been found to show no differences vs. a 72 or 81. The SNR is definitely important, but at a certain point any additional improvement starts to become very minor. On the other hand, smaller differences in EBI can have a larger impact unless you live in the northern parts (eg. New England) of the US.

Now if you want to maximize your chances of getting an extremely good tube, then I would call each of the major NV vendors (Apollo, Steele, Custom NV, TNVC, etc) and tell them you’re looking for something clean with a high SNR and very low EBI. If 2-3 of them happen to be getting new tubes in 1-2 weeks you could get something like a 40 SNR 0.2 EBI tube if you’re lucky. I wouldn’t wait any longer than this though for something that probably is only a minor difference if I had to guess.