610 replies to this topic

[highfnum]

build 

[clamchip]

That would be neat a 2 inch f25.

My old Swift model 838 50mm had something I've never been able to produce in any other scope.

It was the airy disk, it was spherical, 3 dimensional. I don't remember the details, power I observed

this phenomenon, or if the star was slightly de-focused. If I remember correctly I'm pretty sure it was

at high power in-focus. I miss it that's for sure.

 

Robert

[highfnum]

swift 838  is a classic with a good rep

as far as i know it is f14 

which is a bit faster

 

my edmund 2 puts up a nice airy disk

with a ball in center i know what u mean

[highfnum]

ok  i dusted off my trusty time machine 

went back to 1973

picked up edmund lens 30-202  1.6 inch lens

with instructions 

 

so i will build that 1.6 inch scope  that i thought about so long ago

 

 

 

[highfnum]

the  orig pack 

[Terra Nova]

Keep us posted on your progress. It’s an interesting project. I thought about building one of those Wayback in the early to mid-60s. Never did though so I’ll be interested in hearing about yours.

[highfnum]

the goods

 

[highfnum]

well Terra

i built it

i tried to use black like edmund orig

same 30202 lens

followed their baffle instructions

 

 

but i used 1.25 focuser(MEADE)

 

[Bomber Bob]

Love It -- what a great project!

[highfnum]

its a small lens

although not my smallest 

got 25mm dollond 1790

30mm baby mak lomo

 

 

 

3inch edmund

 

is like Hubble in comparison 

will try star test tonight 

[Terra Nova]

well Terra

i built it

i tried to use black like edmund orig

same 30202 lens

followed their baffle instructions

 

 

but i used 1.25 focuser(MEADE)

ed42mine.jpg

That is so cool!  

[clamchip]

This might be worth investigating.

On the surface it appears to be a PDF of 'All About Telescopes',

https://www.scribd.c...bout-Telescopes

 

Robert

[highfnum]

tested 1.6  Edmund lens

 

not nearly as good as 2 inch or 3 or 4

 

one of lenses has  roughness on surface 

 

ok at low power but  below 10mm eyepiece 

image soft 

 

plus what a difference in brightness from 1.6 to 2

image is dimmer 

 

on the good side you can see inner part of m42

and trapezium 

it functions 

my decision 50 years ago to buy  2 inch lens

was a good idea 

[Terra Nova]

tested 1.6  Edmund lens

 

not nearly as good as 2 inch or 3 or 4

 

one of lenses has  roughness on surface 

 

ok at low power but  below 10mm eyepiece 

image soft 

 

plus what a difference in brightness from 1.6 to 2

image is dimmer 

 

on the good side you can see inner part of m42

and trapezium 

it functions 

my decision 50 years ago to buy  2 inch lens

was a good idea 

It was their lowest end refractor. I guess your experiment bears that out.

[highfnum]

yea i guess there is a limit on what a 12 dollar lens will do

i was hoping to do a shootout  1.6 vs  4 inch edmund and then 6 inch jeager

but i dont see the point 

 

but it is a true air spaced achro with tabs 

works pretty well with  28mm rke

like i said dont push and it will  obey

push to hard and it will balk

 

 

[highfnum]

it so cute

so small 2 inch is larger

 

[highfnum]

scope cost me 28 dollars in total to build

its foggy rain today

image with hand hold s8

 

[highfnum]

ok so i now got 4 edmunds - 1.6 inch (lens),   2 inch (lens) ,  3 inch 60's scope,  4 inch 60'scope

 

here are four star ronch test

 

1) notes 

1) 1.6 worse  (has rough optic ) kinda like and edmund version of criterion dx8 (actually worse than dx8)

2)  rest have pretty good results 

3) notice 3 and 4 inch show some CA even though they are F15 they are still great performers ill ask Bomber Bob to chime his opinion on those

4) notice small F25 lens (1.6,  2 )  do not show color  similar to apo ronchi - 2 inch works great

 

1.6

2.0

3.0

4.0

 

 

 

 

 

 

 

 

[highfnum]

for reference 80mm triplet apo -  astrotec

ronchi

 

 

[Vitez]

Thought that this group may like to see my rare Edmund 12.5" f/6 Newtonian mounted on my homemade GEM.

 

It was never in a Edmund catalog (to my knowledge) and the only other one I ever saw was on the Barrington, NJ showroom floor on the central stage mounted on a very nice a horseshoe based fork mount with an advanced positioning system and joystick control. In 1985 it was selling for $6,995!

 

I built my OTA exclusively from parts found in the Edmund Scientific Surplus Room, many of which should look familiar. This beast has cast aluminum end rings and a full thickness 12.5" mirror. The OTA weighs 82 pounds and the images are beautiful.

 

I've just added a Byers Clock Drive and will be taking more pictures if anyone is interested. I apologize tor the picture quality. It was taken on my phone and did not come out clear. 

 

This was my Haley's Comet project and took almost 2 years to build. 

 

Vitez

Attached Thumbnails

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Edited by Vitez, 28 February 2021 - 08:58 PM.

[clamchip]

Wow! rare indeed!

Incredible!

I'm too old for this kind of excitement,  I have a full time nurse at least I think I do...

Nurse Mendy, when she's not completely submerged  in my library !

 

[Eric P]

Here is the Edmund Astroscan (well pre-Astroscan) manual in case anyone needs a copy:

 

 

http://pieninck.com/...escope_2001.pdf

[mattyfatz]

^^^^^ thanks!

[jjbird]

Thought that this group may like to see my rare Edmund 12.5" f/6 Newtonian mounted on my homemade GEM.

 

It was never in a Edmund catalog (to my knowledge) and the only other one I ever saw was on the Barrington, NJ showroom floor on the central stage mounted on a very nice a horseshoe based fork mount with an advanced positioning system and joystick control. In 1985 it was selling for $6,995!

 

I built my OTA exclusively from parts found in the Edmund Scientific Surplus Room, many of which should look familiar. This beast has cast aluminum end rings and a full thickness 12.5" mirror. The OTA weighs 82 pounds and the images are beautiful.

 

I've just added a Byers Clock Drive and will be taking more pictures if anyone is interested. I apologize tor the picture quality. It was taken on my phone and did not come out clear. 

 

This was my Haley's Comet project and took almost 2 years to build. 

 

Vitez

Vitez,

 

That is a very nice looking Edmund Scientific 12.5” f6 reflector. I like the way you’ve mounted it equatorially.

 

A few years ago,  I was able to purchase the one that was displayed in the Barrington, NJ showroom, including the massive Astro Works fork mount. Transporting it from New Jersey to Wisconsin was nerve-wracking, but it endured the trip safely. Of course, I’ve treated it with kid gloves. 
 

Now I find out that the OTA has a twin!

 

Julio

[Vitez]

Hi Julio,

 

Thank you for the complement. Building a GEM for it was no simple task and now I have a Byers Drive mounted. I have always wondered what happened to that scope!

 

I was offered your scope for $3,000 in 1985 off the showroom floor. Putting that into perspective it would have been equivalent to a decent used car and my kids were only 6 and 3 at the time and we just purchased our first new car and were living paycheck-to-paycheck.

 

Out of curiosity, could you tell me how much you paid for it and send me some pictures? I have described the scope on the fork mount many times and get blank stares from people. Some "Edmundites" even question if Edmund ever made such a scope. Also, if you have any of the original paperwork I would love to have a copy. billvitez96@gmail.com.

 

It might interest you to know that it still cost me $870 in parts for the OTA alone ($459 for the Primary and Secondary, not surplus, and $100 for the Phenolic Tube). I saved over $400 in the cost of the end rings and hardware found in Edmund's Surplus Room. Total cost of parts without the Surplus bargains would have been $1,420 for the OTA.

 

I have a set of Novak tube counterweights (opposite the focuser and finder) to balance the OTA on its axis which doesn't show in the picture. 

 

Does your scope require an extension tube to focus? Mine does even with the primary set as far back as possible. I believe that this was done primarily for adding an off-axis guider and/or astrophotography equipment to allow sufficient focal length post focuser. I also scooped up spare parts and even raised washer cups and black button caps for the screws (the latter purchased at regular prices because all Edmund scopes used these). Since I built mine from parts, I could assist you with any questions regarding restoration and approach. The trickiest item was the secondary holder suspended by the thin steel "ribbon". I made a centering device that allowed me to "collimate" the center shaft within the tube to remove at least one optical collimation obstacle. I also found the correct spray paint color for restoration of the beige colored hardware and to paint new hardware to match if you're interested (the tube weights I mentioned are painted such). 

 

I also used a unique approach to the mirror cell for mirror retention and anchoring the threaded rods on which the collimation knobs turn (I have extras of the long threaded hollow knobs threaded washer locks and ball bearing with holes). BTW, those ball bearings are mild steel and rust so you may want to protect them. When I had the mirror resilverized I was reacquainted with the mirror cell and its quirks (quirky but solid). 

 

Best Regards,

Bill (Vitez)