3.7m Prime Focus Prodelin project: any ideas?

[Channel Hopper]

Ah, just checked and I only have the formula and drawings for the offset (Gregorian) antenna here, specifically the 1388 design. Somewhere however is another file with the convex notes and I'll have a chance to look further early next week.

 

[solly]

I prefer to use feed invacom only for test
as soon also for me serch more 0.3 to 0.33

 

[RimaNTSS]

Formula and drawing of the sub is one thing, but real challenge will start when you try to fabricate one. What kind of machine can do that?! As far as I know all subs for dual-reflection antennas (offset and prime-focus) are made of casted aluminum. I was exploring possibilities to fabricate the sub, and then found one company in Sweden which could print it in metal on 3D printer. They asked something about 300-500 EUR for the job. So, I said to me - NO, NO, NO.

 

[mar-val]

I made the Cassegrain. Asked few firms with CNC machines. They make it with cnc lathe or milling machine, by small step 0,03 or 0,01 mm. But it is still very expensive.

Another thing, I probably made bad calculation, or who knows, I dont have suitable feedhorn for that. Results were 10-15 perc. worse than Invacom feedhorn.

So I have nice aluminium mushroom decoration, maybe I will try again sometimes.

 

[Channel Hopper]

Whilst the first reflector is always going to be hand made, or machined, once the matched efficiency has been proven, this can be used as a former for cheaper production.

The cassegrain/gregorian design will have a narrower aperture feed than the single reflector, Prodelin offsets change from 51 to 39 degrees, equating to a change of f/d from 0.6 to 0.8

 

[pitussat]

I think it would be better to discuss the ways of installing the feed after seeing some pictures of the antenna, feedarms and feed itself. Installing of subreflector to big dish (and 3m is big enough) is good idea. The only question here would be where to get the SUB! Fabricate it is not an option, at leas not feasible one.

Since i work in telecommunication company.........i HAVE feedhorn from a 7/11GHz system ,3m cassegrain , and i could use the subreflector..

 

[RimaNTSS]

i HAVE feedhorn from a 7/11GHz system ,3m cassegrain , and i could use the subreflector..

Great! Then it is time to start to show some pictures We all like pictures!

 

[samoloko]

I would like to try cassegrain reflector but don't know which one can make such detail
although prime focus antenna Is 1.8 m I think It will benefit as It Is 0.32 f/d
If there are volunteers we can purchase machining detail with group buy to lower cost

 

[pitussat]

Here's some photos, but feed was covered by plastic bag.......
I have to make some better(photos) and focused on feedhorn

 

[Lazarus]

Fabulous!

 

[pitussat]

Here's PRODELIN 3m old version, the same of NELSON'S project,same panels, but with original polarmount and backframe

 

[Channel Hopper]

Here's some photos, but feed was covered by plastic bag.......
I have to make some better(photos) and focused on feedhorn

A very nice mount on the lower dish. Can you put up some more detailed pictures ?

 

[pitussat]

another couple of photos

 

[pitussat]

other photos, these are of feedhorns i have ex-work,

 

[moonbase]

The O/P has a job vacancy advertised on another forum to assist him with locating and viewing satellite feeds. He says compensation will be generous, subject to conditions.

 

[3virgul14]

The O/P has a job vacancy advertised on another forum to assist him with locating and viewing satellite feeds. He says compensation will be generous, subject to conditions.

Are you interested Moonbase?

 

[moonbase]

Are you interested Moonbase?

No, its not a project that I could allocate the time to.
However, I think that you might get plenty replies to your advert.

 

[3virgul14]

Dear Sat enthusiastics, have some exciting news.

I got the Prodelin working, after some custom steel and iron parts added to the pole, installed a second motor for vertical movement about 15 cm `s up and down, so little problems at the arc can be corrected.

Signal levels boosted at least 4-5db per satellite, now can get signals that I could never before.

Pictures and details will follow soon ;)

 

[3virgul14]

Ok here is the custom extension and the actuator.

https://imgur.com/a/nJGNMdV

 

[Channel Hopper]

You have been busy.

What have they started building next door ?