SMW OA 1600 dish

[RimaNTSS]

As I've got 2 of them and already like them a lot, decided that I will renovate them. So, another project, hopefully with happy end.
I think this is very interesting and seldom antenna. Unfortunately they do not produce SMW 1600 anymore.
Will star from posting some pictures and link to it's technical datasheet.
From time to time, when/if I have some progress will continue. That can take some time.

 

[Lazarus]

Looks fantastic.

 

[RimaNTSS]

Looks fantastic.

Agree with you, bout this is not picture of mine dish :mad:
Mine look not so fancy and some metal parts are missing

 

[Lazarus]

Looks errm, interesting ............... !

 

[wod]

I think they made an even bigger 1.8m version with each offset lnb seeing an area equivalent to 1.1m dish.

Read it somewhere but forgotten.

Are the dishes complete or will you need to make some parts?

 

[Archived-1]

Interesting dish Rimants, some information about this dish here if needed .

http://translate.google.co.uk/translate?hl=en&sl=sk&u=http://www.dxsatcs.com/node/326&prev=search

 

[RimaNTSS]

I am not so great drawer... tried to show in different colors principle how this antenna works. Red frame- working area of the dish, I measured it as 1650 x 1080 mm (perhaps need to measure it more carefully at later time). Green dotted lines - vertical and horizontal axis. Somewhere on the green line all LNB's should be pointed (remembering that LNB should be pointed not at very center of the offset dish but lower). Blue oval- working area of the central LNB. Yellow oval- working area of the most left side LNB. I think those virtual working areas (blue, yellow .... etc) have dimensions like 105 x 108 mm (will confirm it later). Agree? Disagree?

 

[Archived-1]

I measured it as 1650 x 1080 mm

I am unsure if your talking size are working area Rimants, this is from the link I posted

 

[RimaNTSS]

I am unsure if your talking size are working area

As I've said- will measure it more carefully, not like last time- in half-dark garage. At this point of time precise dimensions are not so important.

 

[RimaNTSS]

Mount is also interesting solution. It allows to lean whole dish depending on piece of arc (26*) you are looking for.

 

[Archived-1]

As I've said- will measure it more carefully, not like last time- in half-dark garage. At this point of time precise dimensions are not so important.

Ok sorry for trying to be helpful, the manufacture has probably got the sizes wrong anyhow, so you best double check

 

[RimaNTSS]

Speakings about virtual dishes (blue, yellow.... etc) I am breeding idea how to measure those areas. I mean, to measure vertical and horizontal sizes and depth of those virtual dishes. When we know 3 main sizes of the offset dish we easily can calculate offset angle (according to technical data it is 13*), opening angle (to know what would be best LNB to use, I suspect this dish has about 80* opening angle), focal distance and LNB's aiming points for each LNB.
And, to measure 3 main dimensions of virtual dishes I am going to use chewing gum or dust tape and some water. Bright idea, does not it?!

 

[RimaNTSS]

Ok sorry for trying to be helpful,

No sorrys here! Any ideas and advices are appreciated! I do not want monolog (mine) here

 

[Archived-1]

No sorrys here! Any ideas and advices are appreciated! I do not want monolog (mine) here

OK I will be on my way

 

[RimaNTSS]

Just found a paper on which I wrote down dimensions of dish. Measurements were (not working area) 1680 x 1110 mm. Great part on the edges can not be working area, as it ir round and can not reflect signal towards LNB. So, I made an assumption that about 15mm from each side should be excluded from working area. From horizontal 1680mm I extracted 30mm and got exactly 1650mm (1650mm is mentioned in datasheet).
But working area in vertical dimension can not be 1110mm, after extracting 30mm, it is only about 1080mm.
And depth of dish at it's center was about 97mm.

 

[RimaNTSS]

And speaking about feedarms (feedframe), I think it is too much metal in front of the dish. So, feedframe could be done in much easier way. Anyway, one of the dishes I got, missing that curved INOX square tube which hold all LNBs. Therefore something new should be designed and fabricated anyway, so, why do not do it even better than original?!

 

[Llew]

Specification of all SMW dishes -

 

[RimaNTSS]

Even if it is written in the datasheet that "The design is a combination of an offset parabolic and spherical dish", in reality it is TOROIDAL dish! It looks like cut-off from toroidal shape (painted it green).

Edit: Changed picture, more realistic now.

 

[RimaNTSS]

I think I was wrong last might - seems that antenna is cut of a shape made out of circle, but antenna should be made out of parabpola. How do you think, folks, how this figure should be called? Marked parabola red.
I also brought home square bended tube made of INOX, it is holding all LNBs in front of the dish. When it was new, 40cm ruler was visible, now digits could be barely seen only if you change viewing angle.
I would appreciate if lucky users of such antenna post detailed pictures of the original LNB-holders.

 

[RimaNTSS]

It is good antenna is not so big and can fit in my car, other-ways I would not be able to bring it today home and gave it good wash.
After bath, made some measurements (will be continued another day). Found out that real working area of the dish is not bigger than 1058mm x 1660mm. I also measured depth of the dish along vertical and horizontal axis (measurements of the upper part of the vertical axis are still missing, just forgot to do that) starting from the center of the dish and measured after each 100mm.