Old Swedish dishes

[RimaNTSS]

HI All!
Last weekend I was going to pick-up one dish from local second-hand webpage. Went to see it, but found out that man is ready to get rid of more dishes. So I took 2 x "SMW OA 1400" and 2 x "SMW OA 1600".
I do not think you have them over the pond, so, just FYI
Nice dishes, very durable, have no mesh inside.

 

[KE4EST]

Nice Find Rim!!!

 

[RimaNTSS]

And this is actually quiet strange antenna. It is offset, but has only 13* offset angle and LNB is still located between antenna and satellite. It has opening angle about 112*, which means that usual universal converter will not illuminate antenna properly. Better is to use original feedhorn (which I have) or LNB from PFA, those usually have illumination angle about 120*.

 

[TRG]

I like the way the "wide oval" dish skews the whole dish. That one might work well for a multiple LNB setup.

 

[RimaNTSS]

I like the way the "wide oval" dish skews the whole dish. That one might work well for a multiple LNB setup.

This is toroidal dish (I believe) and it should receive (according to datasheet) in range of 26* with efficiency of 1m dish.

 

[RimaNTSS]

Hi! Installed one of the toroidal dishes. 23,5*E in the middle and 0,8*W on the edge. Reception on all LNBs more or less like reception on separate 1m dishes. I am still on testings, so do not have lots of useful info.

 

[FaT Air]

It's a mini TORUS antenna. http://www.global-cm.net/antennas/multifeed.html
http://www.gdsatcom.com/Antennas/Data_Sheets/655-0037C_7M_Torus.pdf

 

[RimaNTSS]

Made some LNB-holders, but seems that not enough of them. I also run out of 40mm pipe-clamps. all satellites from 45*E till 0,8*W are receivable with good reserve of signal. 12 LNBs are easy to fit.

 

[RimaNTSS]

Made additional LNB holders today to fill empty places in the row.

 

[spongella]

Very nice metalsmithing and interesting pictures of your adopted dish. That is one odd looking dish.

 

[RimaNTSS]

While I am on the good mood decided to make some details (INOX of course) and replace by them original rusty stuff.

 

[Titanium]

You must be retired!

You have so much free time to "play" with a great hobby!

 

[RimaNTSS]

You must be retired!

I wish I was, but it is still long way to go. Just a vocation, that is why. So, worked little bit more on replacing old rusty parts by custom-made out of INOX.

 

[RimaNTSS]

Do not have enough pipe-clamps ATM, when I have them will install 13 LNBs with Eastern one 45*E and most Western one 4*W. Also found out that antenna's surface washing does not give much, but if I rub surface by rubber eraser (expropriated one from kid) then surface becomes nicer (circled red). Need more erasers to finish all. I more and more like this antenna.

 

[RimaNTSS]

Installed all LNBs, now waiting for good weather conditions to do some scans.

 

[a33]

Interesting and quite beautiful setup!

What I'm curious about now, is the best pointage of the LNB's.

I can see that you have them now more or less parallel to each other, all pointing at individual spots on the dish.
I would expect (but I may be wrong), that with the LNBs in a straight line (or better: in a straight plane), as you have them, best results would be achieved by pointing at the center of the dish (that is: the boresight-point at the center of the dish, the G-spot, of which you know all about ).
And with a (doubly) curved multifeed-holder, as in the link in post #7 above, that best results are achieved with outward pointage of the LNBs, as is seen in the picture there.

So I'm quite curious to your next tests with this dish, and to what seems to be the best pointage!

Greetz,
A33

 

[RimaNTSS]

Thanks a33 !
I've already removed antenna and the mast , but, before doing that took some picture from above . You can see that LNBs are not parallel to each other, and edgy LNBs are located at the same distance from dish as central LNBs. So, each LNB is looking to it's own, imaginary dish (I painted those dishes on another picture yellow and blue) . On the same picture I made solid green line, basically that suppose to be "G-line", which connects all individual G-points of each imaginary dish. But I did not check location of this G-line on real dish. Maybe next time, when I decide to install dish, I will make more precise measurements and tunings.

 

[a33]

Thanks a33 !
You can see that LNBs are not parallel to each other, and edgy LNBs are located at the same distance from dish as central LNBs. So, each LNB is looking to it's own, imaginary dish

So you do in fact use a "doubly curved" set-up:

And with a (doubly) curved multifeed-holder, as in the link in post #7 above, that best results are achieved with outward pointage of the LNBs, as is seen in the picture there.

Your first photos evidently fooled me .
Thanks for clearing this up!

Greetz,
A33

 

[Dansky]

Hello All,

Apologies for the thread necromancy but I was wondering if this 12-14 LNB setup ended up working properly or not. I have the same dish (with its original parts, luckily) and it is working great with its 26° setup, but I'd give it a shot to extend that if it's feasible.

 

[RimaNTSS]

Dansky According to the manual, dish, as you say, works at equivalent of 1m dish within 26*. If you go behind the 26* limits, of course, reception will decrease. Ku signals in Europe are very strong, so I do not see big problem to go some 10* west and 10* east. Setup 45*E-4*W worked for me pretty well.
Could you show some pictures of your dish? Interesting to see..... there are not so many such a dishes around.