can you identify that dish

[samoloko]

can you identify dish on

http://snimki.be/store/1/701407831999.jpg

got to be around 2m height

 

[william-1]

180cm Channel Master

 

[archive10]

180cm indeed, but not a channel Master, I'm afraid.
That's a Prodelin 3180 Ka-band antenna.
RimanTSS bought one a couple of months ago, also in Belgium, with exactly the same polar mount.
Check the "large dishes for sale" for a discussion of this.
Very nice antenna, there's also one for sale in Germany at the moment.
Be aware that it has an f/D of 0.8, so you will need a Prodelin feedhorn to get the best out of it.
(Standard integrated LNBs are designed for dishes with an f/D of 0.6)

 

[Channel Hopper]

I hope that concrete wall is the reinforced type.

Hmmmm

http://www.satelliteguys.us/xen/threads/new-prodelin-project.344643/

 

[archive10]

I hope that concrete wall is the reinforced type.

Was just about to comment on that - and amazingly, it's a 1.8 meter dish mounted on the front of a high-rise at what looks like 10th floor or so. Wonder how they got that through the landlord / council!

 

[cat010]

if its 10 floors up proberly looks like a 1m from the ground

 

[samoloko]

dish look like dish here which Is said to be channel master 1.8

http://forum.dxtv.de/wbb/thread.php?threadid=20730&hilight=SMR 1224

 

[samoloko]

well dish Is Northern Satellite Corp NSC 18-1 but question Is where can be found a spec for that
here found same feed like the one on the dish - anybody know what Is f/d

 

[RimaNTSS]

How could I miss this thread?! OK, I see, it was started at about X-Mas time when everybody is busy.
Yes, dish looks same as mine, I mean back pattern. Mount is little bit different. I have more or less same mount as that guy from dxtv.de who has named dish CM, put it on Jaeger and got it broken during storm.
I did see same dish on e-bay in Germany, asked seller about name, but he did not know.
What I know about this dish:
- it has 180 x 2015 mm working area (measured);
- It has 26,7* offset angle (calculated);
- it has 0,5 F/D ratio (measured/calculated);
- it seems to be good dish, as string test showed no problems.

Somewhere I have several LNBs with tall feedhorns (like samoloko showed in previous post). Perhaps, those feedhorns, properly attached to new LNBs, could match this antenna.

 

[samoloko]

Rima you got very good collection
from what I understand dish with long arms got high f/d
high f/d feed got to be a tall one
which formula did you use to calculate f/d of your dish
_http://www.warunasat.com/showthread.php?tid=2820

 

[RimaNTSS]

Nothing good in that collection: LNBs are very narrow-banded, feedhorns are very specific (hoverer they are heavy, have lots of INOX screws and rest could be scrapped as bronze metal). If you wish I can send you one set for experiments.
To calculate antenna's f/d you can use any formula or program, results will be more or less the same.
IMHO: f/d parameter of offset antenna is useless. Much better is to use opening angle, which is 88* for this particular antenna.
There is profile of antenna, where you can see all necessary data, including position of"Le Point G"
-Focal length- 924mm
- Depth 194mm
- Opening angle 88*
and others.

 

[peeter3000]

hello.
I have same question..for my antenna.
tnx.
size 170 x 155cm
View attachment 72072

 

[samoloko]

Rima
which Is application you attached
when you measure focal length did you measure distance from lnb clamp to dish by putting ruler parallel to clamp upper surface
I guess result got to be closer to the focal distance

 

[RimaNTSS]

when you measure focal length....

How can you measure length if two end-points have unknown position? One point somewhere in the air, not far from LNB clamp. Another point, again somewhere in the air or on surface of dish, where is location of focus of imaginary PFA (from which this offset is created).
So, therefore, to focal length of the offset antenna could only be calculated, for example by formula from warunasat.com you gave link couple of posts earlier.

 

[Channel Hopper]

- it has 0,5 F/D ratio (measured/calculated);

Are you absolutely certain ?

 

[RimaNTSS]

Are you absolutely certain ?

Pretty much yes. 0,5 F/D it was my approximation. If more precisely, it is 0,52.
Can it be different if antenna's working area dimensions are 2015 x 1800 mm (sharp), and depth in the deepest point about 195mm?
So, than, after using formula
Focal length = (D*D*D)/ 16*h*W
we get Focal length = (1800 * 1800 * 1800)/16*195*2015 = 928 mm.
and F/D= 928/1800 = 0,52

But, as I've said previously, F/D of the offset antenna does not tell me much. I more like to know that this antenna has 88* opening angle.

 

[samoloko]

NSC 18-1 dish I am talking about got the same feedhorn like the pictures I have attached which are from other usa owners and from what I see the opening angle of feedhorn Is much less than 80* which by my knowledge Is higher f/d than 0.5
@st1 guess Is that Is a Prodelin 3180 Ka band Rx/Tx but there Is no specific feed arm which those dishes got - the feed arm with mounting plate

 

[RimaNTSS]

Do you know how to measure illumination angle of the feedhorn? I don't! Can you explain how do you make conclusion that that feedhorn has (not opening) illumination angle much less than 80*?
This dish looks like Prodelin 3180, it has more or less same strength ribs pattern, but front of the dish, and, more importantly dimensions of working area are completely different. So, therefore, this can not be Prodelin 3180, but another antenna. Which one? I do not know!

 

[Channel Hopper]

The 3180 series antenna has the same elevation offset as the Ku band version 1194 antenna at 17.3/17.35 degrees offset, and it is logical to assume both share the same illumination characteristcs.

http://www.gdsatcom.com/vsat/Technical_Docs/assembly_manuals/4096-668.pdf

The rated feed for the 1194 antenna is classed as 0.8 f/d ratio, and uses the 39 degree feed variant, 4080-062 or equivalent modern upgrade.

 

[archive10]

Ok, I've been pondering this a bit.

I think it is indeed a Northern Satellite Corp model 18 1.
But I must confess I have never heard of these before.
It may be a copy or a derivative of the Prodelin 3180 (or the other way around - but I doubt it).

Looking at the ribbing in the back, it is clear that although the dish looks strikingly similar to the Prodelin 3180, it does differ in several details. e.g. uppermost inner horizontal rib is almost horizontal on the 3180, but clearly angled on the NSC. There are also an extra couple of vertical ribs in the top half on the 3180, which are not on the NSC. And the NSC seems to have plenty of extra attachment holes for screws in the back, whereas these are not present on the 3180.

Looking at the front, as RimaNTSS has pointed out several times, the dish in question (the NSC) looks clearly different from the 3180, which has a "edge" in the upper and lower portion.

See attached pictures taken from Prodelin's web page at _gdsatcom.com

In fact, the NSC looks like the front of a Channel Master type 180, but with a ribbing heavily inspired by the Prodelin 3180.
It could also be a licensed design, or an OEM version made for NSC by either CM/Andrew/ASC or Prodelin.

Sooo - it is not just a case of assuming it's a type 3180 derivate, and that is has an f/D nearer 0.8 than 0.6. My guess would be that it is actually either a CM180 copy, or a completely independent design, inspired by the Prodelin 3180 ribbing.
In either case, the feed arms are more likely to be correct for the design - the same feed arms has appeared on multiple dishes, including RimaNTSS's, and the one samoloko is considering.

But ... the big question: Is it any good?
Well, whatever the origin of the design, the shape should be good, and performing very close to other SCM-based 180 cm dishes. It makes not sense to make this large a dish with the SMC process, and waste the effort in making a bad manufacture.
In other words, it should be worthwhile as a 180cm dish. At least very close to CM180/Prodelin performance.

UNLESS, something exotic has happened to the mesh embedded in the plastic. I remember reading somewhere else on the forum that this may have happened very early on. But I have never heard about this again.