Interesting dish

[RimaNTSS]

Hi all! Found pictures of one old but very interesting (IMHO) satellite dish. It is only 75 cm, seems to be portable, made of plastic and..... Cassegrain type! Unfortunately they do not produce such a dishes anymore. And it is hard to even find more information about it. I doubt that somebody in USA had it, but would appreciate some discussion on this issue.

 

[polgyver]

made of plastic

Usually, plastic dishes have some reinforcing "ribs" - are you sure this dish is made of plastic?

 

[Cosmo Blatz]

I did not know Tupperware made satellite dishes.

 

[RimaNTSS]

are you sure this dish is made of plastic?

Till I get this dish I am not sure. But, just looking at that and knowing it's age (~20 years and no rust) I am pretty confident it is made of plastic. Have found one of them for sale in UK w w w.nibroadcast.co.uk/Fuba-foldaway-satellte-dish-with-flightcase-85cm-diamter-/prod_2475.html , it is written "lightweight". Perhaps only mount and hinges are made of metal, maybe INOX.
Speaking about plastic dish and strength ribs: I have 140cm offset and 160cm x 110cm toroidal dishes made of 5mm plastic, they have no strenghts ribs at all.

 

[spongella]

Very interesting looking, I see it has a handle on the back, perhaps for portable use?

 

[bobvick]

It must have some metal somewhere in it perhaps a mesh embedded or some metal mixed with the plastic. There has to be something conductive somewhere for the signal to bounce off and reflect back, otherwise it would go right through it.

 

[RimaNTSS]

For the signal to bounce they usually have mesh inside the plastic, I think that is the case also here. I wrote an e-mail to the company who had made/designed those antennas more than 20 years ago and they replied with pictures of flyers , in German though.

 

[RimaNTSS]

My new dish has arrived and I like it. Quality is superb. Dish was never used as it was always stayed inside the shop and later in the storage. So, this is old but new dish!
Special twin LNB is inside which, perhaps should be changed to modern LNB adopted to original feedhorn. Skew of LNB is changeable by using screwdriver. Also has manual which I scanned and put here. Yes, handle is for transportation purposes, when not in use it hides in the frame.

 

[RimaNTSS]

Friend of mine has adopted universal LNB to this dish and now it is working as it should. I will now make some statement, please correct me if I am wrong: This is only Offset Cassegrain dish ever made, produced and sold. I like it, and not so much about performance but cuz it is so unique.

 

[Cham]

Really cool dish. Interesting system for adjusting the skew... limited to 20 deg + or - but that works fine in most applications. Also keeps the LNB(F) out of the sun and heat, might last a bit longer without the extreme temperature extremes. Is it a standard or universal LO? Looks like the scaler is manufactured with the LNBF so would be difficult to update.
I think most TVRO cassegrain style RF reflector antennae are offset design? Difference here is that the feedpoint is behind the main reflector rather than below. Big commercial uplink antennae often have the source and TWA behind the dish, connected to wave-guide, connected to a feedhorn close to the secondary reflector at the prime focal point. This design comes in somewhere between the two usual configurations I suppose.

 

[RimaNTSS]

Really cool dish. Interesting system for adjusting the skew... limited to 20 deg + or - but that works fine in most applications. Also keeps the LNB(F) out of the sun and heat, might last a bit longer without the extreme temperature extremes. Is it a standard or universal LO? Looks like the scaler is manufactured with the LNBF so would be difficult to update.
I think most TVRO cassegrain style RF reflector antennae are offset design? Difference here is that the feedpoint is behind the main reflector rather than below. Big commercial uplink antennae often have the source and TWA behind the dish, connected to wave-guide, connected to a feedhorn close to the secondary reflector at the prime focal point. This design comes in somewhere between the two usual configurations I suppose.

Cham thanks for input. I think that such a nice dish deserves to be mounted on polar-mount, so skew will not be an issue. Originally there was Twin LNB with 10000 LO, but friend of mine adopted universal Quad to the feedhorn, so now it is up and running (original LNB is #1, but adopted one is #2) . All the Cassegrain antennas are prime-focus, but this (as I have mentioned before) is unique as it is offset design.

 

[Trust]

Cham , but friend of mine adopted universal Quad to the feedhorn, so now it is up and running

Must be someone with a lathe

 

[RimaNTSS]

Must be someone with a lathe

Not only lathe but also brain! Thanks Trust

 

[Trust]

Not only lathe but also brain! Thanks Trust

I think I know that guy .