Unknown dish? - re-assembly - anyone recognise it

[nelson_b]

hi -
i,v been meaning to make this post for ages --
In febuary this year i bought a 1.8 prime focus dish and ground-stand - that had been taken apart and stored for a number of years --
after cleaning and rust treating and repainting the steel parts i re -assembled it .
It has no manufacturers name anywhere ? and i would like to know who it was made by ?
The whole thing is quite heavy duty as you can see from the pictures - especially the mount and ground stand ,the pole is 5 and a half inch diameter --
the feed and l.n.b in the pics is as i bought it --

i have since experimented with many different l.n.b. / feed arrangements
both k/u/ and C band - when i could find the time - but it is currently k/u - and aimed at 42 east and used to receive radyo Eksen on 11054 H 30000

here,s hoping someone can identify it

regards nelson.b.

 

[Channel Hopper]

The only 1.8 I know that looks anything like that is the Alcoa, but the backplate and ring assembly don't ring a bell.

 

[nelson_b]

The only 1.8 I know that looks anything like that is the Alcoa, but the backplate and ring assembly don't ring a bell.

thanks for the reply -- Channel Hopper -- i did hope you might have seen one of these before----
i bought it as -- a hobby/project -- as apart from a 90.cm uniden dish i,v not owned a prime focus before --- ( i enjoyed buiding and testing it )
judging by the heavily pitted rust that was on the mount and fixing ring -- which is made of very thick metal it must be pretty old --- over 20 years for sure !

i wondered if it might out perform my trusty 1.8 offset channel master that i,v owned for 10 years now -
but although it is very close -- the channel master still has the edge

cheers nelson.b.

 

[Channel Hopper]

The prime focus dish would normally be about 5% lower in efficiency, owing to the feed and feed arms being in line with the signal. In reality though there would often be a further 10% or so lost owing to the panel design over a one piece reflector.

The petalised system trades in overall gain for ease of manufacture, packaging and transportation, leading to a lower production cost.

 

[Satcom1]

channel hopper is right on regarding the petals and seams. I have seen some commercial dishes that have filler pieces for Ku. C band not so critical. You should also try to use a flat Ku scalar like the Invacom. SatelliteAV sells a good and inexpensive Ku for prime focus dish.

Nice pics, have fun nelson_b

 

[Vipersan]

Hi Nelson m8 ..
As has already been suggested ..that old beauty looks very much like my 1.8m pf in many respects ..
The 6 petal dish itself is seems much like mine ...and has the folded edges to give rigidity ..
It also appears to use 3 glass fibre (black) rods about 15mm thick to support the feed assembly..
I am told mine is an Alcoa ...but still not convinced totally..
My dish is mounted like yours with u shaped bolts to the actual ring back mount ..but there the similarity ends as my polar mount is totally different.
My dish also has holes drilled around the edges of the 6 steel petals to allow for extension pieces that would upgrade the dish size from 1.8 m to possibly 3 m
Gawd I wish I could get my hands on a set of those extension pieces ..
I do hope someone can provide more info on your pf dish ..as this might also help fully indentify mine ..
There are picture of my dish on this forum if you want to search ..or I'll try and find the internal link ?

btw ...this is the very dish I modified last year for C band use ..and you are well aware of the fairly good results I've had ..
I would never use it for ku again as it performs worse than my TD110 ..
but with a custom feed mount ..and a dedicted c band lnb ...the results have been better than I could have expected.
rgds
VS

 

[Vipersan]

I've managed to dig out my assembly manual for my dish ..
Sadly it doesn't identify the dish ...but it does show the polar mount etc ..
I'll scan it and post the results as soon as I can..
rgds
VS
here they are as promised..

 

[nelson_b]

hi vipersan -

very detailed assembly instructions of your dish mount -- i hope someone recognises it --

yes-- from some of your dish pictures that i,v seen the dish part looks almost identical to mine

The feed supports on my dish are around 15 mm hollow aluminium rods ----
i made a C band l.n.b.and feed holder for this dish and the limited tests that i did, showed it to perform quite well -- as channel hopper and satcom 1 commented -- C band seems not so critical as k/u --- i may well return to C band with this dish in the future , as i,v been following how well yours has performed .
but for the moment it remains fixed on 42 east 11054 H 30000 ,
getting it to receive this east beam transponder was not easy - the k/u reception was not up to much with the feed and l.n.b. pictured in post 1 ,
i tried a number of setups before i got weak signal from that t.p.-- then a lot more time
improving on it -- i don,t think i,l get any more out of it , i.m getting almost equal strength and quality on that transponder as i can get with the 1.8 offset

pic 1 shows what i,m currently using -- its the original feed tube, with an invacom feedhorn with the centre ring cut out --- fastened to the back is a darkgold l.n.b with the conical feed cut off --- i tried a standard white inverto c120 -- and also a inverto black ultra with the feed sawn off -- but the inverto,s were not quite as good .
i realise that a different transponder frequency might produce different results - but i was aiming to get the best from that particular one --
pic 2 shows a earlier mix and match feed setup - this worked just as well as the current one but was clumsy and hard to fine tune --
also a couple of screen shots from that time

cheers nelson .b

 

[Vipersan]

Thanks for the update and extra pictures Nelson ..
Even your origional Ku feed mount is very similar in construction to what mine was fitted with ,,
A similar ring /clamp plate arangement to grip the lnb feed ..and a single no frills tube feed ..
In my case there was also a mechanical polaraser (motor drived) ..as it was designed in the days before H/V voltage switching ..
I'm gussing its well over 20 years old ...as I bought mine second hand for around £100 back in the eighties..
I can only assume therefore that mine is made by the same company as yours ...but an earlier edition..
rgds
VS

..I was just thinking ..
pity we don't have a museum section for older sat gear ..
certainly I've aquired a large quantity of old stuff over the years ..
I still have my NEC sat receiver and 2 positioners ..
A Luxor positioner ..
A Discus Elipse receiver ..
A churchill Dmac decoder ..etc etc ..
the list just goes on ..
;)

 

[Vipersan]

...More confirmation ..if any was needed ...

Hope whoever owns these pics doesn't mind them being linked ..

_http://www.kqlz.org/johns/

and just to make me sick ....the extension 'petals' are attached ..

It just makes me want to cry...
rgds
VS

 

[nelson_b]

...More confirmation ..if any was needed ...

Hope whoever owns these pics doesn't mind them being linked ..

_http://www.kqlz.org/johns/

and just to make me sick ....the extension 'petals' are attached ..

It just makes me want to cry...
rgds
VS

Yes --
there is no doubt to me now , that we have the same dish face

those extension petals are brilliant -- that must make the dish around 2.5 metre by the look of it --

thanks for the pictures -- keep searching for those extensions --
someone will have them , stored away in a shed somewhere - gathering dust.

cheers-nelson.b.

 

[BGPv4]

I have a few Alcoas around in my area from the 80's with extension panels on some houses, they extend to 2.4m, i try grab some pics one day.