My dish is made in Italy, and we picked it up there by ourselfes. It
was the first time that I was at the adriatic beach in January, and it
was wonderful.
I took this dish because it was flat and therewith it was extendable up to, what I expected, above 4m. |
At home, the dish was built up in a friendly company's hall and is
hanging at the crane here
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My first plannings were to make my own rotor |
With a lot of luck - you only get such an offer once in your life - I
got asked if I could make use of an old Rohde&Schwarz "Drehstand",
made 1965. It was used by DLR in order to track the first weather
satellites previously. |
After some work, the rotor was ready to move the dish. Also visible in
this picture is the feed mount that I had to add to the dish. I first
wanted to rotate the feeds through the focus, like a revolver head. |
A solid construction that can even carry the owner |
The old controller was based on pre-pepared stitched tapes and the dish
rotated in 5° steps, which is on 137MHz quite sufficient. And the
control was made with relays only, so I had to make my own controller. |
A flying dish
The dish while on its way to its first outside test |
My first operation on 23cm, using a diagonal waveguide feed.
At this time I was not aware about feed properties, especially that
feed has to provide a clean pattern and match to the f/D of the dish.
You see that the dish is free standing, as it still is today (year 2010). |
My shack during the first operation was placed in an office container -
the hall meanwhile was rented to a company dealing with such- |
The feed assembly in detail
At this time I also still believed that DJ9BV preamps really reach their proposed noise figure. |
Some time later, I meanwhile rented a house with some garden, I moved
the dish to Vierkirchen. DL4MUP/G4HUP helped me a much, I was busy with
my own's house construction and Dave was the main operator during this
phase.
(Picture taken facing north) |
Another picture of the dish during this time. |
Suddenly, one of the original motors became overheatened and broken
since one of the solid state relays that I used for powering got short.
I then decided to replace the motor with a speed controlled 3 phase motor.
You see that I used some equipment from the ongoing house construction for getting access to the motor. |
Dave, DL4MUP (G4HUP) while operating.
TH347 amplifier, FT847, dish controller, NOVA as tracking source and spectran waterfall. |
Another fligth of the dish.
Our house was ready, we had to leave, and this time I got a truck helping me to move the whole dish in one piece. |
At the beginning, I used the dish only to hold a 4wl 144MHz antenna,
since I was more interested in 144MHz Meteor Scatter at this time, and
setting up the cables for 23cm was not possible across the construction
ground. |
In the background: The dish in the far south-west corner of my garden.
In the foreground: A frame for a 1.8m Prodelin offset dish (meanwhile all are sold) |
The dish's early morning shadow on the neighbour house, seen from my shack window. |
Winter impressions |
The cable run from the cable's exit at the house to the dish had to be
lawn mower friendly and easy accessible for maintenance. I am using
boxes with a removable cover that are also used during for example
railway constructions. |
I had meanwile removed the revolver feed and shifted the two for 23cm and 13cm with a screw jack. |
I started expanding the dish to 4.5m.
The expansion ribs are, as the dish is, from stainless steel and I got
them made for EUR 15,- each from a company which has a laser cutter and
a professional folding machine. |
Florian and I while fixing the mesh to the dish. All had to be done on a 1.8m high schuffold. |
Again a view from the street, but now the dish has 4.5m diameter |
During sunset
Some additional weight had to be added to the rear of the dish.
Here you also see the round septum feed (here: 23cm) with chaparral
choke and the new feed mount on a rail that I am using today (2010).
The screwjack is used to shift the feed into best focal position. |
Very late, I found a picture of how the Rohde&Schwarz "Drehstand" was originally used. |
Behind the dish is a box that contains the 13cm equipment and a power supply for 9cm and 6cm. |
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