|Planet Fox > Microwaves
> My Antennas > Fiberglass Ku Band
Fiberglass Ku Band Antenna, ca. 1987
actually have no idea who made this, since it's
identifying marks have long since worn away. I got this when a local
business closed down. I think they were using it for in-store music,
and it was probably aimed at AMC 1 at 101°W, although it wasn't
connected to anything when I took it down, so it's hard to tell how
long it's been since it was used.
This dish was in really rough shape, completely covered
in almost 30
years worth of filth, and the feed support struts and bracket were
really rusty, but everything was definitely salvageable.
I started by pressure washing the reflector, then
scrubbing it down with a wire brush and hot TSP
in preparation for painting. Painting an antenna like this helps
preserve it; the smooth surface layer of plastic has worn away,
exposing the fiberglass strands underneath, and the paint will seal it
back up. I used the same type of paint I used on my old Primestar dish: Rustoleum
but in flat white. This paint is expensive, but I really can't
recommend it enough. I painted my Primestar dish years ago and it still
looks brand new.
I had to use an angle grinder with a wire brush to get
all of the rust
off of the metal parts. Once I had them stripped I thoroughly cleaned
them. These parts were originally galvanized, so rather than paint them
gloss gray like I normally do, I decided to try something new and spray
them down with Rustoleum's bright
which is kind of a lacquer with loads of zinc particles suspended in
it. I've never used it before, but hopefully it'll keep everything from
corroding better than normal paint. Commscope recommends a
"chlorinated, rubber-based paint" for the glavanized parts on their
antennas, but I could only find that in gallon cans.
Like my Primestar antenna, I had to replace all of the
this case, that only consisted of four carriage bolts, two hex bolts,
washers, and stop nuts. This antenna had a fine adjuster too, but I'll
just leave it off for now since I don't feel like welding up a new one.
The feed supports and elevation bracket are held to the antenna the
with double ended screws that have a coarse thread that screws directly
into the fiberglass on one side and a machine threaded screw on the
other side. I don't think you can buy these anywhere, but if I ever
need to replace them I can just drill all the way through and use
This dish has the most unique mounting bracket I've ever
most antennas have a collar that gets tightened around the mounting
pole, this one has an eye bolt that hooks around a large bolt driven
through the mounting pole, and is tightened by tightening the eye
bolt's nut. It's kind of weird, but it seems as secure as any other
mount I've ever used.
The feed that came with this dish was in good shape, in
that it didn't
have any corrosion, but like most feeds this age the plastic cover had
all but disintegrated from exposure to sunlight. I'm going to expoxy
some new clear plastic over it eventually, any plastic will do but the
clear polystyrene used for food packaging is especially well-suited.
For now I'm going to use my Chaparral Ku feed. I was really surprised
to find that the LNB, a Norsat
model 9000A covering 11.7-12.2 GHz with an 0.8dB noise figure still
works, and quite well I might add. Old Japanese manufactured LNBs like
this are legendarily reliable, but since the feedhorn's weather cover
was shattered and there was no cable or protective cap on it's output I
expected some water damage. Local oscillator drift measured a
respectable +/- 300kHz. The LNB provided the only indication of this
dish's age, the serial number indicated it was made in 1987, making it
27 years old when I got it. I wish everything was this reliable.
For now I'm using this dish, combined with the Chaparral
Ku feed and an old Primestar LNB to receive the PBS channels on AMC 21.
After cleaning and repainting
The original LNB, a Norsat model 9000A, manufactured in 1987. It looks
terrible, but works perfectly.