Recent content by caddata

Ah...To ground or not to ground, that is the question. Actually a longtime debate between amateur radio hobbyists for decades upon decades. Argument (1): Ground it to provide a path to ground for static and lightning. Argument (2): Ground it and you're just asking for a lightning strike...

No reason you can't give your dinged, battered, and abused panels a "new lease on life" by rolling them flat. I did a patent drawing a long time ago for a machine that made expanded metal. It pierced, stretched, and the last operation was to flatten and straighten with several pairs of...

Not compound curves. A parabolic dish is compound by nature in that it curves in two directions---"bowl shaped" in one direction and parabolic in the other. An "English Wheel" is the metalworking tool used for compound curves. It takes years of practice and lots of wasted sheetmetal to become...

Oh no please don't tell us if you decide to use Popsicle sticks because, if you do, from that point on you'll be "PopsicleNMore" in my mind. Sorry for the sick humor.

If you're talking of the "Local Channels", you're out of luck. They're "Spot Beams" that are transmitted with a highly directional signal to a limited area. You may be lucky to find a wild feed somewhere, but they'd be unreliable for daily viewing. I hope that local channels will be able...

Bad info. Don't know where you got your info, but my spec. book shows 6061-T6 alloy, which will work in most instances as a substitute for carbon steel pipe in the diameters needed to fit mounting brackets on small sat. dishes and affords corrosion resistance.

Rigid electrical conduit is also available in aluminum. It has the same dimensions as Sch.40 aluminum pipe, and will be threaded on both ends. Will be expensive wherever you buy it, but it won't rust.

Some form of terrestrial interferrence, like radar or phone link. Had a similar problem with my in-laws TVRO system back in the 1980's. Wound up building a 10'x10' aluminum window screen wire shield on a PVC pipe frame between their dish and the source, which was a terrestrial microwave...

Formulas that I used called for my sub (virtual) reflector to be 6" O.D. with a .4375" rise in the center. I didn't even try to plot the profile as a hyperbola, I just fabricated it from a piece of .015" aluminum sheetmetal laid out (developed) using an exercise in an old drafting textbook...

Information in picture caption may be bogus. I doubt the manufacturer would have spun a spherical reflector because the efficiency of the dish would have been reduced to that of a six foot parabolic. Microwave signals reflected near the periphery of a spherical reflector arrive at the focal...

Long ones can sub for short ones if you don't relocate the attachment points. Relocating the attachment point further towards the edge of the dish gives more mechanical advantage to move heaver dishes or give more counts between sats on smaller dishes. They all use similar components the...

I experimented with a Cassagrain subreflector on a 10' FRP dish in 1983. Geometry and instructions were supplied by Butch Simpson, in one of his experimenter's guides. Butch worked for HP in Greeley, CO for his day job and sold experimental TVRO kits as a hobby. Several of his circuits were...

Sorry to say I never got past the early design stage. Saved a 1.8M from the scrap heap and gave the 1.2M to a fellow member of this board. Harold