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Originally Posted by 1ADAM12  Thanks for sats. NSS looks interesting to me and has strong HEMI footprint. |
Not sure where you're at, but in Denver I have to crank the dish nearly to the snow dump position to get 40.5W - about 10 degrees elevation. Still it's a very strong bird.
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We have a new member who claims his dielectric plate outperforms the normal hunk of fiberglas.
Doctorofsat and others on another site have found substantially better performance on C Band Circular.
This foil pattern is laid out on a 1mm sheet of plastic, Perspex?
They use thin foil.
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I noticed this when it was first posted. My knee-jerk reaction was skepticism, but I explored a little on the web out of curiosity. I found similar posts elsewhere, but when asked about the theory, the poster artfully dodged the question. So this is magic, and I cannot accept that on faith.
Frankly, transforming circular to linear is pretty simple and can be done in many ways. Put your feed in a vise and squash the waveguide at a 45 degree angle to the LNB probes and you'll get decent conversion. So this may provide a circularly polarized signal some encouragement to preferentially polarize linearly. But with the reflective elements, there is a lot of potential for disrupting the impedance of the feed and having frequency-dependent VSWRs. That's pretty scary to me. Even the poster suggests playing with the dimensions to boost/kill certain channels.
The problem with most dielectrics plates used for this purpose is absorption. To quote ADL marketing pabulum:
"The PRO-LINE feeds use a die cast quarter wave plate that does not have the losses commonly encountered when using DIELECTRIC PLATES in C and linear feeds. The increase in carrier to noise ratio is generally in the one dB range making the Pro-Line the clear leader in performance."
I do not have the equipment to verify this claim. ADL's C-band circular feeds cost an arm and a leg. I may be a gullible fool, but the feed does work extremely well.