- do you offer local pickup anywhere in North America, including at your distributor's facilities hopefully engaged in this promo? I'd really like to pick it up locally!
This SatelliteGuys special is available for local pick-up at our main distribution facility near Sacramento, California.
- the dish has F/D Ratio = 0.5, while most of your local competitors use F/D = 0.6 for a 120cm dish. Could you give some insight (without using generic terms like "best quality"
), what were the exact factors prompting to pick such F/D Ratio, what advantages it can potentially deliver in fringe areas, when coupled with what LNB models? In what scenarios, for what satellites F/D = 0.6 may fit user needs better?
This model was chosen for superior surface accuracy, side lobe attenuation and hardware design, finish and durability. We independently contract a facility to provide performance testing and ongoing batch samples. These measurements confirm the manufacturers specifications in the controlled test environment. We real-life test using samples of our competitors dishes and with multiple brands of KU band offset design LNBFs.
There is no real "one combination" as there are so many variables in hardware and signal performance which occur during real world testing. An LNBF incorporating a fixed scalar designed for offset design is an off the shelf solution and spec'ed .6 F/D ratio. These LNBFs actually have a wider range for an acceptable F/D ratio, but it is most important to pair for illumination and minimal cross polarization characteristics. The stated .1 difference in specifications of the LNBF and the dish is negligible in performance measurement. The surface accuracy along with the rejection on side lobes due to the lower F/D ratio are the primary strength of this dish. In addition, the lower F/D ratio and similar horizontal and vertical dimensional ratios provides a slight edge for micro-bud testing with increased performance using the regular flat scalar rather than the conical scalar, which does not properly illuminate the reflector.
- What's the aperture angle of this dish, when measured from LNB mount point, i.e. from dish Focal Point? Is it the same in vertical and horizontal plans?
I do not have that data, but the vertical aperture angle would need be slightly greater. Since an offset parabolic design exhibits lower performance (-10% roll-off) near the edges, the gains in scalar design to optimize for this slight variation of aperture angle would be minimized.
- speaking of Offset Dish F/D Ratio, is there a standard requesting every manufacturer to mean the same under this term in dish specs, and also giving its definition? Is Offset Dish F/D Ratio equal to originating Prime Focus Dish's? Why then Prime Focus dishes usually have 0.3, and offsets 0.6-0.7 despite being "cut" from a Prime Focus? What is your definition of F and D for an offset dish? Do you think, other makers in fact mean the same, when posting this spec? How to measure or calculate F and D values of an offset dish, and F/D Ratio?
There is a method for calculating and an industry testing standard for measuring and expressing the F and D and the ratio, which our specifications reflect. I am unsure if other manufacturers and importers list correctly or if it is like the 0.1 - 0.2NR / 70 - 75dB gain LNBF marketing BS that some are currently polluting the market to show their product superiority for the uneducated.
Sorry, I am a LNBF and a STB design geek, but unfortunately I am not an a parabolic RF design guru.... I understand enough to be dangerous and am very competent in choosing RD partners, contracting reliable manufacturing partners and distributing quality products.
Here is some interesting reading for you
http://www.qsl.net/n1bwt/chap5.pdf. Ran across this calculator some time ago, but have never tried it.
Offset Reflector Calculation
- how would you compare this dish to Fortec Star, Azure Shine, and Jonsa 120mm performance wise, by surface geometry accuracy, and structurally? I'm trying to pick the right dish for a multifeed miniBUD. What matching C and Ku converter models would you suggest and why?
Fortec Star brand is no longer imported into North America, but some dealers are still selling off old inventory. The Fortec Star 1.2 is cheaply constructed and lightweight .7t non-galvanized steel. We were the largest distributor of Fortec Star products in North America for several years and we refused to carry any of their dishes due to the poor quality and design. Both Jonsa (once manufacturer of Fortec Star dishes) and Azure Shine manufacture many different models. Some models are well designed with great hardware and others are cheap junk. We partner with Azure Shine on many custom projects including the build on both the 90cm and 1.2M dishes. We pay premium prices for these dishes as these are of "A" build quality and include custom parts not found in any other model. The brackets, assembly hardware and finish are unique to our demanding specifications and the product is superior to any competitor's dish in our market. Our primary markets for the 1.2M are the DTH fringe footprint home user, hobbyist and basic commercial installations. We would not consider this to be a mid or high end commercial product or be applicable for installations continued exposure to extreme conditions.
With that said, your multi-feed project has it's own requirements that are not likely met by a dish designed for a single feed. For starters, I would guess that if you are trying for optimized performance and probably would want to go with a shallow reflector that is designed for multiple feeds rather than adapting a deeper design or lower F/D ratio. Unfortunately, I would not be able to comment on the application of the GEOSATpro 1.2M for multiple satellite reception other than on one set-up I am covering approximately 30 degrees 93W - 123W with a fixed 1.2M with acceptable CNRs on the ends.
Hope that this information is beneficial and helps you decide if this product is a candidate for your project.
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