Geraldo Paiva schrieb: > Hi! All of TVRO Group > > A very Happy Christmas to all of you and a super 2008 and thanks for your > continued group discussions which are of course greatly appreciated by myself. > > I believe the most of subscribers of this group is from USA, where Polarotor > (Chaparral Trade Mark) is largely used to fit dishes intended to pick up C > Band signals from satellites - linear polarization Vertical/Horizontal. I do > not know exactely how is the demand there in USA for devices for the > reception of circular polarized Left Hand/Right Hand signals. But I am sure > that the reception of circular signals is always a problem when using simply > a feeder with a dielectric plate inserted in it. Mainly, when the TVRO > installation is a polar mounted and it is destinated to scan the entire > Clarke Belt , receivng a diversity of signals transmitted in linear (H/V) > and Circular (LH/RH).polarization. If your installation is prepared to > receive linear signals, when your dish moving along the orbit is aligned > with a satellite transmitting circular polarization, the reception of > circular polarized signals is difficult when not impossible. If, in the other > hand, you have got i nserted a dielectric plate into the the feeder to make possible the reception of circular signal, the performance is not quite satisfactory and the reception of linear signals is very, very prejudiced, if not simply impossible, due to high losses inserted. How to solve this problem? > > I am Brazilian and I live in Brazil. We have got here, reaching our area, a > diversity of C Band satellites transmitting linear and curcular signals and > the reception of circular signals is supported by using dielectric plates > with all their disadvantages. I believe the same occurs in USA. One solution > is to have got a dish equipped with a linear feeder and another one with a > circular feeder with a DISEqC switch, for instance, even with the limitation > in its performance when relating to circular feeder using dielectric plate ou > septum or pins. > > What about to have a device appropriate to be fitted into feeder, capable of > being switched between linear status and circular status, depending on > alignment of dish with circular and linear satellite, capable of having got > a high performance in the reception of linear (H/V) signals, and mainly > capable of having got a higher performance in the reception of Left Hand and > Right Hand Circular polarized signals? Besides performing the said functions, > the device should be capable of being actuated remotely in time of operation. > That is not an impossible solution. I have got it. I have an invention > axactely covering all these needs, reservedly tested and proved here in > Brazil by dozen of hobbyists of TVRO. > > I am willing to transfer the entire technology, in the stage it is presently > developed, to a company interested in the manufacturing of it, granting to > that company, at the same time, the rights of worldwide trade. > > I could be contacted thru [EMAIL PROTECTED] or [EMAIL PROTECTED] . My own > site could be visited www.bandaku.com.br if you want. > > Geraldo Paiva/Maceio/Brazil >
Hello Geraldo, thank You for Your mail, it is very informative. As far as I knew until now the problem with dielectric plates was not within C-band by using polarotors but in ku-Band where these plates stand for substantial losses. That was the reason for me to use a Seavey ESR-124HC C-ku-feed which improved the reception in ku-Band substantially. Maybe the reception in c-Band also went better, but I am not quite shure about that. But the most important thing is: they don't use a plate either. I dont know Your system no theirs - I looked on Your website but didn't find any explanations on You system. If You can give a little more explanation, or eaven comparison with the seavey feeds, that would be great! Thank You Wolfgang (from Germany)
