On Sat, 16 Sep 2023, Ulrich Speidel via Starlink wrote: > On 15/09/2023 11:29 pm, Alexandre Petrescu via Starlink wrote: >> >> I must say that I dont know whether the original 'DISHY' is simply a >> dish antenna with an analog amplifier and maybe some mechanical motor >> steering, or whether DISHY includes a computer to execute some protocol, >> some algorithm. In addition to that Ulrich says, the dishy is a full computer, it's output is ethernet/IP and with some adapters or cable changes, you can plug it directly into a router. There are numberous teardown videos on youtube now, for both the original and the 1st of the rectangular dishys, they will show you how complex the system is. David Lang > > It's a phased array, not a dish, even if it looks like one. It consists of > 100's of fingernail-sized antenna elements that: > > * during transmissions, have an individual phase delay added to the > signal transmitted from that element, in order to permit > transmission of the combined signal from all elements into a > particular direction. > * during reception, have an individual phase delay added to the signal > collected by that element, before the signals are added to obtain > the combined received signal. This allows reception from a > particular direction. > > Dishy's main direction of transmission / reception is therefore not its > surface normal - this simply points to the area of the sky where Dishy > expects to see most satellites (a function of geographical latitude and > constellation design - essentially straight up in the tropics, and elsewhere > in the direction of the 53rd parallel, which corresponds to the predominant > orbital inclination in the Starlink fleet). The actual tracking is then done > with the phased array without mechanical movement by Dishy. > > From what I've seen, Dishy seems to consume more power on receive than on > transmit - that's if you actually download stuff. This is somewhat > counter-intuitive if you're used to putting link budgets together. But I'd > attribute that to a higher degree of digital signal processing required on > the receive and demodulation path. > >