My house does not have grounded outlets other than my DIY effort in laundry room and kitchen.mediatechnology wrote: ↑Mon May 27, 2019 10:13 am Kinda OT WRT loss of sync/framing but...
In how many places is the Direct TV grounded?
Does it have a three wire cord?
I just walked outside to check and the satellite dish grabs a ground from the same place as the telephone and power drop is grounded. They ground the coax connector at a simple junction in the antenna wire. They did nice job with loops on either side of the junction. The original satellite dish I installed myself a couple decades ago was not as fancy (or grounded). When I put a new roof on my house, direct TV sent out a crew to move my satellite dish away from the roof surface.Is the dish mount or RF cable lightning arrestor bonded to a different potential?
The receiver is not grounded through a line cord but likely to the satellite dish through the coax antenna cable. It may not even be a simple ground loop. I think there is a separate lump powering the antenna front end. Since my hypex is not grounded I don't see what a loop could be between.Curious about where the loop current(s) are coming from.
I've never had Direct TV.
Seems like it would have both a third wire ground and a ground for the lightning arrestor.
That said my first pass system grounding scheme is mostly floating with the digital decoder powered by its own wallwart and its single ended outputs feeding the hypex differential inputs. So no low Z bond between decoder chassis and hypex ground (probably a small RF cap inside the hypex from inputs to ground, but I haven't seen a published schematic for that.)
I haven't advanced this project further, because it worked so well from the very first power up, and is dead silent using optical for the digital program material.
Since I had the same digital funny business with two different cheap decoders and also different power amps, I am almost tempted to try a new optical cable, but that seems extremely low probability.
I suspect i could get the coax input quiet with better hypex grounding scheme (maybe even power the digital decoder from the hypex 5v rail which would automatically ground it). But not today, did I mention it really sounds good.
Since it went over 10 days last time without a hiccup, this is not a huge inconvenience. I still haven't found a "better" digital surround decoder for less than 10x-20x cost.
JR
PS: My reluctance to put this back on the bench for tweaking is unhooking all the speaker wires... then reconnecting them. I should maybe buy some banana plugs.