1098 thumps

[DrJRapp]

Something new has crept into the output of my 1098 as I was listening to music tonite. I get staticy thumps through the left center and right channels that occurr as twins. It's sort of like a heartbeat, da dum, da dum, da dum, occurring about 1 second or so apart. They are quite audible and seem to be dependent on volume setting. I suspect it is originating within the 1098 since my center is powered by a different amp than my mains.

Anyone ever experience anything like that?

[DrJRapp]

Around 11PM the thumping stopped. This leads me to believe that there is something outside my system interfereing. The search begins today.

[Pieter]

Best of luck Inspector Sleuth.

This has the potential of a circuitous detective pot boiler. If it's not the butler, then perhaps the mechanical automated dumbwaiter...

[Cracking Oboe]

Hi Jerry,

Very interesting... 11 P.M. is the start of the "magic time" when our system is dead quiet and starts to sound its best. Maybe it's the gravitational effects of the sun or the moon? Or maybe it's the next door neighbours short wave radio getting turned off when he goes to bed.
What source were you using? Did it happen with all sources? Did you turn the system off and on again and was it still there? Any new electrical appliances in the house? Do you have air conditioning that has just operated for the first time this year?
Some of our intermittent noises are related to our furnace starting up. The old furnace self destructed and was replaced... we still have the same problem (it messes up our cable TV reception too - static.) Any ideas?
I'm sure it's tough for you Jerry... in some ways it would be nice to have the thumping come back to find out what it was, and make sure it wasn't the 1098. In other ways, it would be nice if it never happened again.

Cracking!

[DrJRapp]

Well, last night it started in around 8pm and was still going strong at 3AM when I finally found the cause. Or at least what I think is the cause. I disconnected and reconnected just about everything in my system more than once until I finally disconnected the satelite TV connection from the surge arrestor in the Monster HTS 3600 filtering power supply. Having previously read about hum and noise issues caused by variuous Sat and TV boxes, the input to my Sat box was one of the first things to get disconnected. I had forgotten that particular lead was coming fom the 3600 and not directly from the dish. It wasn't till I was reaching despiration that I actually found the connection was INTO the 3600 from the dish and disconnected it. I know that was the sorce of the noise because if I reconnect everything the heartbeat returns. I don't have a clue how that noise is then finding a path into my 1098.
Now here is the crazy making part: I actualy have 3 LNBs (antenna amplifiers) in my Dish setup, two on one dish and one on another. (Those of you with Dish Network and and older HD box know exactly what I'm talking about). There is an auto switching device that selects between the three depending on what channel one has selected on the receiver. One of the three LNBs must be breaking down and feeding some noise transients into the ground. But it only happens when one of the three receivers in the house tuned to that channel bank. That is why it was only occurring at some times, and not others. This is an event that my 15 YO son calls "totally random"!