directv receiver long run without noise

[cjkpkg]

Not sure where to post this but here it is...

I have a directv receiver in room A and I listen primarily in room B. All of the stuff in room B is DIY from pre amp to power amp. I am running a long line of RCA out from the DTV box to the pre amp in room B. The signal has massive 60hz buzz on it which is driving me crazy.

Suggestions welcome.

Maybe digital out to room B and a DAC to the pre amp?

Pre amp is a tube pre...power amp varies...so I would need to convert to analog before the pre...

[SY]

Transformer coupling. I had the same problem before I built the Heretical with a Jensen input transformer. The other place to execute this is along the coax feed, very often the buzz source- Jensen makes a very nice isolator for that.

[cjkpkg]

OK so I found the isomax/Jensen units...basically 2 JT-11P-1HPC's.

I could either build a box or get the isomax unit.

Question, would I install this before the preamp or between the preamp and the power amp?

[kenpeter]

The dish is grounded outside (probably to the meter box).
For lightning reasons, or whatever. Its an actual law...
Safe it might or might not be, but its a huge ground loop.
Its a big #10 copper wire, if I recall.

After confirming a coaxial ground block and ground outside,
You might try a 2 to 3 prong power adaptor on an affected
receiver inside. Just to confirm, not as a permanent fix. You
need transformer isolation, and thats expensive...

Direc satellite techs sometimes just bend the ground until
it breaks off the reciever's power cord. The inspectors will
only look at grounding outside. The tech will not get paid
unless he can stop the buzzing, so he does what it takes
to get paid and get to the next job before anyone realizes
there's a serious problem with the whole system...

On multistory houses, the installer knows the inspector
can't see, so he makes a fake ground block by the meter.
And (if he grounds at all) will ground the coax to a water
heater or air conditioner in the attic instead...

Direc Installers (working for MASTEC) get cheated out of
their pay constantly. And soon learn not to put any effort
into any project that might arbitrarily, randomly not pay.
Buzzing = not paid, fake or broken grounds = $$.

They "backcharge" an installer $5 per reciever if the customer
has a cell phone or pay-per-view incompatible IP phone that
can't dial out. If thats not arbitrary....

[cjkpkg]

Interesting...I know a couple folks that have ditched all pay TV and do exclusive web streaming from netflix, hulu etc...

It seems that is getting more and more feasible.

I think I am going to try out some inexpensive Edcor iron WSM10K/10K at $10 each I figure pending the results will justify if I will spend a couple hundred on the Jensens...

I would hate to spend more and have little effect.

[kenpeter]

The ground loop is from a household grounded
receiver,TV, DVD, Game, or Stereo, over the
coaxial cable, to the Sat groundblock outside.
Which then bonds back to the house ground
with the aforementioned #10 solid coppper cable

But you can't break it (the loop) here.
Uses DC voltage to power the LNB and
to switch polarization. 13 or 18V = Left
or Right circular polarization.

[cjkpkg]

I received the Edcors today and soldered up a little test rig with some aluminum "L" I had laying around.

This has eliminated the buzzz completely. They are sensitive to noise and do not do well near power supplies...especially toroids.

I was able to place the isolation transformers a couple feet from the preamp and then run a short pair of RCA cables from the transformers back to the preamp.

[Pano]

Good work! Glad to see you got it sorted.
Yes, the line transformer will pick up hum from power transformers if too close. The shielded ones are better for that.

[kevinkr]

Funny after five years with DirecTV my wife and I have nothing but good words for the quality of their service. (And the local techs which we have needed just twice in that time, once for an upgrade, the other for a repair..) Our previous cable service neither matched the video quality (SDTV here still) nor their reliability and were somewhat more expensive for much less choice. Internet TV is not an option for us - 12500ft of copper to the central office does not make for very fast DSL unfortunately and FIOS is not an option around here or we'd have it.