Why don't you call them and ask what model might help you:
http://www.onfilter.com/

I mentioned this earlier. What did you think of it?
http://www.newegg.com/Product/Produc...w&gclsrc=aw.ds

The ISOBAR has a filter and a good reputation. The only problem I had with mine was that I had to make sure I turned the switch on and off quickly otherwise it would arc and damage the switch contacts. The PC SMPS power supply draws a lot of current at turn-on. My fix was to solder the internal switch on and insert a heavy duty motor starting switch in the cord.

Nicholas Goss had a difficult EMI problem:
Signal interference from air conditioner help please
http://www.avsforum.com/forum/25-hdt...lp-please.html

That power supply isnt high enough wattage to run my computer. I put foil tape over the window in my pc to see if it would stop some of the interference. Didnt work. So I am left thinking it is running over my power lines. I am thinking I need to filter it.

edit: i also checked the monitor and its not the problem either

Ok i am at a loss I bought a couple surge protectors that have 43db of emi/rf noise filtering. I put one on the computer, one on the preamplifier. The computer is still causing the drop in signal quality.

Curing EMI can be difficult, because it can be conducted or radiated or both. Nicholas Goss linked in post #81 certainly had a hard time.

Do you have a link for the surge protectors?

Is the tuner on the same surge protector as the preamp?

I bought these. Yes they are cheap but i didnt have to get them shipped here. surge protector

The computer preamp and tuner are all on seperate circuits in my house. The tuner is not on one of these surge protectors at all.

Rocketfish 2-Outlet Surge Protector (RF-HTS100)
searched for the fine print:
"EMI/RFI noise filtering: Up to 43 dB"

I don't see how it can possibly be as good as one of these
http://www.onfilter.com/

in such a small device that costs so much less.

I am sure they arent better. But the ones i bought i walked into a store and got them off a shelf. The fact that two of them didnt seem to be doing anything makes me suspicios that the interference is going through the power line. I would have expected at least a marginal increase.

I understand your point, but when making a diagnosis you must be careful not to make any conclusions about what it couldn't or could be without further confirmation from additional tests.

Sherlock Holmes quote

"You will not apply my precept," he said, shaking his head. "How often have I said to you that when you have eliminated the impossible, whatever remains, however improbable, must be the truth? We know that he did not come through the door, the window, or the chimney. We also know that he could not have been concealed in the room, as there is no concealment possible. When, then, did he come?"
The Sign of the Four, ch. 6 (1890)
Sherlock Holmes in The Sign of the Four (Doubleday p. 111)

"EMI/RFI noise filtering: Up to 43 dB"
To me, Up to means as much as, but at what frequencies? Is it effective at the frequencies you need? I don't see them providing a chart that shows attenuation vs frequency. It might very well be effective at the frequencies you need, but the EMI could be coming in another way.

Well rabbit i think we may have figured it out. I plugged the preamp and the hdhomerun into the surge protector and my signal shot up to 67%. I guess the hdhomerun was picking up the emi

edit: it dropped back down to 45. bah