Sam:
Thank you for telling us the good news that the DB4E works well for you with one TV.
An amp at each TV is not a good idea because the signals should be amplified before going through the splitters and long coax runs to the sets for best signal quality as GroundUrMast said in post #16. Just one amp, if needed, should be near the antenna, if the sets with the weakest signals are giving you a problem. The technical reason has to do with Noise Margin and the system Cascaded Noise Figure; I will not bore you with the links unless you ask for them.
When you add the other TVs you will need a 4-way splitter or two 2-way splitters, depending on the coax runs to the other TVs. Try that without an amp at first.
If you use a 4-way splitter, the four outputs will all be 7 dB down from the input. The total loss for the signal at the end of the 100 ft run will be 13 dB (7 dB for the splitter and 6 dB for the coax) that must be made up by the preamp to be back where you are now with one set. If you use two 2-way splitters in cascade, you will have three outputs, two 7 dB down and one 3.5 dB down that can be used for the 100 ft run.
Instead of a preamp, which gives a little more gain, you might also consider using a distribution amplifier like the CM34XX series. A distribution amp combines the amp and splitter in one unit. The 3414 has four outputs all of equal strength. Each output is 8 dB stronger than the input.
If you use a CM3412 you have 2 outputs that are 11.5 dB stronger than the input. One output can be connected to a 2-way splitter giving you three outputs: two 8 dB stronger than the input and one 11.5 dB stronger for the 100 ft run.
Grounding an antenna in the attic is not required by the code, but the coax should be grounded in some way for electrical safety. I have strong feelings about that as you can see from this thread:
60 miles away from broadcast tower..help
http://forum.tvfool.com/showthread.php?t=12019
and in particular my posts #22 and #25 on page 2:
http://forum.tvfool.com/showthread.php?t=12019&page=2
In reference to the closet, I was thinking along the same lines...the preamp would be out of sight. There is something called the WAF.....Wife Acceptance Factor. In your case, it would be the Fiancée Acceptance Factor. Women rank making it look "pretty" more important than "practical."
http://www.weddingwire.com/wedding-f...570f69ba2.html
My wife is from Birmingham, AL. She tolerates my antenna experiments because I was able to set up an OTA system for use when the cable is out or during a power failure. I'm lucky because she even bought a signal level meter for me to make antenna measurements.
Best regards,
rabbit