I am sorry I missed this thread for so long. I have some clarifications to add.
On 02/28/05 09:47 ET, barlow said...
Or as bookaroni pointed out will the preamp if
unpowered occult
the signal in any way.
It looks like leaving the Preamp unpowered is
okay and it will just act
as a pass through when unpowered.
NOT! See below.
I was afraid
it would also introduce a
"db loss" when unpowered.
TOTALLY!. See below.
A basic issue is being overlooked about the power supply and amp. The amp is inside the antenna and it needs power to come up the cable to it. With no power, it not only does not amplify, it hardly lets any signal leak through. An amplifier with no power supplied to it is a pretty good attenuator, so if you remove the power supply, you should get holy terrible signal out of the antenna. Much worse than if you could get into the antenna and locate the input to the amp that is hidden inside there. This would be just like adding any amplifer to an antenna system, but not plugging it in.
Go back and look at what Winegard wrote -- they tell you that you can use an additional amplifer AFTER the power supply, i.e. in that case the supply would have to be in the attic, where you would also put the added amp (for lowest noise, put the amp as close to the antenna as possible, not down the line where the signal has fallen and signal to noise is therefore worse).
Bookaroni's solution works because the power supply, even in the basement, is sending power up to the antenna. If he unplugged the power supply, his signal would fall drastically. In fact, bookaroni, please try this and report back!
Coincidentally, the voltage available from a satellite line is enough to run the amp. Has anyone out there ever seen a diplexer that passes voltage on all ports? I haven't; I have seen the occasional TV antenna input that actually shorts out DC and needs a DC blocker if DC happens to be on the line, so someone would have to have a need for thousands of all-ports-passing diplexers for even ONE to be out there.