Please tell me what I am doing wrong with a rooftop install

[STUMPOFWAR]

I live in 19030 (Philly burbs)...almost all of the Philladelphia broadcast antennas are between 255 & 260 degrees from my house and are about 20-25 miles away....which I thought would make my life easier...

OK..... so I bought this antenna...based on some of the reviews and the fact that I couldn't afford a better yagi antenna and I got a great deal...
http://www.amazon.com/Terk-HDTVO-Amplified-HDTV-Antenna/dp/B0009W9WHQ/ref=sr_1_12?ie=UTF8&s=electronics&qid=1279286030&sr=8-12

I initially threw it in my attic on the floor and used my old compass from my Army days to align it and I got ok reception....everyone complains about ABC being hard to get in Philly but it is crystal clear........Fox and NBC are spotty at times, and PBS is marginal.......plus about 6 or 7 other channels that have good reception.

so I went to do a roof mount.......I installed the roof mount kit....I grounded the antenna and I bought some better quality coax to replace the existing coax that wouldn't reach.....it has clear LOS...... and to my dismay I now get nothing!....not a single channel......I have tried it with and without the included amp.....

One thing that may or may not matter....I have a neighbor about ten houses down that has a ham radio tower in his backyard. It is not directly in the LOS (if the antenna is facing 12:00 the neighbors small antenna tower is between 2:00-3:00 about 150 yards away (I can't even see it from my roof)......Again...I have no idea if this matters since the antenna works in my attic....

What am I doing wrong?

[tigerbangs]

A couple of thoughts here: the HDTVo NEEDS it's amplifier to work, but if the coaxial cable is shorted out, as might be the case if you installed your own "F" coax fittings, then you may have a coax drain wire shorting out against the center conductor of the coax cable, or have gotten a bad cable. or, the amplifier may have bitten the dust without any other provocation from you.

The HDTVo would NEVER be my choice for an antenna, since it depends on it's amplifier to provide any reception. In your area, unless you have 3 or more TV sets to power, you shouldn't need an amplifier. If you have return privileges on the antenna: take it, and the wire back, and start over. I would use a Winegard HD-7082p antenna mounted on your roof instead, which has substantial gain without resorting to an amplifier: if you need to power multiple TV sets from the antenna, you would be better served by using a good distribution amplifier like a Channel Master CM341x, where x= the even number of TV sets to be connected.

[STUMPOFWAR]

Thanks for the reply....

1) The antenna's amp seems to do nothing at all........I have turned it off and on and it does not effect the reception at all (other then briefly losing reception any time I turn it off or on). No matter if the amp is on or off it the antenna works in the attic but not on the roof.

2) The cable issue is interesting....I bought a pre-made length from Home Depot....I'll try to swap that out to see what happens.

3) Unfortunately I do not have return privelages

On a side note... since this antenna needs it's amp to work....what does it mean that the the antenna being on or off doesn't matter? If the Amp is indeed toast....what replacement would you suggest?

[STUMPOFWAR]

OK...just checked out the Winegard HD-7082p......and the price scared me....not that it was crazy expensive......but I can't afford to dole out 200+ dollars right now for the antenna and mounting accessories......my wife is one of those millions people who are about to get ejected out of unemployment and she can't even get an interview let alone a job...

I am going to bookmark your post and once we get the $ I'll upgrade the antenna.....but for now I have to make the Terk one work....