I recently installed a Philips MANT940 antenna and reception is okay, but nothing great. Lots of channels come and go from time to time. Assuming part of my problem was due to a 4-way splitter, I purchased a Winegard AP 8275 amplifier. I installed it and got no signal at all. I checked to make sure it was installed properly and it was so I assumed it was a bad unit. Then, I went to Radio Shack and bought one. I can't remember the model, but the guys said it was what I needed. I installed it and it didn't work either. I was looking online and noticed it was UHF only. Is that the problem? Does anyone know why the amplifiers are working?