AP8800 Pre-Amp

[DONWOL]

I just purchased this unit and installed it today. It made my reception almost non-existant. I am about 42 miles from the TV transmitter site. I have 8 TVs running off the antenna going through a Channel-Master 8 way amp. I have 4 more TVs to connect so I purchased the AP8800 so when I hook up these my reception will remain good. Well the unit appears not to be working. I hooked everything up correctly, plugged the power supply in and the red LED on the PS-1503 connector came on. I turned on a TV and the signal was fading in and out with snow and lines running across the screen. It was the same on all TVs in the house. I also couldn't receive any HD channels which I could before. I disconnected downlead from the Winegard PS-1503 connector and ran this directly to the 8 way splitter and saw no change in reception. I bypassed the 8 way and ran it directly to a TV and only saw a slight improvement, still no HD channels. I then disconnected the Amp on the mast and connected the coax together there and hooked the coax back to the 8 way and everything works as it did before I installed the AP8800. What do you think is the problem?

[winegard]

Good morning DONWOL,

The Channel Master 8 way amplifier will only handle 3dBmv of input signal per channel and has a gain of 22dB.The AP-8800 has a gain of 17 dB on VHF and 28dB of gain on UHF which the Channel Master amplifier can not handle. You are overloading the Channel Master amplifier with too much signal from the AP-8800.

When you disconnected the downlead but left the AP-8800 preamplifier in the line you reduced the incoming signal by at least 85% since the signal has to go through non powered transistors. This naturally would cause a very weak signal going into the 8 way amplifier. When you ran from the AP-8800 to the TV set was the PS-1503 connected up? Also we need to check that we have +15 volts DC at the end of the coax cable going into the preamplifier to obtain full gain. There could be defective connector or a break in the cable not allowing the +15VDC to go to the preamplifier.

[DONWOL]

Yes I did run it with just the amp and PS-1503 connected to just one TV and I had the same results. When I get home I will check the voltage at the amp on the mast and let you know the results.

Thanks, Don

[DONWOL]

Ok I checked the voltage 15.24v at the amp up by the antenna. One thing that I didn't check the other day was the picture quality on other channels. My first check was on Ch2, this was the worst, picture jumping horizonal lines moving upward on the screen. Checking the other channels the picture was better. The horizonal lines were barely visible but there was an inferference pattern like maybe DC voltage. These results were with the antenna, amp and one TV only (no 8 way). I was looking for an antennuator last night but knowbody in my area had one. How do I know the amp is working properly?

[winegard]

If you have the+ 15.3 VDC going into the preamp hook the preamp up and check the picture quality of your TV channels. Unplug the wall transformer and if your TV pictures get worse the amplifier is working. If the pictures do not change or get worse then there is a problem with the amplifier.