SS-3000 Amplifier Test?

[WaveMechanic]

In NYC zip 10022 using an SS-3000 after careful aiming I get low (25-35%) signal strength at best, and intermittently get zero signal, on channels across the VHF and UHF bands (2, 7, 11, 13, 28, 44, etc.)

In the past I've checked all cables and connections without finding anything wrong. Today I tried bypassing the supplied PI-1000 power injector and power supply with a barrel connector between the antenna coax and the coax to my TV, and discovered that I get the exact same results whether the power supply and injector are in circuit or not.

Using a VOM I found the power supply output measures 19.5VDC (although it is marked 15 VDC) at the input to the PI-1000, and the LED on the PI-1000 lights up clearly. The coax to the antenna has 19.5 VDC at the antenna end, and there's no DC on the coax from the PI-1000 to my TV. I've also confirmed that 44 mA flows from the power supply through the PI-1000 into the antenna (dropping the voltage to 18.5 VDC) vs. 60ma listed in the SS-3000 specifications.

Other posts in this forum suggest that bypassing the power injector should result in a 85% signal loss, and I'm not seeing any. I've had the antenna for over a year and use it infrequently, but I've never had any different results using it in the past (i.e. nothing "changed suddenly").

Are there other tests you can suggest to determine if the amplifier in my antenna is working? And, if it is faulty, is a replacement part available?

[winegard]

Good morning WaveMechanic,

According to www.antennaweb.org for your zip code of 10022 you are approximately less than 2.0 miles from your TV stations. It is very possible that with the antenna powered up you have too much signal and with the antenna not powered up we do not have enough signal. Depending on your TV set or converter box the 25-35% meter reading is most likely a reading of the data stream and not an actual voltage reading so that is why it does not change when the antenna is powered up or not powered up, because you are not changing the data stream.

Power up the antenna again and then try reducing the signal going to the TV by installing a 3.0dB or a 6.0dB or both (9.0dB) in line attenuators between the TV connection on the power injector and the TV set. If this does not help, send a copy of your receipt for the SS-3000 and a copy of your email to the Winegard Warranty Department asking them for an RMA number so you can send your SS-3000 antenna in under an have Winegard check the antenna out to make sure is working properly. Email your receipt to warranty@winegard.com or if you wish fax it to Winegard Warranty Department 319-754-0715.

[WaveMechanic]

Thanks for the suggestion, winegard - this forum is an outstanding example of good customer service.

Not having any inline attenuators readily available, I connected two 3-way splitters (3.5dB loss each) and a third splitter with a -18dB tap in line with the coax from the PI-1000 to my tuner input. When I disconnected the power supply from the PI-1000 I lost reception of a low-power analog station, which indicates that the amplifier is in fact working properly. But throughout these tests DTV reception remained, as always, intermittent.

After considering your helpful remarks and the detailed signal strength maps for my location on TVFool, I'm led me to believe my problem is not with signal strength, but rather severe multipath interference. I am located on the 6th floor of a large steel-framed 10-story apartment building, surrounded by 20-30 story office and apartment buildings, and the primary transmitter location (the Empire State Bldg) is in the opposite direction (southwest). So the signals that reach my location are reflected off many buildings.

So thanks for your response, but I don't think sending the antenna back to your service department would help with that, and in any case the warranty expired some time ago. I may try to locate it to a sheltered area on the top floor of my building where there is clear LOS to the Empire State Building, and see if that helps. If there are any other suggestions you can make about mitigating multipath interference with DTV I would appreciate hearing them.

Thanks for the help!