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Old 16-Aug-2013, 6:23 PM   #54
Pete Higgins
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Join Date: Apr 2013
Location: California, 58 miles @112 degrees from Mt. Wilson
Posts: 83
tripelo,

That’s a lot of separation between your long Yagi’s. Do you think that ~1.5 wavelengths of spatial diversity is mitigating your frequency selective fading? It would certainly help explain improvements in excess of simple combining gain.

I received my second RCA preamplifier on Monday. I dropped my tower and removed the PCT MA2-M’s from my 91XG and from my Antennacraft Y10 7-13. I made up new antenna cables w/boots and installed the RCA TVPRAMP1R amplifier on the mast midway between the two TV antennas. I configured it for separate inputs with the FM trap selected.

I decided to use the supplied power supply/inserter. The run from the garage to the amplifier is ~125’ through copper coated steel RG-6 so I was expecting I might encounter too much voltage drop. Turns out, it works just fine. The RCA draws <80 ma and my 3 PCT MA2-M’s were drawing almost ten times as much.

My Winegard AP-2870 overloaded with my 8-Bays on my push-up mast, but it overloaded a lot worse on the tower with the 91XG /Y10 7-13, so I was half way expecting the RCA might overload on the tower as well. No such luck. Since I installed it, it’s been rock stable with no signs of overload what so ever. When I was first setting up my system, because of the big price difference, I never would have considered buying the much cheaper RCA amplifiers. Just goes to show ya!

Subjectively, I think the RCA is outperforming the PCT drop amps. especially on VHF. Rescanning I’m picking up 1 low VHF channel, 1 high VHF channel and several UHF channels that I haven’t received in the past. Of course I’ll have to learn new languages to understand some of them. The RCA is specified to have 1 dB more gain on VHF & 7-8 dB more on UHF so that could be the reason with my long cable runs. The PCT’s are specified to have a Noise Figure of 2.7 dB (avg.) & 4.0 dB (max) with no distinction between VHF & UHF so it could be that I’m seeing a NF advantage. My main concern was with overload from my two strong local stations. So far, neither RCA amp. has exhibited any signs of overload. In the same situation, both of my Winegard’s (AP-2870 dual input & HDP-269 single input) displayed debilitating overload. I would sure like to know where the 1 dB compression point is reached with this design.

Looking forward to your next post.

Edit:

I calibrated my NTE/ECG U-106 rotor mid July. When I turned it to 090 deg. to drop the tower I noticed the array was pointing ~110 deg. I parked it so the antennas would be pointing straight up, lowered the tower and made my changes. After I raised the tower I had to recalibrate the rotor again. I’m not impressed with the accuracy of these 3-wire rotors. My 40-50 year old 5-wire rotors always point where they say they are pointing.

Last edited by Pete Higgins; 16-Aug-2013 at 7:05 PM. Reason: Add Rotor update
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