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Old 1-Jul-2013, 12:32 AM   #42
Pete Higgins
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Join Date: Apr 2013
Location: California, 58 miles @112 degrees from Mt. Wilson
Posts: 83
I’m running out of antenna real estate

tripelo,

Quote:
“Probably, the noise figure of the PCT MA2-M is better than either of the WG preamps.”


Yes, but just barely. The PCT MA2-M’s are rated @ 2.7 dB average NF, 4.0 dB max. & the Winegard HDP-269 is rated “Average Noise: 3dB”. The AP-2870 is rated “Noise: VHF 2.9 dB / UHF 2.9 dB”. I don’t need the NF-471 or FM traps with any of the PCT amps. They just don’t seem to overload. I run one on each of the three antennas on my TV tower. The 91XG/MA2-M & Y10-7-13/MA2-M outputs are combined in a UVSJ & yes, all three amps are powered through a separate run of coax. I built a plastic box with a LM7815 and 4 chassis mount ‘F’ connectors. Basically, 20 VDC in & 15 VDC goes out to each amp. The FM antenna/MA2-M shares the rotor/mast/power distribution system but uses dedicated RG-6 down lead, PCT MA2-4P distribution amp and through house wiring.

Quote:
Whereas the return bandwidth is lower than ordinary TV signals, in the range of 5-42 MHz.


You are right about the return B/W frequency range, but when I tried using them behind the HDB8X panels, they didn’t appear to provide enough isolation. Switching to the pre-amps. worked much better. I'll try them again.



Quote:
“…both the 2-meter ham antenna and the CM-4228 may be interfering with the YA-1713”


I’m sure you are right, but I’m running out of antenna real estate. Check out <http://www.highdefforum.com/local-hdtv-info-reception/141103-solid-signal-own-brand-2.html> posts #20 – 24 for pictures of my antenna farm.

Originally, the pushup mast held the Cushcraft A147-20T 2 Meter beam, Winegard HD-6065 10 Element FM Antenna and rotor. When I decided to “play” with OTA I knew it wouldn’t support everything, so built the OTA TV tower.

My main aluminum crank-up tower supports an 11 meter Wilson Shooting Star that’s been re-dimensioned for 10 meters. It is turned by a tower mounted Alliance HD-73. I have a mast mounted 50 ohm coaxial relay (w/’N’ connectors) to switch it between vertical & horizontal polarization. Since I had the tile roof put on I have to climb the tower to work on that antenna. I was up there last summer and my wife came out, saw me, and went ballistic. That’s in part why the TV tower can be lowered & raised with a winch.

When I moved the FM antenna to the OTA tower, it left too much unused mast on the pushup to resist so I mounted the CM-4228. Worked great for the San Diego UHF stations but propagation had to be good to get 8 and/or 10 so I added a dedicated Hi VHF antenna. Turns out, when propagation is good, they both get 8 & 10 when it isn’t, neither gets them. The YA-1713 just gets them sooner and holds on a little longer.

When I can get some help lowering the pushup mast I want to mount a ‘J’ pole and move the 4228 down below the rotor. The rotor on the push-up is a 40 year old Radio Shack Cat. No. 15-1220 and I don’t think it will handle as long of a mast as I’d need to get proper separation.

Believe it or not, I’ve still got a Cushcraft 215WB Boomer that I can’t find a home for.

Nothing has been done for several days. It was 107 deg. here yesterday and its 105 now.
Attached Images
File Type: jpg OTA TV & FM Wiring Diagram Pictorial #4.jpg (277.4 KB, 5265 views)

Last edited by Pete Higgins; 1-Jul-2013 at 7:49 PM. Reason: Return bandwidth
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