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Old 9-Jun-2015, 5:23 PM   #7
rabbit73
Retired A/V Tech
 
Join Date: Aug 2012
Location: S.E. VA
Posts: 2,747
You don't need the 8200 because you don't need real channels 2 and 3. KVTU is off the air, and KHIZ probably doesn't interest you.
http://www.rabbitears.info/market.ph...&callsign=knbc
http://en.wikipedia.org/wiki/KHIZ-LD

The 7698 looks good for you.

Quote:
I really only need ABC, CBS, CW, FOX, NBC and PBS, which cover both VHF Hi-Band and UHF; all the transmitters I need are located about 30 miles away at 81° on Mt. Wilson in LA, so I’m looking at a highly directional antenna. According to my report, the strongest signal I need to receive is -71.5 dBm and the weakest is -98.0 dBm.
ABC, KABC-TV, real channel 7, NM 19.3 dB
CBS, KCBS-DT, real channel 43, NM -7.1 dB
CW, KTLA-DT, real channel 31, NM 4.1 dB
FOX, KTTV, real channel 11, NM 16.3 dB
NBC, KNBC-DT, real channel 36, NM -0.2 dB
PBS, KOCE-DT, real channel 48, NM 0.6 dB
http://www.rabbitears.info/search.ph...pe=dBm&height=

CBS looks like the most difficult, with a NM of -7.1 dB. The NM of a signal must be at least 0 dB. The TVFOOL report assumes an antenna with 0 dB gain, so you can improve the NM by adding the antenna gain and the preamp gain, but you must subtract the Noise Figure of the preamp because it adds its own noise that reduces the SNR of your weak signals.

The factors that worry me the most are the trees, the condition of your equipment, and the possibility of overload.

KHIZ has a NM of 30.2 dB. If you add the antenna gain of 10 dB average you get 40.2 dB. If you then add the preamp gain of 25 dB, you are now at 65.2 dB. And finally, if you add the DA gain of 15 dB you arrive at 80.2 dB NM. Your tuner might not like that.



Interpreting Noise Margin in the TV Fool Report
http://www.aa6g.org/DTV/Reception/tvfool_nm.html

Try the new antenna first without a preamp. Then add a preamp. Don't add a distribution amp (DA) unless necessary.

Preamps to consider: Antennas Direct Juice, CM 7778, RCA TVPRAMP1R.

The Juice doesn't have an FM filter, but I don't see any strong FM signals in your area. You could always add a filter later. The CM is redesign. When PCT bought out Channel Master, they redesigned the 7777 and the 7778 but they didn't change the model numbers,
Attached Images
File Type: jpg NMChartC.jpg (71.3 KB, 3282 views)
File Type: gif michaelt84TVF FM est.GIF (133.4 KB, 830 views)
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Last edited by rabbit73; 9-Jun-2015 at 6:33 PM.
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