If you are wondering about my concern with the 7777, here is the math:
your report for reference:
http://www.tvfool.com/?option=com_wr...e2cb74ea324603
KVCR Noise Margin is 61.2 dB + antenna gain of 13 dB = NM 74.2 dB, which is overload when the antenna is aimed at KVCR. When it is not aimed at KVCR, the strength of the signal depends upon the antenna pattern.
Interpreting Noise Margin in the TV Fool Report
http://www.aa6g.org/DTV/Reception/tvfool_nm.html
KVCR has a signal power of -29.6 dBm = 19.4 dBmV
Max input of the 7777 = 15 dBmV
http://www.channelmaster.com/TV_Ante..._p/cm-7777.htm
Quote:
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This antenna amplifier is a high gain, low noise preamplifier used to allow weaker signals at the antenna to be amplified to a viewable strength, and is ideal for installations in which all broadcast towers are located at a distance of more than 80 miles......Due to the high gain output of this product, it can result in over amplification if not used in the appropriate scenario. Over amplification can cause issues with the television tuner’s ability to receive and display some or all channels.
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Even without adding ANY antenna gain, KVCR will overload the input of the 7777.
KVCR signal power = -29.6 dBm
-29.6 dBm + ant gain 13 dB + preamp gain 30 dB = +13.4 dBm; tuner overload
even without adding antenna gain
-29.6 dBm + 30 dB preamp gain = +0.4 dBm; tuner overload
This calculation assumes that the tvfool report is accurate for your location, which isn't always true. But, it is necessary to be aware that a small amount of overload will affect the reception of weak signals even if the strong signals are not affected.
ATSC Recommended Practice:
Receiver Performance Guidelines
Document A/74:2010, 7 April 2010
RECEIVER PERFORMANCE GUIDELINES
5.1 Sensitivity
Quote:
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A DTV receiver should achieve a bit error rate in the transport stream of no worse than 3x10E-6 (i.e., the FCC Advisory Committee on Advanced Television Service, ACATS, Threshold of Visibility, TOV) for input RF signal levels directly to the tuner from –83 dBm to –5 dBm for both the VHF and UHF bands.
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5.2 Multi-Signal Overload
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The DTV receiver should accommodate more than one undesired, high-level, NSTC or DTV signal at its input, received from transmission facilities that are in close proximity to one another. For purposes of this guideline, it should be assumed that multiple signals, each approaching –8 dBm, will exist at the input of the receiver.
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You should not need to use the 7777 AND the 3410 with your signals, which is why I asked about how your equipment is connected.
When the antenna is aimed at KCIO:
-57.7 dBm + ant gain 13 dB + 30 dB preamp + 15 dB 3410 = +0.3 dBm; tuner overload
Looking at your FM signals, KDEY-FM has a signal power of -23.6 dBm:
http://www.fmfool.com/modeling/tmp/b...7/Radar-FM.png
The 7777 says FM trap >15 dB
-23.6 dBm - 15 dB trap +30 dB preamp + 15 dB 3410 = +6.4 dBm at the tuner input
KDEY-FM is on 93.5 MHz; its 2nd harmonic is 187 MHz which falls on channel 9 (186 TO 192 MHz), which makes interference possible.
Testing for DTV Interference
http://www.tvtechnology.com/expertis...ference/202503