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Old 4-Mar-2018, 7:59 PM   #7
Retired A/V Tech
Join Date: Aug 2012
Location: S.E. VA
Posts: 2,738
Thank you for making the test and for the TVFool report. Your report shows WTVW with a signal power of -2.2 dBm highlighted in red, which is an overload warning. A preamp is contraindicated unless you insert a custom filter before the preamp to attenuate real channel 28.

I had been wondering about the Televes preamp that adjust the gain. It might work at a location with all weak signals or all strong signals, but with a mixture of weak and strong signals, it is the wrong choice. Your location was ideal for the test; it showed the weakness of the concept. We appreciate the report of your experience; it will help us when giving advice to other posters.

The best clue you gave is when you said you had to rotate the antenna off-azimuth. That reminded me of a case in Las Vegas. The poster was using one of those cheap "150-mile" antennas that also have a preamp with waaaay too much gain. He also had to aim off-azimuth to prevent overload. The only reason to use a preamp with that much gain is when you have a very long coax line after the preamp to compensate for the signal loss from coax attenuation.
If you can not measure it, you can not improve it.
Lord Kelvin, 1883

Last edited by rabbit73; 4-Mar-2018 at 8:27 PM.
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