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Old 7-Jun-2019, 11:23 PM   #19
Retired A/V Tech
Join Date: Aug 2012
Location: S.E. VA
Posts: 2,738
Originally Posted by newmguy View Post
yes i tried this with 37db attenuation. Modulator channels were snowy but this didn't help. I am trying to get CITY TV, channel 44, 653 MHz. Without the modulator it comes in. I even get Fox and ABC but not CITY-TV with the modulator connected.

yes the clearstream 4V attic antenna is just for the bedroom tv. The modulator output is split into two. One feeds the whole house through a dist amp, and the other is attenuated and then combined with the LTE filtered antenna signal to the bedroom tv.

The output of the two goes to the bedroom tv and is independent of all other tv's in the house.

I revised your diagram to match your description. Is it correct?

How do the modulator channels look on the other TVs?

You have probably eliminated the overload possibility with the attenuator, but the modulator could be putting out spurious signals in the UHF band, as ADTech has indicated, that would interfere with the reception of your desired UHF channels.

Are you still in Newmarket, ON? Is this report correct for your location?

These are suggestions made by ExDilbert:

Originally Posted by ExDilbert
It sounds like the RF modulator is generating out of band signals. That's not uncommon with cheap modulators. I see several options to solving the internal interference being caused by the modulator. One is to purchase a better modulator (or 3 modulators) that do not generate out of band signals. An LTE filter will still be required if they are used above channel 39. The other is to purchase a custom band pass filter for the channels being used by the current modulator. (That will likely cost $100+.) Another is to use HDMI, component or composite video inputs (plus audio) on the TV. The last option is the best choice since it will provide a better picture and eliminate any chance of RF interference. If the TV does not have enough inputs, it may be necessary to obtain an external switch.
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File Type: jpg newmguyTVFdiagram2.jpg (51.5 KB, 1766 views)
File Type: jpg newmguyTVReport.jpg (175.8 KB, 1434 views)
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Last edited by rabbit73; 8-Jun-2019 at 1:05 AM.
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