Combining OTA antenna and modulated channel

[Gopowers]

Hello all! New here - needing some help on an existing install:

I work in a commercial building that houses a non-profit organization. We currently have new flat-screen displays across our campus.

What we are hoping to do, but have yet to be successful, is combine a modulated signal (that shows conferences and various announcements) on Ch. 66 with our OTA antenna.

Here is what we have done, and have yet to be successful:

Antenna > 15db booster > 200ft cable run > 40db booster > [2ch combiner, below]
Modulator ch. 66 (+60db) > 150ft cable run > [2ch combiner, below]

Both go into: >2 ch combiner (splitter) > 16 output-splitter (full)

• For all cabling, we are using RG6 quad shield 2ghz cable.
• Any outputs of the splitters that we are not using are terminated with 75-ohm terminators.
• I have heard of some discrepencies with ch. 66 overlapping into some new digital UHF channels. We have an agile modulator that ranges from 14-99 (with a few gaps).
• Agile Modulator: BlonderTongue AM-60-550.
• The 40db booster is variable gain and tilt controls, a Channel Vision CVT-40BID.
• We also have various Motorola 15db signal boosters that boost the signals for long cable runs across campus.
• We are located in Fort Worth, Texas

When connecting just the antenna to the splitter, we get great reception across the entire campus.
When connecting just the modulator to the splitter, we also get great reception.
When they are combined, we get no reception of any kind anywhere.

Mods: feel free to move this discussion elsewhere.

 

[boba]

CH66 may be part of your problem I would suggest a lower channel. I am in Grayson County and use CH66 for in house distribution, most of the time it is clear but it does show some interference coming in on the TV antenna. I believe channel 50 LP is the highest channel currently being used in Dallas so a channel in the low fifties maybe a better distribution channel.

The fact that OTA by itself works and CH66 by itself works suggests the problem is in your method of combining signals or balancing signal strengths. Can you describe exactly what happens to the combined signals. Channels 8/52 and 11 are VHF broadcast channels (8/9/11) and should pass without problems unless your amplifiers or combiners block VHF.

You might also check the agile modulator to be sure those are not cable frequencies instead of UHF. UHF only went up to CH69 before Digital Conversion now I believe it tops out at CH52 and frequencies above are available for other uses.