Hi all,

I have a CM 4221 on my roof. It runs to a wiring closet (maybe 60 - 100 feet). I have a 2-way splitter there. The outputs go to two rooms, each another 60 - 100 feet away. One of the tuners is the built-in ATSC tuner on a small LCD TV, and the other is the tuner of an HR10-250.

The setup works pretty well, but we get dropouts fairly often (every other night, say). It's often enough that we TiVo our DirectTV SD channels rather than the OTA HD ones.

Should I add an amplifier into the system? Would the best solution be a 7777 up at the antenna with the power injector before the splitter - or should the amplifier be right at the splitter, or after the splitter? Also, I don't know to what extent the quality of the splitter matters for VHF/UHF, but I could buy a new one if necessary. Mine is an old one I found in my box of unused electronics : )

Thanks for the help!

Here's the info from antennaweb.org:

* yellow - uhf KKPX-DT 65.1 ION SAN JOSE CA 304° 20.8 41
* yellow - uhf KGO-DT 7.1 ABC SAN FRANCISCO CA 309° 25.0 24
* yellow - uhf KPIX-DT 5.1 CBS SAN FRANCISCO CA 309° 25.1 29
* yellow - uhf KQED-DT 9.1 PBS SAN FRANCISCO CA 309° 25.0 30
* yellow - vhf KNTV-DT 11.1 NBC SAN JOSE CA 303° 20.7 12
* green - uhf KSTS-DT 48.1 TEL SAN JOSE CA 66° 17.3 49
* green - uhf KTSF-DT 26.1 IND SAN FRANCISCO CA 304° 20.8 27
* green - uhf KMTP-DT 33.1 IND SAN FRANCISCO CA 309° 25.1 33
* green - uhf KRON-DT 4.1 MNT SAN FRANCISCO CA 309° 25.0 57
* green - uhf KBWB-DT 20.1 IND SAN FRANCISCO CA 309° 25.1 19
* green - uhf KTVU-DT 2.1 FOX OAKLAND CA 309° 25.0 56
* green - uhf KCNS-DT 38.1 SAH SAN FRANCISCO CA 309° 25.0 39
* green - uhf KICU-DT 36.1 IND SAN JOSE CA 69° 17.4 52
* green - uhf KCSM-DT 43.1 PBS SAN MATEO CA 309° 25.0 43
* red - uhf KTFK-DT 64.1 SAH STOCKTON CA 12° 32.4 62
* red - uhf KBCW-DT 44.1 CW SAN FRANCISCO CA 309° 25.1 45
* red - uhf KFSF-DT 66.1 TFA VALLEJO CA 309° 25.0 34
* red - uhf KTEH-DT 54.1 PBS SAN JOSE CA 69° 17.5 50
* red - uhf KDTV-DT 14.1 UNI SAN FRANCISCO CA 66° 17.3 51
* blue - uhf KSMS-DT 31.1 UNI MONTEREY CA 126° 36.7 31

In general, pre-amps work best installed as close to the antenna as possible, so the amp gets the strongest and cleanest signal at its input. Your situation is a classic case of a preamp requirement. Your CM4221, very likely, has the gain you need for reception at 25-35 miles but 120-200ft of cable attenuates the signal down to a point that your tuners cannot reliably receive it.

As for the splitters, a small investment in new splitters may help. If you make sure to use splitters that will pass DC, you can install the amp's DC power injector anywhere downstream. Use splitters that have as few a number of taps as you can get by with.

IMHO

Should I add an amplifier into the system? Would the best solution be a 7777 up at the antenna with the power injector before the splitter - or should the amplifier be right at the splitter, or after the splitter? Also, I don't know to what extent the quality of the splitter matters for VHF/UHF, but I could buy a new one if necessary. Mine is an old one I found in my box of unused electronics

A CM 7777 pre-amp would be a good choice. The CM 7777 has two antenna inputs: one for UHF/VHF or UHF, one for VHF only. KGO-DT ABC 7 will switch from UHF 24 to VHF 7 in 2009 after the analog shutdown. If the CM 4221 does not get KGO-DT then, you can add a upper VHF antenna to the setup through the CM 7777.

Yes, put the pre-amp at the antenna and put the power supply in the closet before the splitter. Do you have RG-6 coax? I agree that if you are using an old splitter of unknown quality, you should replace it with a good one, but only with 2 outputs.

Thanks afiggatt. Yes, I've got RG-6 throughout. I'll try a new splitter as well.