Preamp Recommendations

[ducksoup18]

Hey all,

Im having a hard time getting Fox or any VHF reception at my house. I have a ChannelMaster CM-4221HD in my attic (about 15' up) and i can get a bunch of channels but the VHF channels come in sometimes and are completely out at other times. I have the antenna running about 10' to a splitter (i know, i know. its terrible, but once i get some info from the smart guys i'll be good), then to a HDHomeRun which my HTPC uses. I've tried connecting directly to the coax but that doesnt seem to help either. On the other side of my splitter i have about 30' of coax directly to a tv and that got Fox no problem for a while, but now its dead and wont even pick up a signal. I included my signal info below. Any help would be great!

Thanks,
DS18

http://www.tvfool.com/?option=com_wr...60b512e02dbb51

[Tower Guy]

Originally Posted by ducksoup18

I have a ChannelMaster CM-4221HD in my attic (about 15' up) and i can get a bunch of channels but the VHF channels come in sometimes and are completely out at other times. Any help would be great!

I'd add a Y5-7-13 VHF only antenna with a UVSJ.

http://www.solidsignal.com/pview.asp...aCraft_Y5-7-13
http://www.solidsignal.com/pview.asp...nna-%28UVSJ%29

[ducksoup18]

Thanks for the reply Tower Guy. Are there any other solutions that might be easier? I might not have room in my attic for another antenna. If i did do this, would I have both antennas up there with each of their lines going to the UVSJ (combining the signals) and then that would run down to my tuner? I was hoping to just add a preamp to hopefully bolster the signal.

Thanks again,
DS18

[GroundUrMast]

You could replace the existing antenna with a UHF/VHF combo antenna such as the Winegard HD7694P or any of its' larger variants (7695 through 7698).

An amplifier is not an antenna. To use an analogy, an antenna and well are similar in the way an amplifier and pump are similar. A well has to be dug deep enough to reach clean water. A high pressure pump at the bottom of a hole with a little muddy water can only deliver high pressure mud to the tap. Your CM4221HD is not designed to block real channels 2 through 13, but it's is not designed to receive them either. The CM4221HD is designed to receive real channels 14 and higher.. An antenna such as the HD769x series is designed to receive real channels 7 through 69.

I also run several HDHRs. They are the most critical tuners in the house... If they like a signal, all the other tuners in the house are happy with the signal. Do you have the HDHomeRun Config (GUI) utility installed? ("C:\Program Files\Silicondust\HDHomeRun\hdhomerun_config_gui.exe" on my PC.) It gives you the ability to monitor both the strength and quality of a signal.

http://forum.tvfool.com/showthread.php?t=820

[Tower Guy]

Originally Posted by ducksoup18

I was hoping to just add a preamp to hopefully bolster the signal.

It's not a signal strength problem, it's a signal quality problem. The 4221HD is not a VHF antenna.

The Y5-7-13 is the smallest high VHF (7-13) antenna available.

[ducksoup18]

Thanks everyone. One final weird thing. Channel 11 (NBC) is VHF and it comes in clear as a bell. Does this just mean that its a stronger signal from the tower and since my antenna is picking it up im lucky? Also, the non-hd Fox channel (9-2) comes in fine. Is this also the same deal? Sorry for the newb questions here fellas.

Thanks again,
DS18

[MisterMe]

Originally Posted by ducksoup18

Thanks everyone. One final weird thing. Channel 11 (NBC) is VHF and it comes in clear as a bell. Does this just mean that its a stronger signal from the tower and since my antenna is picking it up im lucky? ...

Your TV Fool radar plot clearly shows that KARE (NBC) is your strongest station with KMSP (FOX) the second strongest. It should not surprise you that your experience confirms TV Fool's calculations.

[ducksoup18]

Thanks for the reply. So if FOX is the 2nd strongest signal, how come my antenna isnt picking it up? Because its a VHF signal? Does this just mean that NBC is a fluke or something?

[John Candle]

Attics are unpredictable mostly poor reception locations. I recommend a Winegard HD7696P antenna mounted Above The Roof , aimed at about 357 degree magnetic compass.

[GroundUrMast]

Originally Posted by ducksoup18

Thanks for the reply. So if FOX is the 2nd strongest signal, how come my antenna isnt picking it up? Because its a VHF signal? Does this just mean that NBC is a fluke or something?

To say the same thing a different way; The CM-4221HD is good at receiving UHF signals but not good at receiving VHF signals. I suspect the NBC signal on real channel 11 is stable because it's stronger, and, the CM-4221HD is a little better at that frequency (by chance, not design). The Fox signal on real channel 9 is a bit weaker and I suspect, the CM-4221HD performance at the frequency range of channel 9 is worse (no surprise, it was never intended to perform well at that frequency).

Finally, as others have mentioned, attics are not the best location for an antenna. If you want better reception, mount the antenna where it has higher quality signal to work with.

[Tower Guy]

Originally Posted by GroundUrMast

I suspect, the CM-4221HD performance at the frequency range of channel 9 is worse

The old 4221 has negative 14 db gain on channel 9. Channel 11 is only minus 8 db.

http://www.hdtvprimer.com/ANTENNAS/comparing.html