Good signal strength - low quality (HDHR5-4US)

[chuckles67]

I just had a my antenna moved from attic to my roof. (due to poor VHF reception in the attic). When the installer left last week I had a clear picture on VHF channels ABC and NBC. Today the quality has dropped and I'm seeing pixellation and dropouts on NBC (Ch12). I can call the installer tomorrow to check on the install. However I'm seeing a great signal strength, but low signal quality (see attached picture): https://photos.app.goo.gl/xR6NwV57ueS6DuF67. Any advice here?

[jasonl]

What do your numbers look like on KGO on channel 7 (the only other major VHF station in the Bay Area) and KKPX on channel 41 (the other full-power station on Mt. San Bruno)?

What is the make/model of the antenna and what zip code are you in?

[chuckles67]

Hi

Ch07 (KGO-ABC) is good: all green and stable.

Ch65 (KKPX-ION) is okay: green/yellow

Config_gui examples are here: https://photos.app.goo.gl/Si4NvKuudkVzrAkQA

Post code is 94070 (San Carlos near the 280): 16 miles to San Bruno; 22 miles to SF Sutro Towers. Antenna is a Clearstream 2V mounted on a pole attached to a chimney (installed by a professional): orientation looks correct using TV finder app.

I also bought a Winegard HD7694P antenna in my attic, bought to replace the Clearstream 2V's former location in the attic. That might be a better choice on the chimney pole?

Thanks!

[jasonl]

I'd rather have the HD7694p pointed toward Sutro and Mt. San Bruno, yes. Are you pointing the other one east at Monument Peak and Mt. Allison? Might as well use the C2V for that, and while you're at it, remove the rabbit ears since there's no VHF over there anyway.

[chuckles67]

Both antennas pointing to San Bruno/Sutro (attic is blocked to the east). I made a small adjustment tonight - moving the roof Clearstream 2V antenna anti-clockwise by about 5º, and NBC signal quality has improved - and is watchable. I'll see how this goes, and maybe try the Winegard on the roof later.
Thanks!

[jasonl]

You're not combining the two antennas are you? That's likely to result in a worse signal than just using one, as the signals will likely arrive out of phase and result in lower signal quality than using one on its own.

[chuckles67]

Not combinig the signals - instead each antenna has a unique HDHomeRun tuner (xxxx4-2US and xxxx5-4US). Repositioning the antenna has helped and NBC has been okay so far (though with signal quality for NBC on VHF hovering around mid-50s, I'm expecting weak signal problems in future: then I'll put the Winegard antenna on the roof and try that). Thanks Jason.

[jasonl]

The dipole on the C2V is sized for optimal performance on channel 7. It gets a bit worse as the frequency goes up, though I wouldn't expect it to fall off that much. The Winegard should do significantly better since it has more elements.

[chuckles67]

I swapped the roof-installed Clearstream 2-V (C2-V-CJM) antenna with the Winegard HD7694P: now all TV signals that I care about are green. Much better reception.

e.g.: NBC (11-1) went from signal quality SNQ of low-50s to mid-80s; ABC (7-1) went from signal quality SNQ of high-70s to 100. NBC used to occasionally pixelate, not any more.

Thank you for recommending the Winegard.