Need some TV antenna troubleshootin'

[toxcrusadr]

Mom's house in Albuquerque. Antennas are on a mountain 5000 ft higher than the city and we have line of sight about 12 miles. Except for a single layer of deciduous treetops down the block that we would need a much taller pole to get over. On windy days we can have trouble.

Current setup is a compact "HDTV" antenna bought at WalMart a couple years ago that's supposed to do it all (UHF/VHF), mounted on a pole about 10' above the roof. Works pretty well but we have reception problems with a couple channels, 7 and 16, especially on one TV. Both are broadcast on their nominal channels (no virtual channels on these) so one is the low end of 'high VHF' and the other is in the low UHF.

Maybe too many splitters. There's one at the antenna that runs one output down to the living room TV which is where the problem is (2009-ish Samsung). The other leg of the first splitter goes to a second splitter which feeds two bedrooms. One is not currently used and the other is where my sister stays, and she has a fairly new 24" Sansui that gets all channels.

So I figure the Samsung doesn't have a real good tuner. I've checked and replaced each leg of cable - in fact last year I found a 25 ft section that was bad, was not passing signal at all, and as soon as I replaced it we had TV. I put a Winegard preamp on the roof today (fed by power thru the line from a module inside) and it was worse than nothing, so I'm pretty sure this garage sale unit does not work at all. Just funny that the Sansui works fine downstream of 2 splitters but the Samsung doesn't get these channels after only one splitter.

I'll post a pic of the antenna, it was a $40+ unit supposed to work at 35 miles or something (no longer have the info on it).

Should I get a second antenna just for the Samsung or is there a better way?

BTW it's a stucco house lined with chicken wire for the stucco so indoor antennas don't do well.

 

[toxcrusadr]

Closeup of the antenna.


Looking from behind with the trees and mountain the background. The antennas for virtually all of our stations are right on top and it's pointed directly at them.

You'd think we would have all the signal we knew what to do with but not so much.

 

[Spe@kerBox]

One problem that I have seen is the possibility of overload. My antenna is amplified and I found I had to back off on the gain to prevent overload of the TV tuners. The YMMV.

 

[toxcrusadr]

I have a big old Yagi that we took down when we redid the roof and put up this one. I guess they are more for UHF, maybe it would help with Ch. 16 but I'd need a way to combine the signals from two antennas.

 

[toxcrusadr]

How does signal overload look? How do you know you have it?
Edit: We get about 20-30 channels fine, a few don't come in that are less important, so I don't think we have too much signal. Ch. 7 which sometimes pixellates is one of the big networks. 16 is PBS.

 

[WobblySam]

Mom's house in Albuquerque. Antennas are on a mountain 5000 ft higher than the city and we have line of sight about 12 miles. Except for a single layer of deciduous treetops down the block that we would need a much taller pole to get over. On windy days we can have trouble.

Current setup is a compact "HDTV" antenna bought at WalMart a couple years ago that's supposed to do it all (UHF/VHF), mounted on a pole about 10' above the roof. Works pretty well but we have reception problems with a couple channels, 7 and 16, especially on one TV. Both are broadcast on their nominal channels (no virtual channels on these) so one is the low end of 'high VHF' and the other is in the low UHF.

Maybe too many splitters. There's one at the antenna that runs one output down to the living room TV which is where the problem is (2009-ish Samsung). The other leg of the first splitter goes to a second splitter which feeds two bedrooms. One is not currently used and the other is where my sister stays, and she has a fairly new 24" Sansui that gets all channels.

So I figure the Samsung doesn't have a real good tuner. I've checked and replaced each leg of cable - in fact last year I found a 25 ft section that was bad, was not passing signal at all, and as soon as I replaced it we had TV. I put a Winegard preamp on the roof today (fed by power thru the line from a module inside) and it was worse than nothing, so I'm pretty sure this garage sale unit does not work at all. Just funny that the Sansui works fine downstream of 2 splitters but the Samsung doesn't get these channels after only one splitter.

I'll post a pic of the antenna, it was a $40+ unit supposed to work at 35 miles or something (no longer have the info on it).

Should I get a second antenna just for the Samsung or is there a better way?

BTW it's a stucco house lined with chicken wire for the stucco so indoor antennas don't do well.

To me the first thing that came to mind when you said "windy days" was multipath. Trees flopping back and forth are a good source of reflected signals arriving out of phase with each other. Older HDTV tuners were absolutely awful at dealing with multipath. I have a 10 year old Panasonic that doesn't do well on windy days, but a 1 year old Samsung that does much better.

Your antenna looks like it's basically a UHF corner reflector type with a single folded dipole for VHF. Not really a problem - should be fine.

A channel on "high VHF"? I know early on, some channels got special dispensation to remain on their original frequency, but I thought they had all moved now. All stations are on UHF (at least that's what I understood). UHF is far more susceptible to multipath than VHF. If you have a signal meter somewhere buried in the Samsung's setup menu, tune to the problem station, bring up the signal strength meter and watch it. Does it swing 10 percentage points or more? That's multipath.

Using amplifiers can be tricky. First, you have to have one for the right frequency range - noise, possible oscillation are problems with cheap ones. It should be mounted at the antenna for best results.
Terminate unused ports on the splitters (you do have high quality splitters, right?) with 75 Ohm terminations.

Good luck

 

[W9TR]

I’d run tvfool.com for your location to see if there is anything unique about 7 and 16 in terms of erp or azimuth. I’m assuming pretty much everything in ABQ is up on Sandia Crest.

Multi path is a huge deal in the mountains and a very directional antenna is helpful in reducing it, even though a dipole may work with some tv’s.

Preamps are a bad idea unless you are in deep fringe and even then they can be problematic.

Tom

 

[toxcrusadr]

Looks like I missed a couple informative posts here, thanks guys.

No idea what I meant by 'low end of high VHF'. ABQ is at 5000 ft so I blame temporary oxygen deprivation.

Multipath due to the trees combined with an older tuner makes a lot of sense. The Sansui that works better off the same antenna is newer.

I suppose we could add 20 ft to the mast....