Suggestions for better HD reception

[Mazer]

I feel like I'm *this* close to getting this HTPC set up correctly and my curent stumbling block is HD reception.

When I built my house, I had the builder put in a coax cable from the attic to the basement (where my home theater is) and put in an electrical plug next to the cable so I could plan for a powered HD antenna.

I recently purchased the AverMedia 180 HD card and installed it into my system. The installation went fine, surprisingly.

Knowing that I wouldn't get great reception from the basement, I went to Amazon.com and bought a Zenith SilverSensor HD Antenna. I'd seen some good reviews on it. Unfortunately (buyer beware), I didn't realize that I was buying a refurbished unit from one of Amazon's distributors. The description said there were just some box dents but, as I found out when I got it, it was more than that!

I hooked it up to my system and....got nothing. Confused, I moved it into the attic and plugged it into the cable up there. The antenna promptly fell off the unit. As it turns out, someone had taken apart the unit because they had broken the connector from the coax plug to the antenna and, very crudely, soldered it back on but. When I pushed in the coax cable, it actually pushed the antenna out from the connector.

So, I took the antenna apart, resoldered the wires and put it back together. When I hooked it up, I was getting good reception (88+) on 3 of the 7 or 8 channels I'm interested in. I futzed with the position a bit but it seemed that every time I locked in one station, I'd lose another.

I decided to try a different antenna and went to Radio Shack to buy the DA-5200
powered antenna.

I connected it to a rafter in the attic, hooked up the cables and the power and ran through BTV setup again.

I found that I was getting several channels (NBC, Fox, some other local channels) very well (94+) but CBS and ABC were 33 to 55 on strength.

I tried some repositioning but that didn't help.

So, I've been to http://www.antennaweb.org and I'm oriented correctly.

Any other suggestions here? I feel like I'm so close to solving this part of the setup but I'm stuck at this a bit.

I think I got better reception on CBS with the Silver Sensor antenna. Should I try combining the signals?

[Harold]

Well the obvious one is an outside antenna, which you may not want. In the attic there is some signal attentuation (nails, possible metal in insulation, etc.) Shorter cable runs are better. A signal amplifier may make up some of the losses for a long cable run. Are all the stations on the same azimuth? Are they running similar transmitter power? This may account for the signal differences.

On the AVSForum, there are threads for OTA HDTV for most major US markets. In Houston, some of the TV station engineers respond to questions posted there.

I've had good luck with an eight bow-tie UHF outside antenna and I'm 35 miles from the transmitters. All the stations that I want are UHF, expect for PBS, but since it's VHF frequency is high enough, the UHF antenna works ok. It's probably the weakest signal that I get. I use the same card that you do.

[Zogg]

I have spent umpteen hours trying to improve my HD reception. In the process I've used 2 pre-amps, 2 amps, 2 antennas, multiple locations, climbed on the roof multiple times, and about ripped my hair out. I think it's now as good as it's going to get, which is pretty good but occasionally I get some glitches. Here are some tips:

1. Use antennaweb.org and other web sites or Google to determine if your stations are transmitting on UHF or VHF frequencies. I think a lot of people miss this. UHF and VHF use different frequency ranges, and if you need both, then you have to make sure that your antenna and pre-amp work on both.

2. Use a pre-amp at the antenna, and don't waste time with the ones they sell at Lowe's. Order a good Channel Master or similar model. There's a good comparison chart here and this is a good dealer IMO. Depending on how far from the towers you are, you may need a pretty strong pre-amp. I am 32 miles away, down in a hole, and using attic antennas so I got the strongest Winegard model after trying a less-strong Channel Master.

3. Assuming you will have to split the signal to multiple tuners, use an amplified splitter. Or run it through an amp (10dB for example) and then a regular non-amplified splitter.

4. Experiment some if you want to. I tried putting some reflective surfaces behind the antenna at different distances just to see if I could enhance things a bit. It did help some but was impractical so I didn't keep it.

I read in another forum that someone in frustration connected 2 antennas into a 2-1 splitter/combiner and then got a better signal. I did the same thing, running the output of the combiner into the pre-amp, and it WORKED! Turns out that one of my antennas is stronger on VHF, the other on UHF, so combining the two helped both bands. Most sources will tell you not to do this, but it's working for me so give it a go.

A friend recently declared getting good OTA reception to be Black Magic, and I totally agree. Good luck and I hope my experience will help you a bit.

Z

[Bloggator]

I ran into similar problems with my attic antenna here in Kingwood, TX (Northeast Houston). The antenna farm is about 45 miles away and I could either get NBC at 95-100% and everything else at about 65% or everything else at at 95-100% and NBC at 65%. Unfortunately, about half the shows we watch are on NBC, so I had to get a solution.

I took a Channel Master 4228 and a silver sensor and combined them with a Winegards CC-7870 2-Set Antenna Coupler. ($17.00 at affordablehdtv.com).

I pointed the 4228 at the main antenna farm and the silver sensor at the NBC coordinates (about 15 degrees west of the antenna farm), and now I get 95-100% on everything.

Hope that helps.

[btvfreak]

If you get cable service, then get a HDHomeRun. No more messing with antennas!

[nrf]

Are you still working at this? I have spent quite a bit of time in my own setup, and use antennaweb as a starting point. I happen to be about 29 miles from my target stations. I have chosen to use UHF only, which means I miss the one oddball station that has chosen to use VHF. I use a multiple-bowtie antenna in the attic, mounted to a pipe and flange so it doesn't move around. My roof is shingle over wood so no insulation to block it. I use a (radio shack ) antenna mounted amplifier where the power supply is downstairs and the amplifier in the attic. I then send the signal to my pvr location where I use an amplified splitter, one output goes to a tv in another room, and the second output to a 4-way splitter for my tuners. I get 100% on all 4 of them by the tuner-provided utility, not taking btv wizards' numbers seriously. I recommend using such a tuner wizard to guide your work, seeing if a change helps or hinders.

It is good to note that each foot of cable and each connection has a loss associated with it, and each antenna has a directional gain figure. If you find that a certain configuration gives you 18db at the tuner and you hope for 28, you could then predict that a stronger antenna or higher gain amplifier (or combination) can produce what you want. Also, remember that an amplifier at the antenna end of a long run of coax is far better than one at the tuner end.

good luck!

[ZetaVu]

I originally had an attic antenna and a roof mount antenna at my house, I assume the attic one came first since it was disconnected and the roof mount connected. I tried both and the attic lost considerably more signal than the roof. It has since been pulled. If you want a serious OTA signal mount on the roof, old fashioned arrow design properly pointed, use RG6 coax, minimize splits and add an amp if you need to boost signal.

[Flatus]

Just one minor thing to keep in mind when installing an attic antenna--grounding it just as one would ground an outside antenna.

I learned that lesson when lightning penetrated our tile roof in Panama, got into the antenna, and promptly zapped our brand new Sony TV.

Flatus

[flashc]

I am using an attic antenna setup. I use 2 channel master deep fringe antennas (I don't have the model numbers handy, but they are about 12 feet long). I ripped off the VHF sections and am just using the UHF boom and the reflector since no HD channels are in the VHF band in my area. One antenna is pointed towards DC/Northern Virginia, the other is pointed at Baltiimore. I summed the antennas together and use a moderate gain preamp to boost the signal down the coax to the TV rooms.

I borrowed a spectrum analyzer from work over a weekend and used it to fine tune the antenna pointing. I strived to maximize the signal strength and more importantly to equalize the signal power variations across UHF band in order to ensure that no signal was being emphasized at the expense of another. It's a bit tricky since antenna sidelobes can cause partial cancellation of signals.

After I did this, all the signals were within 10 dB of each other and there was no amplitude slope across each ATSC carrier.

It took about 2 hours to fine tune the pointing, and I lost about 5 pounds of sweat sitting up in the hot attic in July, but it was well worth the effort.

Unfortunately, a spectrum analyzer is not readily available for most people, but if you have access to one, then by all means use it to optimize your reception.

[remleym]

Actually, if you have a USB HDTV tuner, here's a useful tip for adjusing your attic antenna... Load the tuner software on a laptop and take the USB tuner and laptop with you into the attic. I have a DVICO USB Gold and this works very well with a laptop computer. Hook on to the antenna and tune in UHF and/or VHF analog signals (not digital). Orient the antenna for the strongest signals with the least ghosting. While digtal tuners will "clean up" the ugly snow and ghosts typically seen in analog TV, they are still impacted by the multipath problem. Too much multipath and even a relatively strong signal may not provide good digital tuner reception. By going after the best analog signal (where you can actually observe the signal quality for both strength and ghosts) you will also end up with the best signal for digital tuners. The transmitters are typically in the same location. The laptop into the attic is the lightest, easiest way to go. In the past I've actually taken a small 110v TV into the attic but that involves dragging extension cords and such up through a small attic access and spending extra time in the attic on a warm day isn't fun.

[Jakesty]

I remember hearing about someone who did something similar, but instead brought the laptop to the roof and with a wireless connection and VNC or PCAnywhere, connected to their HTPC to view the quality of the signal. I think your solution is easier.