I've now got a decent outdoor antenna (Winegard PR 9018 UHF) with the $35 Radio Shack preamp connected right at the antenna's matching transformer. See sig for more hardware details. I'm using R5A22.

I can tune two stations (one with one channel, one with two channels) fine (on-screen says 100%), and per antennaweb.org they're both about 5 miles away. I was even able to use one of those stations with a cheesy home-brew UHF loop on the roof, and it got fairly reliable when I added the preamp.

However I've been totally unsuccessful in tuning two other stations in the area, even with the new antenna. They are supposedly 15 miles away (and both in roughly the same direction as the two 5-mile-away stations, and where my antenna is pointed).

mythtv-setup's channel scan finds all these stations fine (and another that's farther away and nowhere near where the antenna is pointed), but things go black when I try either of the 15-mile stations.

The channels I can get have no special symbols.... just 381, 541, and 542, in the channel "name". The 15-milers I cannot get have underscores... 3_1, 3_2, 9_1, and 9_2. That's how I'm typing them (with underscores as necessary). If I leave out the underscores, it just stays on the current channel. Am I doing that right?

I know the drivers are picky about a primo signal to decode, but jeez, I've got 13 dBd of antenna, 10 db of preamp, and about 50 feet of good quad-shield RG6 to the HD-3000. I'd expect to get something from the 15-mile stations (both big network stations). Looking at the numbers again I could probably point the antenna a few degrees better, but still I'd expect something. I still think I'm within the half-power beamwidth of the antenna.

Any suggestions? What are the best tools to debug with? Signal-strength indicator other than the on-screen that pops up for a few seconds (but you never see if the channel doesn't get tuned)?

Laramie

_________________
Intel P4 3.2 GHz (with HT)
Intel D865GBF motherboard
pcHDTV HD-3000
GeForce FX 5200, 256 MB, AGP 8x
1 GB RAM
300 GB Seagate Barracuda hard drive
Antec Overture II case
Samsung LCD display (sadly 1280x1024 max)

The azap utility should give you an indication of signal strength. There's a nice post here that describes in pretty good detail how to use it. The post is meant to be for QAM tuning, but azap will work for OTA just as well.

http://mysettopbox.tv/phpBB2/viewtopic.php?t=8104

I should say that I've had problems getting azap to work with my Air2PC (mine always shows a 0000 signal strength even when I'm tuning channels in perfect clarity), but I think it's something specific to my card or my setup, since no one else seems to have any problem with it. Anyway, give it a try...

You also might want to include your location in your profile. Sometimes people in the same area may have tips/tricks for tuning hard to get stations.

I re-did a channel scan, which showed seven channels in my area (Columbus, GA). That's all the channels that antennaweb.org indicates I should be getting.

My default channel is 381. For a long time I thought that 381, 541, and 542 were the only channels I could get, because I was using the up/down arrow keys to change channels. From 381, up-arrow goes to 541. Up-arrow from there gets me 542. But up-arrow from there goes to a black screen, then after several minutes MythTV comes back with a message indicating the back-end has gone away.

I attribute this to the known issue with the HD-3000 freaking out on poor signals. (See signature below for my hardware list.)

However, after doing a new channel scan and writing down the channels it found, I can tune each and every one if I enter the channel number on the keyboard.

However, I still get the black screen (of death) when I try to use the arrows to change channels, in some cases. Quickest and easiest recovery is to shell in from another computer and reboot.

Channel 91 up-arrow gets me channel 92
92 ^ = 381
381 ^ = 541
541 ^ = 542
542 ^ = black screen of death

31 ^ = 32
32 ^ = black screen of death

Is it trying to go to some non-existant channels?

Here's a run-down of what I know of these channels:

381, 541 & 542: 4 miles away, antenna pointed within half-power beamwidth.
31, 32, 91, & 92: 15 miles away, antenna pointed directly.

Antenna is a Winegard PR-9018 barely above my roof peak. I live on something of a local high spot, so my view towards these stations is pretty good, aside from some trees in the way a few houses away. There's foliage on some of the trees right now, but not all. 381, 541, and 542 give solid reception. The others show occasional hits (pixelation), but are generally usable at the moment.

Laramie

_________________
Intel P4 3.2 GHz (with HT)
Intel D865GBF motherboard
pcHDTV HD-3000
GeForce FX 5200, 256 MB, AGP 8x
1 GB RAM
300 GB Seagate Barracuda hard drive
Antec Overture II case
Samsung LCD display (sadly 1280x1024 max)

I just installed R5B7. Sweet!

The channel-changing-on-up-arrow (or down arrow) problem has gone away.

It also seems to deal with weak channels much better, too.

Laramie

_________________
Intel P4 3.2 GHz (with HT)
Intel D865GBF motherboard
pcHDTV HD-3000
GeForce FX 5200, 256 MB, AGP 8x
1 GB RAM
300 GB Seagate Barracuda hard drive
Antec Overture II case
Samsung LCD display (sadly 1280x1024 max)