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solarbirdSo we had bad weather last night - the always-weak channel 46 was breaking up badly, and we had some glitching even on better UHF stations - and I went up to make some more antenna adjustments to try and cope with it.
I tried enlarging the reflector on the VHF antenna, but got absolutely nowhere with that. Surprised me quite a bit, since I know reflectors work fine with VHF, but - not here, not for us, not for 46. RF is weird.
But I did find that I hadn't properly tightened down one of the VHF antenna's alignment bars! It was completely loose and free-swinging! I just missed it somehow. That can matter kind of a lot of it goes off-axis, and it's not hard for that to happen if it's free-swinging, even in an attic.
So I fixed that, and while I was at it, I moved the whole rig a little further forward, which put it in near-exact alignment with the low-power VHF pickup on the mostly-UHF antenna. In theory, that should put them into slightly better phase. It was already close, but this would be better.
It shouldn't be enough phase adjustment to matter, but between all three of these things, 46 got a lot more stable. I think it was mostly the loose alignment bar? But maybe it all helped.
I also found out that since I now have this big reflector on the UHF antenna, I could rotate it a bit off-axis for the KBTC reflection off Tiger Mountain without losing enough signal to care about, which put it closer to on-axis for the main Seattle UHF stations. Doing this really firmed up KING 5, which was showing bad behaviour in the heavy weather.
It's still a compromise point, but having the reflector let me set a much better compromise point for reception in bad conditions.
And after doing all that, and seeing that everything seemed to be working, I was still curious about why I get exactly zero sign of signal from VHF 6 on Queen Anne Hill in Seattle. The data I'd seen said it was aimed southeast instead of us, and low power. But all the broadcast television antenna sites thought I should see some indicator of signal, even if not enough to pick the station up properly.
But instead, there's no signal at all, which made me want to dig. So I went looking online at transmitter data and stumbled across something I didn't know, which is:
Channel 46 is also a low-power station.
It has only a single low-power transmitter, and it isn't even throwing peak power towards us, though it is throwing some. Given that reality, it's kind of amazing we're getting it at all. We have between 400 and 1000 watts aimed in our direction, depending upon your source. With hills in between.
And we get it anyway.
What we're seeing is basically a single old-style streetlight's worth of power... from across the county.
And it's a big county.
We even get it well most of the time. After I tightened down that one antenna director and made those other little changes, we even got it watchably during the tail end of heavy weather!
And that means this VHF antenna which I already knew was pretty good is in fact even better than I thought. Well done, Stellar Labs design team! Nice antenna!
But there's still no sign of 6. So I asked someone I know in the U. District about whether they got a channel 6, and they do not; they have no picture at all on that channel, just static. And they really should... depending.
VHF 6, while low power, shows two transmitter configurations in the database: one pointed southeast ("cardoid" configuration), and a second pointed both northeast and southwest ("figure eight" configuration).
At the same time, some of the sites say the station has gone dark.
If it's the former configuration, them not seeing it in the U. District makes some sense. If it's the latter configuration, it makes no sense, and the station has to have gone dark.
So my hypothesis today is that Channel 6 either really did have two transmitters and are currently only using the one pointed southeast, or, that they just have one and changed their transmitter configuration from a northeast/southwest paired configuration to a single stronger southeast-only configuration.
A southeast cardioid configuration would cover less territory, but a lot more people, which is what matters. And it explains a lot of what we're seeing here.
If my changeover hypothesis is correct, then for a lot of people, Low Power Channel 6 really did go dark. And at the same time, for a lot of other people, the signal got a lot stronger - or they just plain got a new station they hadn't previously seen. And that basically fits the observations on my end.
That's my hypothesis, anyway. I think it's pretty solid.
Incidentally, I also discovered that Channel 10 (low power, full-time shopping network) appears to have gone dark between when I started all this nonsense a few weeks ago and now. It's disappeared from multiple transmitter listings too, so I think may actually be done. I don't care either way - I blocked it when it showed up - but it would explain why it vanished. It's just funny that we had it one week and then didn't have it at all.
Which puts us to kind of a summary point, I think!
We're in a pretty good position now.
We get 54 channels, some of which I block because they're bullshit.
There are two low-power transmitters believed operating in Seattle that we don't get, neither of which I think aim at us, both of which show zero signal with a meter, one being the previously-discussed Channel 6, the other being a full-time Seventh Day Adventist religious station with a literally 250 watt transmitter and call letters containing numbers that I'm pretty sure also doesn't aim at us but fuck 'em, who cares, I haven't looked it up and we see no signal anyway.
Every station we get at all, we actually get well, either all the time, or in the case of 46, all but in very bad weather. Very stable signal levels across all times of day (so far) and across just about all conditions.
If we get it at all, we get it well.
Except for 46, which is a fair-weather station. And given how low power it is - 400 to 1000 watts vs. KING 5's megawatt) - I'm just fine with that.
Maybe it's growing up with cable, but in my head, this is how it should be. We get it, or we don't. None of this picture-going-in-and-out bullshit (with the exception of the hobby station 46, which is kind of how I categorise it so it's different) - a channel is either there, or it's not.
And - at least for the purposes of this project - that's how I like it.
I tried enlarging the reflector on the VHF antenna, but got absolutely nowhere with that. Surprised me quite a bit, since I know reflectors work fine with VHF, but - not here, not for us, not for 46. RF is weird.
But I did find that I hadn't properly tightened down one of the VHF antenna's alignment bars! It was completely loose and free-swinging! I just missed it somehow. That can matter kind of a lot of it goes off-axis, and it's not hard for that to happen if it's free-swinging, even in an attic.
So I fixed that, and while I was at it, I moved the whole rig a little further forward, which put it in near-exact alignment with the low-power VHF pickup on the mostly-UHF antenna. In theory, that should put them into slightly better phase. It was already close, but this would be better.
It shouldn't be enough phase adjustment to matter, but between all three of these things, 46 got a lot more stable. I think it was mostly the loose alignment bar? But maybe it all helped.
I also found out that since I now have this big reflector on the UHF antenna, I could rotate it a bit off-axis for the KBTC reflection off Tiger Mountain without losing enough signal to care about, which put it closer to on-axis for the main Seattle UHF stations. Doing this really firmed up KING 5, which was showing bad behaviour in the heavy weather.
It's still a compromise point, but having the reflector let me set a much better compromise point for reception in bad conditions.
And after doing all that, and seeing that everything seemed to be working, I was still curious about why I get exactly zero sign of signal from VHF 6 on Queen Anne Hill in Seattle. The data I'd seen said it was aimed southeast instead of us, and low power. But all the broadcast television antenna sites thought I should see some indicator of signal, even if not enough to pick the station up properly.
But instead, there's no signal at all, which made me want to dig. So I went looking online at transmitter data and stumbled across something I didn't know, which is:
Channel 46 is also a low-power station.
It has only a single low-power transmitter, and it isn't even throwing peak power towards us, though it is throwing some. Given that reality, it's kind of amazing we're getting it at all. We have between 400 and 1000 watts aimed in our direction, depending upon your source. With hills in between.
And we get it anyway.
What we're seeing is basically a single old-style streetlight's worth of power... from across the county.
And it's a big county.
We even get it well most of the time. After I tightened down that one antenna director and made those other little changes, we even got it watchably during the tail end of heavy weather!
And that means this VHF antenna which I already knew was pretty good is in fact even better than I thought. Well done, Stellar Labs design team! Nice antenna!
But there's still no sign of 6. So I asked someone I know in the U. District about whether they got a channel 6, and they do not; they have no picture at all on that channel, just static. And they really should... depending.
VHF 6, while low power, shows two transmitter configurations in the database: one pointed southeast ("cardoid" configuration), and a second pointed both northeast and southwest ("figure eight" configuration).
At the same time, some of the sites say the station has gone dark.
If it's the former configuration, them not seeing it in the U. District makes some sense. If it's the latter configuration, it makes no sense, and the station has to have gone dark.
So my hypothesis today is that Channel 6 either really did have two transmitters and are currently only using the one pointed southeast, or, that they just have one and changed their transmitter configuration from a northeast/southwest paired configuration to a single stronger southeast-only configuration.
A southeast cardioid configuration would cover less territory, but a lot more people, which is what matters. And it explains a lot of what we're seeing here.
If my changeover hypothesis is correct, then for a lot of people, Low Power Channel 6 really did go dark. And at the same time, for a lot of other people, the signal got a lot stronger - or they just plain got a new station they hadn't previously seen. And that basically fits the observations on my end.
That's my hypothesis, anyway. I think it's pretty solid.
Incidentally, I also discovered that Channel 10 (low power, full-time shopping network) appears to have gone dark between when I started all this nonsense a few weeks ago and now. It's disappeared from multiple transmitter listings too, so I think may actually be done. I don't care either way - I blocked it when it showed up - but it would explain why it vanished. It's just funny that we had it one week and then didn't have it at all.
Which puts us to kind of a summary point, I think!
We're in a pretty good position now.
We get 54 channels, some of which I block because they're bullshit.
There are two low-power transmitters believed operating in Seattle that we don't get, neither of which I think aim at us, both of which show zero signal with a meter, one being the previously-discussed Channel 6, the other being a full-time Seventh Day Adventist religious station with a literally 250 watt transmitter and call letters containing numbers that I'm pretty sure also doesn't aim at us but fuck 'em, who cares, I haven't looked it up and we see no signal anyway.
Every station we get at all, we actually get well, either all the time, or in the case of 46, all but in very bad weather. Very stable signal levels across all times of day (so far) and across just about all conditions.
If we get it at all, we get it well.
Except for 46, which is a fair-weather station. And given how low power it is - 400 to 1000 watts vs. KING 5's megawatt) - I'm just fine with that.
Maybe it's growing up with cable, but in my head, this is how it should be. We get it, or we don't. None of this picture-going-in-and-out bullshit (with the exception of the hobby station 46, which is kind of how I categorise it so it's different) - a channel is either there, or it's not.
And - at least for the purposes of this project - that's how I like it.
no subject
Date: 2021-12-24 04:50 pm (UTC)Not sure if I prefer the analog "get gradually worse" behaviour or not.
no subject
Date: 2021-12-24 06:14 pm (UTC)Basically all this is about a combination of minimising fluctuations as much as I can from this end, but also having a high enough base signal level that the fluctuations - say, a more reasonable 15-point transient drop - don’t cause picture corruption and sound drop-outs.
Even the most stable stations where I am have 10-point fluctuations regularly even in good weather, and if that fluctuation drops signal below 48 or so, you get glitching and sound drops when it happens. So I need normal signals in the 60s or better to get continuously solid results. Higher is better for more adventurous weather, obviously, but we need a decently big buffer in strength even in calm days.
The standard is called ATSC, by the way. ATSC3 is being rolled out slowly and will help some in that it’s better at multiphasic signal interference (of which we have a lot thanks to all our mountains) but most channels don’t do it yet and you need an ATSC3-aware tuner and we don’t have that.
no subject
Date: 2021-12-24 08:50 pm (UTC)At least once, we had issues because a cherry tree that had not been a problem when the antenna pair had been set up ended up growing enough to have a LOT of leaves solidly in the beam path. Only time when windy weather actually improved the situation that I have seen. Once diagnosed, a tree surgeon was dispatched.
no subject
Date: 2021-12-24 10:11 pm (UTC)