San Francisco, CA - OTA - Page 155

Did you do a re-scan??

KGO is back on Digital Ch 7 now

Indeed! And KRCB for that matter, which comes in here (Redwood City, Emerald Hills area) at 80 on my Dish ViP722.

Interestingly, on the spectrum analyzer, KQED and KRCB look very similar, nice flat spectrum, no dips or peaks, and similar strength. But KQED won't lock, whereas KRCB is rock solid.

I'm pretty sure the problem is multipath, probably reflections from the East Bay hills.

Peter

hi all,

I don't receive Fox (2.1) and MNT (4.1) ATSC OTA any more after yesterday.
NBC (11) and PBS(9) and CBS (5.1) and etc are Ok.

Any idea what is going on for the FOX?
Do you have it via OTA in San Jose?

tnx

Regarding certain stations not carrying HD programming. I'm sure plenty know this already. But the limiting factor with regards to KTEH is that they have 5 subchannels. There's no room for HD.

The following page says the different ways what's broadcast can be divided up:
http://en.wikipedia.org/wiki/Digital...considerations

Someone recently wondered about whether KPIX CBS 5 has additional subchannels besides just 5.1. No is the answer. But the following site makes it easy to determine that info:

http://rabbitears.info/ -> Listings ->

Or just a direct link:

San Francisco, California
http://www.rabbitears.info/market.php?mktid=6
click KPIX-TV
click "Technical Data and Screencaps" (as long as Javascript is enabled)
then scroll down a little.

Or indeed:

http://research.backchannelmedia.com...o-Oak-San_Jose

is useful too. Just ignore its .0 channels as those are the old analog ones.

I especially like this site when getting TV Guide On Screen (TVGOS) setup properly with the DTVPal in its special TV Guide mode where it converts digital TVGOS listings into analog for my Panasonic recorder.
This site uses the same call sign letters for the channels that the TVGOS system uses.

I talked more about that in the DTVPal thread. Here is a link to that.

In this message I pointed out that Backchannelmedia has the wrong info for AZASF. It lists 19.4 where it should be 20.4.

I'm getting KGO good now, and also KQED is clearer as well (drops out less). I use an indoor antenna and face north and I live in the San Francisco, but Sutro and Mt. San Bruno are to south, so the antenna faces almost 180 degrees the wrong way. I've been using a Winegard SS-3000 and sometimes I use my homebuilt mclapp antenna (search for it on this website). I may retire the homebuilt because its so big--I had been using it to pick up KNTV but may no longer need if the Winegard continues to receive KNTV well. KGO had worked before only with the rabbit ears and not at all with either the Winegard or the mclapp. The KGO move was good for me (and I was prepared to get VHF-hi because of my work to get KNTV).

One thing its been somewhat lighter winds in the afternoon (and may continue next week due to a cut-off low possibly being formed) so it'll be interesting when I try to watch the evening news during the windiest part of the day when the winds come back up a bit.

PS Also noticing that 44 and KCSM have more "Leroy Nieman painting" activity where the signal starts to be below the threshold than normal, to the point about the auxiliary antenna. 44 had usually been a very solid signal for me before.

I too am not receiving anything from KGO here in Fremont, using a terk HDTVa.
Everything else that I watch came in fine (ktvu, kron, kpix, kntv, ktsf, kicu....)

BTW how exactly are you suppose to adjust 2 vhf antenna thing? The uhf side is simple you just point to the station, but the vhf antenna is there some sort of optimal length and what angle should they be with respect to the station.... etc? I try to read some articles on adjusting them but quitely lost interest since it's so technical.

I am in San Jose, I am getting 2.2, 4.1 just fine. Just can not get 7.1-3 (KGO).
I have an outdoor antenna CM -4221.

Your CM4221 is a UHF antenna. KGO has now moved its digital transmission to physical channel 7, which is VHF low band. The CM4221 isn't going to work too well on that frequency.

Peter

Channel 7 is the lowest channel on the upper-VHF band. It is NOT on the low-VHF band.

- Trip

Ooops, thanks for the correction Trip.

Even so, I don't think the 4221 is going to work very well. The plots in the HDTV primer antenna comparisons show it has around -15dBi gain at channel 7.

http://www.hdtvprimer.com/ANTENNAS/GainVHFnetUHF.gif

Peter

Not showing up.. 2,5,7,11 etc all OK in San Jose


bob

Mike, did you rescan your TV or converter after Friday night? Both KTVU and KRON changed frequencies.

Also, are you getting KGO? They moved their digital transmission from channel 24 to channel 7. So you'd need to rescan to get them, too. I'd be curious to know whether that works, because some of us in the South Bay aren't getting KGO now that they're on VHF.


Patty

Is there a change in KGO? I've been getting no digital signal from D7-1 for more than a day. Using MyHD 120.

Oh, I see they're 7, not 24 anymore. Why did they have to change that?

anyone else with no channel 4 after rescan?


bob

I don't know the exact answer to your question. I think there's a best way to approach this problem and I recommend trying this technique if your hardware supports it.

And if you are aware of this technique, ignore the info. Maybe someone else can benefit from it.

The following are all potentially problematic channels. If you get them, of course they aren't a problem. But if you used to get them and now don't you could utilize the technique I'm going to mention.

For any of these that you are having trouble receiving the most important thing is to get your tuner to recognize that their VHF or UHF channel has changed. Your tuner is probably still looking for them at their old location.

If this means you move your antenna in such a way that you don't get other channels for a few minutes, so be it. Ideally your TV/recorder/converter-box has a way to keep the signal strength displayed as you manually try to tune into these channels. If not you'll have to keep blindly doing channel scans after each new attempt at a different antenna position.

The old way of moving the antenna until you see a picture on the screen won't work. Not unless your tuner lets you manually tune to individual channels.

I only have experience with the two converter boxes I have. I'd try doing a similar technique with other hardware.

Zenith DTT901 converter: menu button, Setup -> Manual Tuning

press up or down arrow until you get to 07.

Then move the antenna all over the place until you see the signal strength as strong as possible.

Then press the center button in the middle of the arrows to add the channel.


DTVPal converter: menu button, Setup -> System Setup -> Channel Setup -> Add a New Channel

enter 07 or press left or right arrow until you see 07.

Then move the antenna all over the place until you see the signal strength as strong as possible.

Then use the down arrow and press right arrow to change "scan: stopped" to "scan: started".


After you have gone through and gotten all of the channels to be recognized at their new VHF/UHF locations you can worry about the next issue of moving the antenna in such a way that you get as many channels that you care about at the same time. And if that's not possible you might need to get a better antenna. Or perhaps if you have just a UHF antenna combine it with a VHF antenna using one of those VHF/UHF combiners.

I was going to just mention the channels I receive. But then I decided to include all the ones that I saw as different between between a tvfool.com printout before the transition and one after. I wish rabbitears.info still showed the channel number changes that were going to take place. Or that I saved a copy of its info. As it is I had to play tennis with my eyeballs (back and forth, back and forth).

update1(
It just occurred to me that if your hardware lets you delete channels you could just delete these problematic channels. At least that will get around the tuner looking at the wrong VHF/UHF chan.

And then the next issue is that depending on the type of scan you do it might be that unseen channels are automatically removed anyway.

There are two different types of scans that I'm aware of:

1. Find currently available channels only and don't leave any channels that can't be seen.
2. Find new channels and add them to the existing list of known channels.

It is just the 2nd of these scans that will have a problem with leaving your tuner looking at the old VHF/UHF channel number. (if it doesn't see the channel at the time of the scan, of course).
)

update2(
Actually that last point isn't entirely true. My Zenith DTT901 converter box left the old 7.* in addition to adding the new 7.* when I used its "EZ Add" channel scanning method instead of "Auto Tuning".

The same thing happened for all of the 2.*, 4.*, 36.* channels.

When using the channel up and down buttons each of these channels was visited twice. First the one with the signal and then the one without.

A nuisance. Or something useful if you are able to get the same virtual channels from two different markets at the same time. (maybe using some powerful antennas)

The DTVPal converter box only kept the new instance of those channels.
)

The 4221 is very poor at channel 13 and gets even worse then that. A simple VHF-HI antenna is the best thing to add to that 4221. The AntennaCraft Y5-7-13 is only $23 plus shipping. And if you have an amp with separate VHF and UHF inputs, you could use that, or get a Pico Micro VHF-UHF joiner for $4. (alternate to the AntennaCraft Y5-7-13, is the Winegard YA-1713, it is a bit more expensive, but reports say that it is better built)

Oh yeah... analog tv is worthless now.

KRON is running at half power until they get the other half of their transmitter converted to channel 38. They say they should be back up at full power around June 18th.

Larry
SF

Not getting KGO 7 in south bay despite repeated rescans. Getting all other channels. Using kind of a cheesy philips "indoor/outdoor" antenna (situated outdoors) but I swear I used to get some kind of VHF with this rig previously. Tuner is samsung db-h260f . It shows zero bars of signal strength if I try to manally tune "7" .

Even if this is all "user error" on my part, I think we've heard enough reports of people losing KGO to conclude they made a risky decision to go for VHF and I am beginning to think that risk did not work out too well for them. Basically they have gone dark for quite a few of us. Maybe they'll come back to life in October...

Hi,

I have KGO on new 7 just fine - I use old RadioShack antenna that can get both U and V

I use my PC to get OTA via BTV - so rescan was not easy for me, but I did it and corrected physical MAJOR channels # and get my DVR back.

No I don't have channel 4 any more - to where it was moved? Not sure I watch this channel 4 much ...

So, VHF is still alive?? Dumb me told everyone all the new channels were UHF only!


bob

You cannot manually tune in a channel with the Samsung H260F. The manual for the Samsung says you can "add channels that were not memorized" but it's a bogus statement. If the box didn't find the channel during a scan, you will never be able to add the channel. Only a full scan adds channels.

Has anyone had any luck getting channel 32 after the digital switch over? I tried a few times over the weekend with rescans and repositioning of my antennas for both of my televisions and haven't had any luck finding that channel again.

I have a spectrum analyzer too and I've found it difficult to see the multipath on the display. You can have a flat signal but still have too much multipath. The multipath shows up as higher noise or ripple across the signal, not necessarily any pronounced dips or obvious ripple, although that can happen too.

Here are two images I took with the spectrum analyzer set to 2dB/division. The first is of KCRA on RF 35 with my Sony showing the Signal-to-Noise Ratio as 22 dB. Notice the ripple across the channel. The next is KXTV on RF 61. There are variations but much less. The fact that the signals are not flat seems to have little impact on the SNR. Both signals are strong enough that their SNRs should be 30 dB +.

I have a notch filter on channel 19 so KUVS on 18 shows about 20 dB less signal at the top end than at the low end yet its SNR is 31 dB, just a great number, showing that signal variation across the channel doesn't necessarily impact the SNR. The main culprit is multipath.

Chuck

i wondered about that. i'll experiment with some better antennas etc and hope the samsung picks it up via its regular scanning method eventually.

Chuck, thanks for those screenshots, very interesting. You got me thinking about why the multipath isn't easily visible.

I suspect that the problem is that for delays significantly longer than 1/(resolution bandwidth), the peaks and nulls will merge together.

For example, if I'm getting KQED reflections from the East Bay hills, we're talking of hundreds of us delay, and null spacings of just a few kHz. This will give a flat(ish) spectrum display, but of course the 8VSB equalizer won't handle such a long delay.

I'm attaching some of the screenshots I made. Very similar to your results, after taking into account different analyzer settings. This was with a 91xg antenna.

KRCB true heading:
http://www.petercripps.com/OTA_TV_sp...ue-heading.jpg
KQED true heading:
http://www.petercripps.com/OTA_TV_sp...ue-heading.jpg
KQED East bay bounce:
http://www.petercripps.com/OTA_TV_sp...bay-bounce.jpg

Peter

Peter,

Oh yeah, those KQED shots are ugly! No wonder it doesn't work. And the East Bay reflection is actually stronger. Reflections are almost always useless.

You might be able to make it work with a pair of 91XGs. I started here with a medium sized Winegard UHF antenna and the multipath was too bad to receive most of the stations, maybe 50% reception. I took a chance on a pair of 91XGs and that made a huge improvement, up around 99% of the time taking all the stations into account.

With multipath the most important thing is as clean of a pattern as possible.

That analyzer display looks very familiar. An HP-8566 or 68 by chance? I worked with those for years.

Chuck

Yes. Have a DirecTV HD Tivo with built-in OTA tuner and rescanned several times with this. It also allows you to test signal strength on each frequency manually and I get no signal on 7 with the ChannelMaster 4228.

Also have a DTV HR20-700 with OTA tuner built-in and same thing...cannot get KGO.

Prior to the switchover KGO came in perfectly and never had any problems with this channel.

On my 4228 setup in my location, D07 is actually a tad stronger than D24 was. Perhaps because I don't have LOS to Sutro and VHF diffracts over the hilltops a bit better than UHF does.

Just looking over the threads the past few days, it's apparent that those of us in the South Bay with UHF-only antennas are missing KGO. I have two questions that I'd like answered:

1) Those of you in the South Bay (San Jose, Sunnyvale, Fremont areas) that are getting KGO, which UHF/VHF antenna are you using (is there a good all-in-one long range solution)? And how far are you away from Sutro?

2) Is there any possibility that KGO made the wrong decision about staying in the VHF band and will switch channels if enough users complain? I'm not certain of all the upgrades planned for KGO, but is the power going to change after these upgrades? I can wait if that's the case. Otherwise, I'll shop for a good long-range VHF/UHF combo antenna and part ways with the C4.

My C4 antenna supposedly picks up the high-band VHF signals, but I get nothing for KGO, and 85-100% on all the other UHF channels.