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post #10381 of 10402 Old 02-05-2015, 09:28 AM
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Just a report back, I haven't raised my antenna yet, that is in the cards for this weekend if we get a break in the rain but the CM DVR+ arrived yesterday and I gave it a whirl. 64 channels are coming in on it and so far everything works fantastic.

Scott
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post #10382 of 10402 Old 02-05-2015, 11:51 AM
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Originally Posted by Calaveras View Post
What is your antenna and rotor?

When you watch San Francisco stations are you pointed at SF (206°)?

Chuck
Antennas Direct 91xg, Eagle Aspen Rotr 100. I had to hose clamp some plastic pipe to the antenna and strung some rope over them to make it harder for the turkey vultures to land on it. They broke off all the elements on a big CM I had up there.

With the DVR, most of the SF stations disappeared, but currently watching KTVU, 2 out of Oakland, and I have a perfect picture and no dropouts. This with the antenna aimed due north.

Cranked it around to 206 and did a re-scan; still can't get 4,5,7,9,11 which are all the SF stations. Still getting the Sac Valley stations about as well as aimed north. This don't make sense, does it?
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post #10383 of 10402 Old 02-05-2015, 03:50 PM
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Originally Posted by Dee Barvo View Post
Antennas Direct 91xg, Eagle Aspen Rotr 100. I had to hose clamp some plastic pipe to the antenna and strung some rope over them to make it harder for the turkey vultures to land on it. They broke off all the elements on a big CM I had up there.

With the DVR, most of the SF stations disappeared, but currently watching KTVU, 2 out of Oakland, and I have a perfect picture and no dropouts. This with the antenna aimed due north.

Cranked it around to 206 and did a re-scan; still can't get 4,5,7,9,11 which are all the SF stations. Still getting the Sac Valley stations about as well as aimed north. This don't make sense, does it?

One problem is that the 91XG is a UHF only antenna. If you do manage to receive any VHF stations on it (KVIE, KXTV, KGO, KNTV) it will have to be pointed in some other direction since the antenna pattern is very screwy on VHF. I would seriously recommend adding a VHF antenna.

I have to ask this really obvious question..... Is the antenna really pointed in the direction the rotor box says it is? These inexpensive rotors get of sync all the time and you have to resynch the control box with the rotor.

If the antenna is pointed correctly then there's some other serious problem. It should be easy to receive the SF stations based on your TV Report. Since it sounds like you're not receiving them this confirms there is a major problem. It's really hard to troubleshoot this in a forum setting. One problem could be that only one side of the coax is connected to the antenna. I think that would mess up the directionality of the antenna.

I'm not keen at all on adding plastic and rope to the 91XG. That could be messing things up. I would think Turkey Vultures would have a hard time sitting on a 91XG with all those thin sharp elements. Some hams with bird problems have a life size plastic owl mounted on top of the mast to scare away birds.

Apparently you previously had a Channel Master antenna. Did it exhibit this strange pointing behavior?

Chuck
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post #10384 of 10402 Old 02-05-2015, 09:21 PM
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Originally Posted by Calaveras View Post
One problem is that the 91XG is a UHF only antenna. If you do manage to receive any VHF stations on it (KVIE, KXTV, KGO, KNTV) it will have to be pointed in some other direction since the antenna pattern is very screwy on VHF. I would seriously recommend adding a VHF antenna.

I have to ask this really obvious question..... Is the antenna really pointed in the direction the rotor box says it is? These inexpensive rotors get of sync all the time and you have to resynch the control box with the rotor.

If the antenna is pointed correctly then there's some other serious problem. It should be easy to receive the SF stations based on your TV Report. Since it sounds like you're not receiving them this confirms there is a major problem. It's really hard to troubleshoot this in a forum setting. One problem could be that only one side of the coax is connected to the antenna. I think that would mess up the directionality of the antenna.

I'm not keen at all on adding plastic and rope to the 91XG. That could be messing things up. I would think Turkey Vultures would have a hard time sitting on a 91XG with all those thin sharp elements. Some hams with bird problems have a life size plastic owl mounted on top of the mast to scare away birds.

Apparently you previously had a Channel Master antenna. Did it exhibit this strange pointing behavior?

Chuck
As far as I know, 7 is the only channel that still is VHF; at least that's what I was seeing during the digital transition. Everybody else went to UHF, so that's why I got the UHF only piece.

I built the house with the ridgeline on the roof exactly north to south, and the boom is parallel to the ridge when it's showing 360 on the rotor.

The vultures have knocked the corner reflector off twice, and managed to twist the aluminum elements as well. I've had up to 100 vultures circling my property if the thermal updraft was working. The section of rope and a couple bits of plastic pipe seemed appropriate to keep them from landing. I didn't have the owl...but that sounds more aesthetic.

I really didn't notice any issues with the CM as far as pointing it and getting a signal. 20 years ago, no web, so no way to know where the station was transmitting from. But I got all the stations that were in the Valley or the Bay Area that I thought were around. I even got 8 out of Salinas on a regular basis.

It is interesting how sensitive tuners are; the best was the CM digital analog conversion box. Sony 32" CRT from 2005 wasn't as good, about 75% of the CM box. Pany Plasma must have been built with a sat or cable input in mind, because the OTA tuner is pathetic compared to the first two. And the CM DVR is the worse of all....

Is there any link to diagnose an antenna installation that you know? I'm pretty handy, and if I can read something to try to work out what's wrong, that might be quicker.

TIA, Dee
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post #10385 of 10402 Old 02-05-2015, 11:23 PM
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Originally Posted by Dee Barvo View Post
As far as I know, 7 is the only channel that still is VHF; at least that's what I was seeing during the digital transition. Everybody else went to UHF, so that's why I got the UHF only piece.

I built the house with the ridgeline on the roof exactly north to south, and the boom is parallel to the ridge when it's showing 360 on the rotor.

The vultures have knocked the corner reflector off twice, and managed to twist the aluminum elements as well. I've had up to 100 vultures circling my property if the thermal updraft was working. The section of rope and a couple bits of plastic pipe seemed appropriate to keep them from landing. I didn't have the owl...but that sounds more aesthetic.

I really didn't notice any issues with the CM as far as pointing it and getting a signal. 20 years ago, no web, so no way to know where the station was transmitting from. But I got all the stations that were in the Valley or the Bay Area that I thought were around. I even got 8 out of Salinas on a regular basis.

It is interesting how sensitive tuners are; the best was the CM digital analog conversion box. Sony 32" CRT from 2005 wasn't as good, about 75% of the CM box. Pany Plasma must have been built with a sat or cable input in mind, because the OTA tuner is pathetic compared to the first two. And the CM DVR is the worse of all....

Is there any link to diagnose an antenna installation that you know? I'm pretty handy, and if I can read something to try to work out what's wrong, that might be quicker.

TIA, Dee

Look at "Real" column on you TV Fool report and that is the RF channel number. KVIE is on 9 and KXTV is on 10. KSBW is still on 8 and KNTV is on 12 and KGO is on 7. I think you need a real VHF antenna. The only VHF channel you wouldn't be able to get is RF 11 and that's KNSO virtual 51 in Fresno.

I'm not surprised that a 2005 TV didn't have a very good tuner in it. They all should be pretty decent now. I don't know anything about the CM DVR. I've had 6 different tuners here over the last 7 years. I had the Dish DTVPal DVR and its tuner was decent. I now have the TiVo Roamio Basic DVR. Its tuner is essentially identical to the my Sony TV and my 7" portable MyGoTV. The only bad tuner I've had was the OTA tuner in a Dish VIP622 DVR.

Assuming you had decent pictures on the analog stations (little snow and minimal ghosting) you should be able to receive all the digital equivalents. It sounds like you receive fewer stations now.

There's no link I know of to diagnose this problem. The 91XG is about the most directional antenna you're going to find so having it point in the wrong direction says something is wrong. I'd take it down and inspect everything. If you have an ohmmeter you can check cables for opens and shorts. You can take the plastic housing apart on the 91XG and inspect that. I'm going to guess that you have an older 91XG that uses a standard 300:75 ohm ferrite balun. The newer 91XGs use a printed wire board balun which is very poor on VHF. The older balun will pass some signal on VHF.

Chuck
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post #10386 of 10402 Old 02-06-2015, 10:20 AM
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Originally Posted by Dee Barvo View Post
With the DVR, most of the SF stations disappeared, but currently watching KTVU, 2 out of Oakland, and I have a perfect picture and no dropouts. This with the antenna aimed due north.

I performed a simple test inside the house to check my theory that the antenna pattern would be messed up if only one side of the coax was connected.

I set up a signal generator on UHF with a dipole as the transmitting antenna in a bedroom at the end of a hall that I could see in the kitchen 30' away. This reduced the reflections that could reach the receiver since the signal had to pass through a doorway. I used my little 8 element UHF LPDA as the receive antenna connected to my spectrum analyzer so I could measure the signal strength. I verified a normal antenna pattern with coax connected to the antenna. IOW the strongest signal occurred with the antenna pointing at the transmitter.

Then I connected a piece of coax that only had the center conductor making contact. The shield was open. The antenna pattern was completely changed and the signal was about 20 dB weaker. The weakest signal was when I was almost pointed at the transmitter. The strongest signal was when the antenna was off-pointed about 45°.

Since the 91XG is a different design than my LPDA, it would not be unexpected that the pattern with only half the coax connected would be much different.

My best educated guess is that you have an open connection somewhere in your system. It could be the cable. It could be the antenna balun.

Your symptoms fit the test results; best signals with the antenna off-pointed from the transmitters and weaker stations are not receivable. Also this would explain VHF reception. The antenna is not rejecting VHF as it should.

Because your Noise Margin on the Sacramento stations is so high, you can still receive them even with an antenna that has loss instead of gain. If you fix this problem you'll probably recover all the lost SF stations. It may very well kill VHF reception since the antenna will be working as designed and you'll have to add a VHF antenna.

I'd come up with something other than adding ropes and plastic to the 91XG to keep the TV's off of it. Maybe you could extend the mast just above the 91XG with PVC pipe and use a Tee junction with more PVC to be the same length as the 91XG boom and prevent the TV's from landing on it. You could use the end of the boom as a support for the long PVC. They could sit on the upper PVC.

Chuck
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post #10387 of 10402 Old 02-06-2015, 11:18 AM
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I performed a simple test inside the house to check my theory that the antenna pattern would be messed up if only one side of the coax was connected.

I set up a signal generator on UHF with a dipole as the transmitting antenna in a bedroom at the end of a hall that I could see in the kitchen 30' away. This reduced the reflections that could reach the receiver since the signal had to pass through a doorway. I used my little 8 element UHF LPDA as the receive antenna connected to my spectrum analyzer so I could measure the signal strength. I verified a normal antenna pattern with coax connected to the antenna. IOW the strongest signal occurred with the antenna pointing at the transmitter.

Then I connected a piece of coax that only had the center conductor making contact. The shield was open. The antenna pattern was completely changed and the signal was about 20 dB weaker. The weakest signal was when I was almost pointed at the transmitter. The strongest signal was when the antenna was off-pointed about 45°.

Since the 91XG is a different design than my LPDA, it would not be unexpected that the pattern with only half the coax connected would be much different.

My best educated guess is that you have an open connection somewhere in your system. It could be the cable. It could be the antenna balun.

Your symptoms fit the test results; best signals with the antenna off-pointed from the transmitters and weaker stations are not receivable. Also this would explain VHF reception. The antenna is not rejecting VHF as it should.

Because your Noise Margin on the Sacramento stations is so high, you can still receive them even with an antenna that has loss instead of gain. If you fix this problem you'll probably recover all the lost SF stations. It may very well kill VHF reception since the antenna will be working as designed and you'll have to add a VHF antenna.

I'd come up with something other than adding ropes and plastic to the 91XG to keep the TV's off of it. Maybe you could extend the mast just above the 91XG with PVC pipe and use a Tee junction with more PVC to be the same length as the 91XG boom and prevent the TV's from landing on it. You could use the end of the boom as a support for the long PVC. They could sit on the upper PVC.

Chuck
Wow, experimenting on my problem! Other than a VOM, are there any relatively inexpensive testing instruments you'd recommend? Like less than $50?

Once the roof dries off, I'll get up there and jumper the center and shield and see if it's open. Take a look at the balun, seems to me it was the typical one, not an enclosed circuit board.

After you mentioned the VHF stations, I'm confused about that. I thought the analog to digital was a move to UHF to free those VHF freq to be sold to cell phone companies. So how could KGO stay on the VHF? And the rest of the one's you mentioned? All of them are digital signals, but they're still on a VHF freq? Is that what is happening?

I have a small VHF antenna I bought 25 years ago and is in the attic, I'll grab that and install it and see what happens.

Again, mucho thanks.
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post #10388 of 10402 Old 02-06-2015, 12:02 PM
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Wow, experimenting on my problem! Other than a VOM, are there any relatively inexpensive testing instruments you'd recommend? Like less than $50?

No. Any equipment to run any serious tests is at least hundreds of dollars.

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After you mentioned the VHF stations, I'm confused about that. I thought the analog to digital was a move to UHF to free those VHF freq to be sold to cell phone companies. So how could KGO stay on the VHF? And the rest of the one's you mentioned? All of them are digital signals, but they're still on a VHF freq? Is that what is happening?

No, it's the opposite. The transition gave up UHF channels 52-69 for cell phone usage. There were no changes to either low or high VHF because antennas on those frequencies are too big for cell phones. Stations didn't want to be on low VHF (CHs 2-6) because DTV doesn't tolerate the high noise often found on those frequencies and the longer wavelengths are very poor at penetrating buildings making an outdoor antenna a requirement. Some stations reluctantly accepted high VHF channels (7-13) if no UHF channels were available. High VHF has much less problem with manmade noise but the longer wavelengths don't penetrate buildings as well as UHF so an outdoor antenna is still often required.


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I have a small VHF antenna I bought 25 years ago and is in the attic, I'll grab that and install it and see what happens.
That would be interesting to try.

Chuck
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post #10389 of 10402 Old 02-06-2015, 01:09 PM
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Just wanted to brag about my moms install real quick. TV fool makes it look pretty bleak, but she gets all the walnut grove stations.
http://www.tvfool.com/?option=com_wr...2c15795bc6528d
It's a rohn 25g 60' tower with a rotor at top and a 91xg UHF antenna and a hi-vhf winegard ya-1713 (discontinued).
It had actually been up for a year or so, but she was having trouble with ion. The pre-amp was a channel master CM-7777 (the older model with seperate uhf and vhf inputs).
I ended up using my kitztech kt-200 in a outdoor enclosure. It was the standard version with the DC plug on it, so I powered it with some spare copper from the cat5e I had running up to power/control the rotor. I also put a fm trap between the winegard vhf antenna and the uvsj.
It has been working perfect for over a month now. The only thing that messes with her signals is the inversions in the valley. I have sac, bay area, and Salinas programmed into her rotor. Salinas always comes in (8.1 and 8.2) in any type of weather.
Here's some pics. Next time I climb it I will take a panorama. The vhf antenna needs some repairs; a heavy bird bent the element and i tried to make a temporary fix with electrical tape.
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post #10390 of 10402 Old 02-06-2015, 02:48 PM
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Here's some pics. Next time I climb it I will take a panorama. The vhf antenna needs some repairs; a heavy bird bent the element and i tried to make a temporary fix with electrical tape.
Looks great! Any trouble with the rotor so far? How old is it?

Chuck
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post #10391 of 10402 Old 02-06-2015, 10:06 PM
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It is interesting how sensitive tuners are; the best was the CM digital analog conversion box. Sony 32" CRT from 2005 wasn't as good, about 75% of the CM box. Pany Plasma must have been built with a sat or cable input in mind, because the OTA tuner is pathetic compared to the first two. And the CM DVR is the worse of all....
If you have a couple of PCIe slots open in your PC, the Hauppauge WinTV-HVR-1265 PC tuner card is pretty much the most sensitive tuner you can get today (NOT the Hauppauge 2255 Dual tuner card which stinks.) A couple of 1265 cards should easily outperform your CM DVR+.
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post #10392 of 10402 Old 02-07-2015, 01:51 PM
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If you have a couple of PCIe slots open in your PC, the Hauppauge WinTV-HVR-1265 PC tuner card is pretty much the most sensitive tuner you can get today (NOT the Hauppauge 2255 Dual tuner card which stinks.) A couple of 1265 cards should easily outperform your CM DVR+.

I cringe when I hear everything attributed to sensitivity because without carefully measured tests we don't know if the issue is actually sensitivity or multipath handling. Sensitivity of a tuner can be measured with a step attenuator, a spectrum analyzer and a flat OTA signal. This is how I found out that my Sony TV minimum signal is -84 dBm which infers a noise figure of 6 dB. The only way to get better sensitivity is lower the noise figure. The minimum required 15.2 dB SNR cannot be lowered. It's certainly possible that the noise figure of a tuner could be lower but I'd be real surprised to find one more than 1 or 2 dB lower. Few people would be able to see such a difference in their everyday viewing.

I think multipath is a bigger problem with reception of local stations than is sensitivity but is very hard to measure differences between tuners in multipath performance without sophisticated test equipment.

Chuck
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post #10393 of 10402 Old 02-07-2015, 02:38 PM
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Originally Posted by Dee Barvo View Post
Antennas Direct 91xg, Eagle Aspen Rotr 100. I had to hose clamp some plastic pipe to the antenna and strung some rope over them to make it harder for the turkey vultures to land on it. They broke off all the elements on a big CM I had up there.

With the DVR, most of the SF stations disappeared, but currently watching KTVU, 2 out of Oakland, and I have a perfect picture and no dropouts. This with the antenna aimed due north.

Cranked it around to 206 and did a re-scan; still can't get 4,5,7,9,11 which are all the SF stations. Still getting the Sac Valley stations about as well as aimed north. This don't make sense, does it?
If the conditions are right, the reflected signals may be better. You need to establish whether or not you have LOS (line of sight) to the towers. TVFool says no, but it looks at an area around the size of a football field. This could be done with Google Earth. If there is a taller hill between you and the towers, the signals become 1-edge. In addition, you need to be pointing at hills that are at a greater elevation than your antenna. The hills would need to be LOS. These hills would also need to be nearby. I can't say how close they need to be exactly. Thus, a reflected LOS signal outperforms a direct 1-edge signal. This would have invited a double image with analog, but double images are no longer a concern with digital. A readable signal is all that's required.
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post #10394 of 10402 Old 02-07-2015, 05:30 PM
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Originally Posted by Dee Barvo View Post
Wow, experimenting on my problem! Other than a VOM, are there any relatively inexpensive testing instruments you'd recommend? Like less than $50?

Once the roof dries off, I'll get up there and jumper the center and shield and see if it's open. Take a look at the balun, seems to me it was the typical one, not an enclosed circuit board.

After you mentioned the VHF stations, I'm confused about that. I thought the analog to digital was a move to UHF to free those VHF freq to be sold to cell phone companies. So how could KGO stay on the VHF? And the rest of the one's you mentioned? All of them are digital signals, but they're still on a VHF freq? Is that what is happening?

I have a small VHF antenna I bought 25 years ago and is in the attic, I'll grab that and install it and see what happens.

Again, mucho thanks.
Calaveras is, as always, correct. KXTV is using their original analog antenna and it is a channel 10 transmitter sitting in the building. KVIE is also VHF.

Bob
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post #10395 of 10402 Old 02-08-2015, 12:22 AM
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I cringe when I hear everything attributed to sensitivity because without carefully measured tests we don't know if the issue is actually sensitivity or multipath handling.
Once again, everyone else out there accepts that if one tuner receives more stations than another tuner under the same conditions with the same antenna, it is considered to be more sensitive than the other tuner. That's what is accepted, multipath or no multipath. So just accept it.

The real problem is that DTV tuner and HDTV manufacturers fail to provide the consumer with ANY tuner performance specifications, (sensitivity, multipath rejection, selectivity, etc.) forcing the consumer to make uninformed buying choices resulting in many disappointing experiences and the proliferation of poor quality DTV products sold to American consumers who don't know any better. Back in the old Stereo Hi-Fi receiver days, those receiver/tuner specifications were routinely included in all user manuals, on the box, in sales brochures and most advertisements. Why does the FCC not require these specifications be made available with every DTV tuner/receiver? Why are we forced to rely on suspect online reviews and randomly buy and return junk instead of being able to compare specs and make informed purchase decisions?

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post #10396 of 10402 Old 02-10-2015, 08:01 AM
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Once again, everyone else out there accepts that if one tuner receives more stations than another tuner under the same conditions with the same antenna, it is considered to be more sensitive than the other tuner. That's what is accepted, multipath or no multipath. So just accept it.

The problem with letting this ride is that people think if they have trouble receiving a station it is because the signal is too weak and therefore they need a more sensitive tuner or a preamp or even worse a higher gain preamp. More often than not this is not the case.

Words have meanings and I'm not giving in to ignorant marketing. This is a technical forum. There's no reason why we can't use the correct terminology here.

Chuck
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post #10397 of 10402 Old 02-11-2015, 03:30 AM
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The problem with letting this ride is that people think if they have trouble receiving a station it is because the signal is too weak and therefore they need a more sensitive tuner or a preamp or even worse a higher gain preamp. More often than not this is not the case.

Words have meanings and I'm not giving in to ignorant marketing. This is a technical forum. There's no reason why we can't use the correct terminology here.
For the best DTV reception, you need a good antenna AND a good tuner. BOTH are important. But after you've futzed around for years with antenna systems to no avail, it's time to look at tuners. There are some really poor quality DTV tuners/receivers out there which fail to receive some of the strongest area station signals. I know. I've returned a few including Hauppauge's poorly performing new HVR-2255 dual tuner card with the same tuner/demodulator chips as the exceptionally well-performing Hauppauge HVR-1265 single tuner card (an under $70 investment if you have the PCIe slot.) If you start adding antenna towers, extra low-noise preamps, heavy duty rotors, heavy gauge cables, you are getting into a well over $1000 of investment. Add a professional signal analyzer to the mix to make sure everything is positioned right and to separate multipath issues from SNR issues, and we are talking airfare to the moon. So I think a serious DTV viewer should spend some time and a few dollars into getting the best available DTV tuner first before emptying his bank account on the antenna system. This REQUIRES manufacturers to post tuner performance specs so that consumers can make that choice without relying on untrustworthy reviews.

If you go online to Google for the best DTV tuner, you get nothing but antenna articles using the search string "HDTV tuner best reception". But if you Google "HDTV tuner best sensitivity", you get the exact website references to HDTV tuners you are looking for. The REAL WORLD uses the term "sensitivity" when they want DTV tuners with the best DTV reception. People use "Kleenix" when they mean "facial tissue." People use "most sensitive tuner" in place of "the tuner with the best reception." People know what is meant by DTV tuner sensitivity. You can live in your small world expecting everyone to adapt to your view of the meaning of "sensitivity", or you can speak the same language everyone else is speaking. I am going to continue to use "DTV tuner sensitivity" when referring to DTV tuner quality, so get used to it and leave it alone.
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post #10398 of 10402 Old 02-11-2015, 08:15 AM
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If you go online to Google for the best DTV tuner, you get nothing but antenna articles using the search string "HDTV tuner best reception". But if you Google "HDTV tuner best sensitivity", you get the exact website references to HDTV tuners you are looking for. The REAL WORLD uses the term "sensitivity" when they want DTV tuners with the best DTV reception. People use "Kleenix" when they mean "facial tissue." People use "most sensitive tuner" in place of "the tuner with the best reception." People know what is meant by DTV tuner sensitivity. You can live in your small world expecting everyone to adapt to your view of the meaning of "sensitivity", or you can speak the same language everyone else is speaking. I am going to continue to use "DTV tuner sensitivity" when referring to DTV tuner quality, so get used to it and leave it alone.

I know your comments about spending big money on antenna systems is aimed at my antennas. My towers, antennas, rotors, etc. are primarily for ham radio, not TV. The TV antennas just happen to fit the available mast space and are fun to play with. I'd have the same towers and other equipment TV or not. I had two towers up before I ever considered playing with TV antennas. If you'd like to see the complete setup go here:

http://www.qrz.com

type in "AA6G" and click on the thumbnail picture. The pictures are a little behind but you can see that the TV antennas are a small part of the setup.

I don't expect you to follow my lead and I'm not following your lead. I'm not a crowd follower. I'm not following the crowd when I know they're wrong. The greatest successes I've had is by not following the crowd.

Chuck
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post #10399 of 10402 Old 02-11-2015, 05:59 PM
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The problem with letting this ride is that people think if they have trouble receiving a station it is because the signal is too weak and therefore they need a more sensitive tuner or a preamp or even worse a higher gain preamp. More often than not this is not the case.

Words have meanings and I'm not giving in to ignorant marketing. This is a technical forum. There's no reason why we can't use the correct terminology here.

Chuck
Very good point and I completely agree. I talk with multiple viewers every day about reception problems. I will often find, after a viewer accuses us of reducing power or whatever, that the viewer is basing this on a low signal level. Sometimes that is the case. One of the most common signal level problems is defective splitters and connectors. Sometimes, it's someone who thinks he needs a preamp and that preamp is being overloaded, making things non-linear in his antenna system because he lives in Elk Grove. More often than not, however, the viewer's problem is multipath.....antenna pointed in the wrong direction, hill or building in the way, etc.

With that said, some tuners do handle multipath better than others.

Bob
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post #10400 of 10402 Old 02-21-2015, 08:04 AM
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KMMW is still off the air. Over a month now and no STA for silent operation.

In other news, K03HY on Mt. Tamalpias which is causing a lot of interference to KCSO on RF 3 is moving to a building in downtown San Francisco. The interference should disappear. It will be replaced by KTVJ on Mt. Tam on RF 4 perhaps in a few weeks. It's proposed to use virtual channel 39 which will create a virtual channel mess for me as I already have KMMD using VC 39.

Chuck
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post #10401 of 10402 Old Today, 03:22 PM
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Here's an interesting article that mentions the KXTV/KOVR and KCRA/KQCA towers at Walnut Grove:

https://medium.com/re-form/where-the...a-76b33694c99e

This link was provided by Lawrence Rhodes on the San Francisco OTA Yahoo Group: HDTV-in-SFbay@yahoogroups.com

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My complete SF Bay Area DTV Station Lists: http://www.choisser.com/sfonair.html
Lots of Broadcasting links and information: http://www.choisser.com/broadcast.html

Check out photos and info on my antennas: http://www. larrykenney.com/tvantennas.html

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post #10402 of 10402 Old Today, 03:53 PM
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Very informative article. Thanks for the link.
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