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I find it interesting that the only channels you are receiving are actual VHF channels. Do you have the power supply installed and plugged in?
San Francisco, CA - OTA
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Yes the power supply is plugged in.
I do get a number of UHF channels like 14.x, 26.x, 36.x .... , but I am not picking up UHF from Sutro Tower.
We need to see your Rabbitears report to give you antenna advice. Sounds like you may be in a poor location for Sutro.
RabbitEars.Info
RabbitEars, where you can learn all about local, over-the-air TV channels.
www.rabbitears.info
The antenna you have is probably inadequate for your location.
Chuck
Here is the RabbitEars report : RabbitEars.InfoWe need to see your Rabbitears report to give you antenna advice. Sounds like you may be in a poor location for Sutro.
RabbitEars.Info
RabbitEars, where you can learn all about local, over-the-air TV channels.
The antenna you have is probably inadequate for your location.
Chuck
Path Profile from Sutro Tower.
Is it a fools errand trying to get reception in this location? Or will a better antenna installed higher help?
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By looking at your RabbitEars report, you're in a very difficult reception area. I re-ran the report with the antenna up to as high as 100 feet and it didn't significantly change the results. I used to live in Pleasanton near Valley and Santa Rita and that was a difficult reception area for Sutro even with a good UHF antenna. I am familiar with your neighborhood and feel your pain. When I lived there, I used to call the entire Tri-Valley Area "RF Hell".
My report is worse than yours and I receive my stations fine BUT you're surrounded by hills and I'm in an open plain with low multipath. It's likely you have terrible multipath that no antenna may be able to overcome. If I was going to try it, I'd put up an XG91 for UHF. It has the best rejection of any antenna I've seen but it can't work miracles.
Chuck
Hello, B0ka245, welcome to the Tri-Valley RF drain. This is a very difficult area because the high hills create a shadow that causes multipath (variable interference when the same signal comes from different directions at different times). I could write pages about this, as I've lived with it for 20 years, but I'm going to be brief, for now.
The result is very location specific - your neighbor may get better or worse results than you.
A really good antenna (high gain and high interference rejection) with a really good preamp (low noise, overload immunity) up around 30 ft or more is the minimum required. The biggest baddest antenna is needed. XG91 is one choice as noted, another is the Televes Dat Bos Mix LR. You will also need a rotor because the exact azimuth positioning of the antenna is critical, and may vary during the day as the multipath varies.
What also helps is a TV tuner that is good at handling multipath. The best I've found is the internal tuner in the LG OLED TV's. There are many times that the LG can pick up a near perfect signal when no other tuner can get anything stable.
You may also have to experiment with different antennas, different heights, and different locations.
As you've already found, VHF is easier to get than UHF - because the lower frequencies can "bend" more and get around the hill obstructions.
You may have better luck tuning in the Sacramento stations from Walnut Grove than the Sutro stations. Of course, then you'd get Sacramento local programming, not SF. Also, the stations transmitting from Fremont may be much easier to get than the Sutro stations.
Bottom line is that you'll have to be experimental and patient to find something that works - even then, it may not work 100% of the time.
With all that bad news, here's some possible good news coming around the bend: when ATSC 3.0 starts transmitting, it may solve all our problems, because it's designed to deal with difficult multipath situations like ours. But here in the Bay Area it looks like it's a couple of years away.
Hope that helps - it's reality at least.
The result is very location specific - your neighbor may get better or worse results than you.
A really good antenna (high gain and high interference rejection) with a really good preamp (low noise, overload immunity) up around 30 ft or more is the minimum required. The biggest baddest antenna is needed. XG91 is one choice as noted, another is the Televes Dat Bos Mix LR. You will also need a rotor because the exact azimuth positioning of the antenna is critical, and may vary during the day as the multipath varies.
What also helps is a TV tuner that is good at handling multipath. The best I've found is the internal tuner in the LG OLED TV's. There are many times that the LG can pick up a near perfect signal when no other tuner can get anything stable.
You may also have to experiment with different antennas, different heights, and different locations.
As you've already found, VHF is easier to get than UHF - because the lower frequencies can "bend" more and get around the hill obstructions.
You may have better luck tuning in the Sacramento stations from Walnut Grove than the Sutro stations. Of course, then you'd get Sacramento local programming, not SF. Also, the stations transmitting from Fremont may be much easier to get than the Sutro stations.
Bottom line is that you'll have to be experimental and patient to find something that works - even then, it may not work 100% of the time.
With all that bad news, here's some possible good news coming around the bend: when ATSC 3.0 starts transmitting, it may solve all our problems, because it's designed to deal with difficult multipath situations like ours. But here in the Bay Area it looks like it's a couple of years away.
Hope that helps - it's reality at least.
Appreciate the excellent info @wb6lzv @Calaveras and @Les H.
The Televes Dat Boss Mix LR may be a good option for me, has UHF and VHF elements with decent gain. As for the TV's I have Samsung (they have decent tuners) and a brand new Sony X900h with ATSC 3.0 tuner. Both TVs pickup the same exact channels. Waiting for Bay Area to start ATSC 3.0 transmissions.
Can someone please recommend a competent installer in this area. I am forbidden to climb on our two-storey roof.
The Televes Dat Boss Mix LR may be a good option for me, has UHF and VHF elements with decent gain. As for the TV's I have Samsung (they have decent tuners) and a brand new Sony X900h with ATSC 3.0 tuner. Both TVs pickup the same exact channels. Waiting for Bay Area to start ATSC 3.0 transmissions.
Can someone please recommend a competent installer in this area. I am forbidden to climb on our two-storey roof.
Just note that the Televes Dat Boss Mix LR is really good at UHF but not nearly as good at VHF - it probably is not enough antenna at VHF, so you may need a better, separate VHF antenna.
As a reference point, I know of one capable Bay Area antenna installer who refuses to work in the Tri-Valley area, because it's so difficult to achieve good results, and people blame him instead of the geography. I don't know of anyone specialized and capable who works in this area. Some installers who aren't familiar with this area incorrectly think they can use the same kind of antenna installation that works in other areas, but that will not function here.
What I've done is hire handymen or roofers or gutter cleaners who are comfortable working on roofs, and then have directed them what to do in setting up the antenna. So you'd need to become knowledgeable enough to do that.
Can't wait for ATSC 3.0, which should make life simpler for us.
As a reference point, I know of one capable Bay Area antenna installer who refuses to work in the Tri-Valley area, because it's so difficult to achieve good results, and people blame him instead of the geography. I don't know of anyone specialized and capable who works in this area. Some installers who aren't familiar with this area incorrectly think they can use the same kind of antenna installation that works in other areas, but that will not function here.
What I've done is hire handymen or roofers or gutter cleaners who are comfortable working on roofs, and then have directed them what to do in setting up the antenna. So you'd need to become knowledgeable enough to do that.
Can't wait for ATSC 3.0, which should make life simpler for us.
My measurements below. The 14 element high VHF yagi should be close to the Stellar Labs 30-2476.
Chuck
Dimmed signals are stations in directions other than Mt. Bigelow and cannot be compared here.
I hope that's the case. Expectations are high but I'm unaware of any head to head tests. And even if the high expectations are met, a complete switchover to ATSC 3.0 is probably many years off.
Chuck
You need to use "Curved Earth" to see how bad the path really is. Rabbitears uses curved Earth in its terrain plots. Click on "Transmitter Distance" to see the plot.
Chuck
Some 3.0 stations should be on the air in the next year so we'll be able to find out how well ATSC 3.0 works under multipath conditions. It has been tested in and worked from moving vehicles, which are worse conditions than my fixed position multipath.
During your spectrum analyzer scan comparing various antennas were all of them in passive, non-amplified mode, including the Televes? That would disadvantage the Televes by several db because its always-in-line preamp has some losses in passive mode.
The antenna tests were run using a KT-200 preamp so that means the Televes preamp was not powered. I did not see much difference in SNR between using the integrated Televes preamp and the external KT-200. Others have measured significant loss with the Televes preamp in passive mode. The problem is that it doesn't go away when powered up.
Insertion Loss in Passive mode (unpowered)
UHF Noise Figure - Preamp powered (Traces are Noise On/ Noise Off)
Chuck
Televes active antennas do not have any insertion loss when used in active mode with the amplifier receiving power and working (which is how they are designed to be used) other than an around 0.5dB loss due to the input saw LTE filter. The passive pass-through does incur significant insertion loss and it is intended as an "auxiliary mode" of sorts only, when the available signals are so strong that said insertion loss is irrelevant, or more importantly in the event power fails to reach the preamp for any reason so that the antenna continues to work, albeit at a lowered performance level. Other active antennas do not do this and just fail to work when power fails, this behavior is also better than the alternative of a mast mounted amplifier failing to receive power and interrupting signal flow altogether.
Therefore any spectrum analyzer screenshots, parameter values, and/or conclusions drawn with a DAT LR or any other Televes amplified antenna used in passive mode with the addition of an external third party preamp will show a very significantly diminished performance due to the C/N degradation incurred in that set up. Conclusions, measurements and graph representations derived from such an exercise are apples-to-oranges, uninformed, inaccurate, and in summary, just plain wrong.
The NF values posted by this individual are also way off, probably because the error is being carried over and the methodology is flawed. It is also unknown how those supposed insertion losses are being measured, since the dipole input where the preamp resides is adapted to the antenna impedance of around 300 ohm balanced (depending on the particular antenna) and not at 50 or 75 ohms, so measuring at the input of the amplifier with a 50 ohm unbalanced meter will not provide any real valuable information.
I would encourage any interested readers to disregard this misinformation and reach out to Televes directly with any doubts, concerns or for accurate feedback. The RED (radio equipment directive) specifies the FoM (figure of merit) for the characterization of active antennas. The exercise of comparing noise floors to measure NF is incorrect and leads to wrong conclusions. The FoM is related to the antenna gain, the noise power and the NF of the amplifier. Televes active antennas are RED compliant and have been characterized and tested by the most prestigious laboratory in the industry, PKM in Germany.
To reiterate, the posted values and graphs by this poster in this and several other threads in this forum are wrong. They do not represent the real performance of a DAT LR antenna when used as intended and, although the time and dedication are very much appreciated, they portrait a very misleading picture of the product -probably unintended- and are to be deemed completely irrelevant.
I tried a 300 ohm balun and the noise figure was still poor. How about you provide some of your own measurements? Maybe you have a problem in production models and don't know it. I'm not the only one who's measuring these sorts of numbers. I've measured a lot of preamps and have obtained reasonable numbers. There have been a few poor performers over the years. I'm using the same measurement technique that was approved by our engineers at work to measure NF on equipment that went into US submarine microwave systems. I kind of doubt I'm doing it wrong.
I trust the measurements I make because I've been doing them for so long. I don't believe what someone just tells me because too often it turns out to be wrong. They have to provide actual test data and a test setup. Quoting specs provided by the factory is not good enough.
I can tell from what you've written that you don't understand what I'm doing. I am not comparing noise floors to measure noise figure. I'm using noise source noise on/off to find the difference and then plugging that number into the formula to calculate noise figure. This is one of several accepted methods to measure noise figure.
Setting the noise floor the same to calibrate out different line loss and preamp gains and then swapping antennas is a perfectly valid way to see differences in antenna gain.
BTW, the Televes stand alone preamp I measured had the noise figures printed on the case but were sort of lined out, still readable. My measurements were very similar.
If required, I can provide more details about the test setups.
I trust the measurements I make because I've been doing them for so long. I don't believe what someone just tells me because too often it turns out to be wrong. They have to provide actual test data and a test setup. Quoting specs provided by the factory is not good enough.
I can tell from what you've written that you don't understand what I'm doing. I am not comparing noise floors to measure noise figure. I'm using noise source noise on/off to find the difference and then plugging that number into the formula to calculate noise figure. This is one of several accepted methods to measure noise figure.
Setting the noise floor the same to calibrate out different line loss and preamp gains and then swapping antennas is a perfectly valid way to see differences in antenna gain.
BTW, the Televes stand alone preamp I measured had the noise figures printed on the case but were sort of lined out, still readable. My measurements were very similar.
If required, I can provide more details about the test setups.
The specifications of Televes products are public, and as it has been mentioned they comply with strict international regulations which are independently verified by world class recognized laboratories in the industry.
Every single unit is individually verified during the manufacturing process to ensure it meets specs and goes through the most stringent quality assurance protocols in the digital terrestrial television industry. Every single individual PCB is fully electrically and optically verified at several stages along the automatic manufacturing line, all active parts and functional blocks extensively double checked and measured, and every single product component is fully traceable down to the manufacturing run, raw materials origin, and particular batch of parts employed. Insight into some of these processes for a particular model of antenna can be seen here:
It is no coincidence that the MTBF of these products is the lowest in the industry. As an example, the failure rate of DAT BOSS antennas sits at a 0.06% after millions of units have been installed in countries around the world.
Again I’d recommend discerning consumers and professionals alike to not allow themselves to be mislead by flawed measurement exercises, misinformation and uninformed conclusions posted in internet forums, particularly when a product is purposely not used as intended. Anybody is welcome to reach out to our US office directly to clarify questions and concerns: [email protected] / (720) 379-3748
Every single unit is individually verified during the manufacturing process to ensure it meets specs and goes through the most stringent quality assurance protocols in the digital terrestrial television industry. Every single individual PCB is fully electrically and optically verified at several stages along the automatic manufacturing line, all active parts and functional blocks extensively double checked and measured, and every single product component is fully traceable down to the manufacturing run, raw materials origin, and particular batch of parts employed. Insight into some of these processes for a particular model of antenna can be seen here:
It is no coincidence that the MTBF of these products is the lowest in the industry. As an example, the failure rate of DAT BOSS antennas sits at a 0.06% after millions of units have been installed in countries around the world.
Again I’d recommend discerning consumers and professionals alike to not allow themselves to be mislead by flawed measurement exercises, misinformation and uninformed conclusions posted in internet forums, particularly when a product is purposely not used as intended. Anybody is welcome to reach out to our US office directly to clarify questions and concerns: [email protected] / (720) 379-3748
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