Bolt's crappy OTA tuners

Discussion in 'TiVo Bolt DVR/Streamer' started by Saturn, Dec 7, 2020.

  1. Dec 7, 2020 #1 of 29
    Saturn

    Saturn Lord of the Rings

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    I have been dealing with my Bolt's apparently crappy OTA tuners for a couple years. I'm really close to the antennas for our area (I can see both from my backyard) and I put an overkill UHF antenna outside because it was easy to do and I split the signal 8 ways once it gets into the house, then most of those get split again (e.g. direct to TV, and to a TiVo).

    Anyway, after much futzing I got a digiair pro atsc signal meter and it revealed something interesting - if a signal is greater than 0 dBmV, the TiVo will pixelate. Apparently its built-in attenuator can't handle really strong signals. Anyway, I've played with attenuators and selective attenuators and finally ended up just turning the antenna slightly to keep the top two channels at less than 0 dBmV at the TiVo. Great. Except now a 3rd channel (physical channel 11, at -3dBmV) is screwing up, and adding attenuation isn't working.

    So maybe this is multi-path, maybe interference, but every other tuner in the house (multiple TVs, and an HDHomeRun) don't have any issues on ANY stations, no matter what direction the antenna is pointed.

    I feel like I'm babying this one crappy TiVo tuner and I'm kinda done with it. My family doesn't really use the TiVo anymore and I only use it once a week during football season. I have Plex DVR setup, but it has its own issues, like 30-second skip on a Fire Stick has jittery playback for 0-2 seconds afterward. I don't really want a monthly subscription so Channels DVR is out.

    I'm loathe to spend more money on this setup, but are there any TiVos with known-better tuners? I have the TCD849000, are any of the OTA-only TiVos any better?

    And yes, I've pulled my TiVo apart to check the ground on the coax is still in place.
     
  2. Dec 7, 2020 #2 of 29
    A J Ricaud

    A J Ricaud Active Member

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    Maybe try an LTE filter?
     
  3. Dec 7, 2020 #3 of 29
    Saturn

    Saturn Lord of the Rings

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    I looked at that, but the station having issues is low frequency (VHF 11 - 201Mhz), and LTE is channels 38-50 (700mhz+).
     
  4. Dec 7, 2020 #4 of 29
    Saturn

    Saturn Lord of the Rings

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    I ordered a (Philips) LTE filter. I don't have high hopes, but it can't hurt for $10.
     
  5. Dec 7, 2020 #5 of 29
    ClearToLand

    ClearToLand Old !*#$% Tinkerer!

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    How does the DigiAir Pro ATSC Signal Meter compare to the HDHomeRun Diagnostics: (Understanding the signal, strength, and quality readings reported by the HDHomeRun )?

    I currently have a VHF PBS station located ~5 miles away, on a hill, that, using rabbit ears, I can only receive in the winter time (leaves off trees) using a rabbit ear / UHF loop antenna. During the summer it pixelates like mad. Growing up in a borough of NYC (long, long, ago...), neither my immediate family nor any relatives living nearby had need for anything but rabbit ears (most portable b/w tvs of the era had built-in rabbit ears) for NTSC VHF.

    Regardless of the signal strength reading on my Roamio OTA (~50-55 IIRC), I couldn't get a stable picture. Once I connected the HDHR3-US I found that only one position of the ~12 position rotary switch on the base of the antenna resulted in 100% Symbol Quality. I found that interesting.

    From this experience, rather than spend ~$350 for a professional ATSC Signal Meter, I suggest that most folks start with a ~$50 HDHomeRun tuner. As with many other technical 'things', if you can't measure it (i.e. oscilloscope, X-10 Signal Meter, Multimeter, etc...), you can't fix it.
     
  6. Dec 7, 2020 #6 of 29
    Saturn

    Saturn Lord of the Rings

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    The station having issues on the TiVo shows 94% signal strength, 100% signal quality and 100% symbol quality on my HDHomeRun. But a different station that is reporting slightly stronger in the Digiair pro is showing 90/100/100. A definite lower signal channel is showing 68/100/100, so it seems to be a decent proxy for the signal strength as reported by the Digiair. Which one is more accurate? Hard to tell.
     
  7. Dec 7, 2020 #7 of 29
    ClearToLand

    ClearToLand Old !*#$% Tinkerer!

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    IMO, most 'techies' / 'semi-techies' from the NTSC VHF era are accustomed to dealing with just signal strength on some type of meter and actual signal quality by viewing the picture on a tv. Thus, a high signal strength reading for today's ATSC signals is misleading them (temporarily discarding the fact that over 100% usually isn't reported) - per the HDHomeRun LINK I provided above, Signal Quality and Symbol Quality are now part of the equation.

    Is it safe to assume that the unlabeled three number groups in your post are values for the HDHomeRun in the order listed in my LINK?
     
  8. Dec 7, 2020 #8 of 29
    Saturn

    Saturn Lord of the Rings

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    Yes, strength/signal quality/symbol quality, the order in the app and documentation.
     
  9. Saturn

    Saturn Lord of the Rings

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    Unfortunately, the LTE filter made no difference. I left it on the line (and removed my MoCA filter, as it is redundant) anyway.
     
  10. shwru980r

    shwru980r Well-Known Member

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    I have my antenna mounted to a rotator that is controlled by a control box at my TV. I can move the antenna one degree at a time and check the signal of each channel until I find the perfect antenna position. I think you should try an antenna rotator.
     
  11. Saturn

    Saturn Lord of the Rings

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    I'm going to try moving the antenna, and maybe building my own. The one I have is very directional which isn't great because the three antennas in the area are all in significantly different directions. The main two are 90 degrees apart from each other and the 3rd is 180 in the other direction entirely. They're all close enough that I can pick them all up no matter what direction the antenna is pointing, but signal strength varies quite a bit when turning it. Also, the antenna is mounted on an old satellite TV mast stuck in the ground on the side of the house. One of the big antennas is straight through my neighbor's house, and our house is aluminum siding. I suspect some of this is messing things up. I'm thinking a DIY bowtie, fractal or omnidirectional loop antenna with no reflector stuck in the middle of the back yard may be better.
     
  12. A J Ricaud

    A J Ricaud Active Member

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    Hacienda...
  13. aspexil

    aspexil Active Member

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    The thing about any antenna is if you want to improve reception you need to get it as high above ground level as possible. If the neighbors house of aluminum siding is in your line of sight then that will definitely degrade your signal quality.

    If there are any trees in your area you could try tossing a rope over a branch and pull the antenna up that way. I hang many of my amateur radio shortwave dipoles that way. You'll obviously need more coax.

    As mentioned you can join multiple antennas. Most any spiltter will work in reverse as a joiner. You might have to be careful of feedline/coax length on either side so you don't introduce other issues. That is how I have our antennas currently configured in our attic which is 50' above ground level and pretty much pull in 60 stations here in Indy.
     
  14. Saturn

    Saturn Lord of the Rings

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    I don't have a weak signal though. I have to have a 10dB attenuator an 8-way and a 2-way splitter on the signal just to get the signal below 0dBmV. I may be confusing signal strength with quality, but they are certainly related, no?
     
  15. barnabas1969

    barnabas1969 Active Member

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    If the transmitters are so close, why did you install an outdoor antenna? You are severely over-driving the tuners in all of your devices. If your TV's can handle such a strong signal, kudos to the manufacturers of your TV's!

    ATSC signals are amplitude modulated. When the signal is too strong, the demodulator in your tuner cannot detect the differences in amplitude.

    When you are that close to the transmitters, A simple, non-amplified, pair of rabbit ears should do.

    If you can actually SEE the transmitters from your back yard, you could probably just take a piece of 75 ohm coax and strip off the insulation and the shield, exposing about 13 inches of the center conductor... and THAT will function as an "antenna". Just make sure that the center conductor does not touch any metal objects. Also, make sure that the shield (usually braided wire or metal foil) does not touch the center conductor.

    If you make such an "antenna" from a piece of 75 ohm coax (with a male F connector on one end), try to orient the bare copper center conductor perpendicular to the floor (ie. either point it up or down).

    You could do this for very little cost. Heck, if you PM your shipping address to me, I'll make it for you. I have plenty of spare 75 ohm coax, and plenty of male F connectors laying around.

    Here's a tutorial for creating your own dipole antenna. It's a little more sophisticated than what I proposed above, but it will work well also...

    Blue View - Make Your Own TV Antenna — Just a Little Further
     
    Last edited: Dec 15, 2020
  16. Saturn

    Saturn Lord of the Rings

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    So maybe a little background would help. When cutting the cord, I wanted an outdoor antenna for reliability, away from interference of devices in the house, etc. At the time I had 3 TiVos (series 3s) and was using my coax for MoCA too. Between the MoCA, TVs and TiVos, I had 7 or 8 points in the house that needed connections, and some of those points was again split three ways - a TV for direct tuning, a TiVo, and a MoCA adapter. The line comes from outside and goes into an 8-way splitter in the basement (-11dB), and each splitter at the branch locations subtracted 3.5dB, so another 3.5 to 7dB loss. Without taking into account the coax itself, that's 18dB loss. I knew this was non-trivial loss, I really didn't want to get onto the roof, and the two major transmitters in the area were 90 degrees apart, so I got a completely overkill antenna and put it on the previous owner's DirectTV pole in the backyard, put new ends on the existing coax, pointed each half roughly at the antennas, and hooked it into the house's coax, and I was able to draw in every station on every TV and TiVo perfectly. This worked for years, until TiVo basically forced me to replace the Series 3 TiVos with a single Bolt and a few TiVo minis. That's when I started having problems with one particular station. After much futzing I eliminated half of that DB8e essentially turning it into this antenna, and still needed attenuators and noticed the Bolt had issues with any station above 0dBmV (I also noted that it cuts out entirely around -24dBmV). Some more futzing and repointing along with an additional 10dB attenuator on the line and all stations are right below 0dBmV at the same splitter the TiVo is connected to. The previous stations that were having issues for being too strong are no longer having issues, but a different station (measured at -3dBmv) is still having issues.

    Yes, it is still an overkill directional antenna, mounted 4' off the ground on a pole rather than the roof or attic, and probably too close to the aluminum siding of our house and maybe blocked by the neighbors for one antenna.

    I do have plans to make my own much smaller antenna, something like the OA-432, experiment with mounting options (middle of the yard away from the house, up a tree, on the roof, etc) and see if I can pull in a signal strong enough to still feed the whole house without an amplifier. I'm just waiting for a balun to arrive. I may end up with the thing mounted inside, barely above grade in my basement between the rafters, particularly since we just got snow and then a cold snap..

    To complicate things, there is a 3rd antenna with a much weaker signal in a completely different direction from the other two I would also like to pull in, but it isn't one of the major networks so I could do without.
     
  17. barnabas1969

    barnabas1969 Active Member

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    You have created your own problem. Have you tried a simple antenna as I suggested in my earlier post?

    If you can actually SEE the transmitter towers... you should NOT have an outdoor antenna. Hell, a simple piece of wire stuffed into the F connector on your Bolt should provide more than enough signal for the tuner.

    Sometimes, "overkill" creates problems. Use the K.I.S.S. principle whenever possible.


    KISS = Keep It Simple, Stupid.

    You have created a Rube Goldberg version of your antennae.
     
    Last edited: Dec 15, 2020
  18. Saturn

    Saturn Lord of the Rings

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    Yes, I could probably stick a piece of wire into my Bolt and get decent reception on the strongest stations but then the Bolt couldn't connect to MoCA and the TiVo minis couldn't connect to it, Yes, I hook up an external MoCA/Ethernet adapter to the Bolt and solve that problem too. I'm guessing the weaker stations in the area wouldn't work or at least wouldn't work reliably. Then I have two antennas, one directly into the Bolt and another (still outside) for everything else in the house, and the one inside would be subject to people walking around, phones, Wifi, the microwave and whatever else leaks RF.

    Tuners have built-in attenuators to handle strong signals just fine, it just seems that the Bolt's is particularly crappy and sensitive to other issues (multipath?) that none of the other tuners I have (Panasonic TVs, a Samsung TV, HD HomeRun, even a crappy Homeworx thing) seem to have trouble with.
     
  19. Saturn

    Saturn Lord of the Rings

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    And yes, I realize I've overengineered it and caused my own problems here.
     
  20. barnabas1969

    barnabas1969 Active Member

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    Your WiFi does not transmit on the same frequencies as OTA (Over The Air) TV stations. The frequencies are not even close.

    In your situation... because you are close to the transmitters... here is what I recommend:

    First, connect a VERY SMALL antenna, such as I described earlier.

    Since you want to use MoCA, the output of that antenna should be connected to a POE Filter such as this:
    https://www.amazon.com/TiVo-Authorized-Point-Entry-Filter/dp/B01EKCL1U6/

    The output of the POE filter should be connected to a SINGLE SPLITTER. It is NOT acceptable for one splitter to feed into another splitter, and so-on. You should NEVER daisy-chain splitters.

    If you require more outputs, you should purchase a unity-gain amplifier, like this: https://www.amazon.com/gp/product/B003UH9R2C
     

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