One Big Variable

There are always reports of LPWs to one degree or another (and always will be). People consider such variables as network, device, cabling, etc. But one big variable that will always stay VARIABLE is antenna performance.

As summer rolls around, heat, air pressure and humidity will take their toll on OTA reception. Channels that came in clearly over winter will degrade. They will be better in cool mornings and evenings but worse during much of the day. Leaves which were absent the season before will disperse signals so that antennas previously aligned will be out of alignment. The antenna stays in a fixed position but the signal does not.

I have found especially with one channel that LPWs predictably increase as that channel’s SNR decreases. The Tablo buffers after a signal break to try and recapture the stream.

Signal reception is one big variable that is true to its category - variable. That is one major factor users have to consider when evaluating a Tablo’s performance when LPWs occur.

That is one major reason why cable became popular in the 60’s after the 50’s were antenna based: eliminating the variableness of reception. ATSC 1.0 did not address that problem very well; ATSC 3.0 is meant to reconsider that problem.

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Which is why I thought that repeats (shows) were just fine for summer as this was my worst season for reception. I was satisfied with having good reception from September to May and spent more time outdoors from June to August rather than in front of the TV…

This is one reason for the success of a multi-bay antenna such as the Channel Master 4228. It has a large capture area and therefore works better than the Yagi in wooded areas where a signal is dispersed and fragmented. The multiple whiskers distributed vertically and horizontally try to account for the fact that a signal may be several inches above at one moment and several hours later may be inches (or feet) lower. AntennasDirect markets their DB8e and Clearstream4 antennas for tree “disadvantaged” areas. A Yagi prefers clear and open spaces with LOS.

People stack multiple antennas horizontally and vertically because signals may shift left or right, up and down. One moment an antenna whisker or director may be getting the signal and then hours later be in a null signal position. A distribution of antenna elements statistically, from a probability standpoint, has a better chance of intercepting a signal or signals.

I have observed and measured daily where my FOX signal is strongest at a certain height in the morning and as the day progresses the signal comes in at lower angles. A vertical stack accounts for this signal movement in which the signal horizon shifts.

The unenviable situation for an OTA DVR to be in…when its source is variable…:fearful:

PS will be interesting to see what Nuvyyo can accomplish with their Metro Tablo (embedded antenna) especially inside city canyons.

As mentioned in a previous ATSC 3.0 thread, ATSC 3.0 is looking at fixing the ATSC 1.0 drawback - OTA reception. Here from a recent ATSC 3.0 presentation about new transmission equipment:

“Earnshaw also explained that ATSC 3.0 has a wider operating capacity than ATSC 1.0, the current standard, and is flexible in that a lower capacity is more robust, and vice versa. He also noted how the standard’s use of OFDM accommodates single frequency networks, which in turn can increase a signal coverage area throughout problematic terrain using a multiple-input, single-output, or MISO, transmission scheme.”

Looking forward to the time when OTA transmission & reception is LESS variable…

It’s good that ATSC 3.0 has the ability to support MISO. Customers are going to need it once channels get repacked and move from UHF to VHF.

And I don’t mind a repack in which the majority of the channels are Hi VHF and low UHF. My GH antennas operate best with channels 8 to 11 and 19 to 27. Upper UHF is a PITA. The industry can take them and repurpose them for mobile.

Channels are auctioned off in 6 MHz chucks. Broadcasters can’t infringe on adjacent frequencies. Thus ATSC 1.0/2.0 has a maximum capacity. While there are improved efficiencies with ATSC 3.0 there is still a limit on bandwidth. So only so many sub-channels can broadcast on the same frequency with a major network.

Repacking will reduce the number of sub-channels. And with ATSC 3.0 and 4K support and repacking the sub-channel losses could increase. There is limited bandwidth within a frequency.

The majority of channels broadcast on UHF. If VHF was so efficient why wouldn’t the government auction off VHF channels and repack the smaller number of VHF channels into UHF.