EXTEND scan only finds one channel but I can watch two

[johnwmaustin]

I live in St. John's Newfoundland. There are two OTA TV channels here: CBC TV 8.1 which is detected by every scan.
The second channel NTV 21.1 is never detected by scans but I can use HDHomeRun_Config_GUI to select either channel. Several years ago I had a setup with a Raspberry PI, MythTV (as I recall) and a PC running NextPVR.

Data from HDHomeRun_Config_GUI (results are similar for both tuners).

Channel 8 - CBC TV - detected and usable on all apps
Signal Strength % 100%
Signal Quality % 77%
Symbol Quality % 100%
Channel 21.1 - NTV TV - not detected and usable in some apps
Signal Strength % 100%
Signal Quality % 98%
Symbol Quality % 100%

I'd like to use Plex running on a Beelink mini S where I see two channels in the EPG but can't seem to add the 21,1

Both stations are located about 4 miles away. My choice of antenna doesn't seem to matter.

Could LTE interference be my problem ?
I have been assuming that missing EPG data in the 21.1 signal but Plex appears to have a second source. I may have fallen into the confirmation bias trap.

[signcarver]

With plex you should be able to manually add channel without scan. I never like seeing 100% strength as you don't know how much above 100% it is and such is often quite suseptible to lte interference across everything as it may overload the internal amplifier but the shots you showed don't seem to indicate such is a problem and I suspect the noise (lower quality) you see on the one you get is just the nature of that frequency.

I am a bit surprised at those levels the scan isn't finding it but keep in mind to add to scan it needs data of virtual channel number and name to properly add. I would also test with each tuner and while using both tuners as sometimes an early indication of power supply failure is a particular tuner having issues or having issues when both tuners are in use (such as during a scan).

[johnwmaustin]

I noted this morning that the NTV Channel 21.1 is centred at 515MHz and 4G LTE in Canada makes some use of frequencies around 600 MHz. I don't have a functioning SDR right now to use as a spectrum analyser but I have ordered an LTE bandpass filter from SiliconDust to see if it helps.

I had a similar experience with a Table Oh two-channel device several years ago. The support tech from Table Oh reported that the missing channel was reported as a 'protocol error' when he connected to mine and did a scan. It never helped and I recently bricked my Table Oh so there is nothing I can do about that now.

If I say the competing brand name ***** it is censored but Table Oh is not.

[jasonl]

We would like to get some diagnostic data to see what is happening:

1. In a web browser go to http://hdhomerun.local
   NOTE: That address will go do the first HDHomeRun device found on your network. If you have more than one HDHomeRun device, use the "device ID" printed on the bottom of the unit instead of "hdhomerun" in the address. For example, if your device ID was 104FFFFF then you would go to http://104fffff.local
2. Click "System Menu"
3. Check the "Send diagnostic information" box (if this box is already checked, please un-check then re-check it)
4. Go back one page
5. Click "Channel Lineup"
6. Click on "Detect Channels"

Reply back and provide us the device ID of your HDHomeRun and we will check the logs. You can find the device ID on a label on the bottom of the HDHomeRun itself.

[johnwmaustin]

Thank you. I followed your directions and the Device ID is 10513C8B.

[johnwmaustin]

The data from today was run in a slightly higher ambient temperature. The device will eventually live inside the house but is next to the antenna for testing.

I connected a SiliconDust LTE filter yesterday in the hope that it might work through some fluke. It didn't.

[NedS]

Can you run another channel scan with the LTE filter connected and reply back?

[jasonl]

It looks like CJON/NTV's PSIP generator isn't working. This is the device that inserts the channel names and numbers, among other things, into the broadcast. You may want to contact the engineering group at the station and ask them to check on it. At most stations, it's the single most unreliable piece of equipment in the entire place, and some of them need to get rebooted every few weeks to keep things operational.