Missing channels...

Reception, channel detection, network issues, CableCARD setup, etc.
John-Galt
Posts: 39
Joined: Tue Aug 28, 2018 5:15 pm

Re: Missing channels...

Post by John-Galt » Sun Feb 17, 2019 2:56 pm

theboyk wrote:
Sun Feb 17, 2019 1:07 pm
Huh?

The splitters are the only thing making it work on the HDHR. If I remove the splitters, I only get 10 channels. When I add both splitters, I get 29 channels.

Doesn’t make any sense at all though.
SD tuners are very sensitive to what's called Tuner Overload. Without getting deep into the RF theory, let's just say that one or more strong TV channels can overwhelm the tuners ability to see the weaker channels. When you add attenuation, which is what adding one or more splitter does, the level of the strong channel is reduced to below the critical level which the tuner can handle.

See here for more info https://www.google.com/search?q=Tuner+Overload

This behavior in the SD tuners is a direct result of the design decisions SD made. Other tuners such as those in your Channel Master DVR and TV are simply better at resisting overload.

It could also be that a nearby LTE cell site is overloading your SD tuner. LTE filters are available from Channel Master and others. Antennas with built-in LTE filters are also available from several places.

Adding attenuation and/or an LTE filter takes care of the Tuner Overload on SD tuners for most people.

Your SD tuner is probably no worse than any other SD tuner since adding attenuation helps.

theboyk
Posts: 12
Joined: Mon Feb 11, 2019 8:43 am

Re: Missing channels...

Post by theboyk » Mon Feb 18, 2019 7:27 am

Just a quick follow up after some more tinkering last night. I reversed the splitters. I’d previously had the 2-way splitter first, then the 4-way...now it’s 4-way then 2-way. Getting 29 channels now.

ABC (7.1) and it’s 3 subs (as you said earlier) are still giving me trouble, but they were never all that stable with the CM DVR either.

Everything else is coming in great. Going to DL the older Mac app later today and have a look at the numbers. But things seem to have settled in nicely.

And everything is making sense now based on what everyone is saying. Definitely a LOT of new cell towers have gone up since I put the antenna up 10 years ago, so the overpower/interference/HDHR sensitivity combination seems to be the issue. So, ordering an attenuator and LTE filter and will report back once those are installed.

Once spring rolls around and I’m not buried under ice and snow, I’ll probably go up on the roof and re-aim the antenna a bit. But, for now, the HDHR is pulling in what I was expecting, so that’s great.

Thanks for all the help!

theboyk
Posts: 12
Joined: Mon Feb 11, 2019 8:43 am

Re: Missing channels - arid

Post by theboyk » Mon Feb 18, 2019 3:53 pm

Any suggestions on the type of attenuator to look for to help eliminate the issue? Going to order both that and the LTE filter, but not sure which attenuator I’d be looking for?

jasonl
Silicondust
Posts: 14249
Joined: Sun Oct 28, 2007 9:23 pm

Re: Missing channels...

Post by jasonl » Mon Feb 18, 2019 4:00 pm

I would either try to find a variable attenuator or just get a pack of five 3dB ones, so you can add and subtract as needed. Just make sure whatever you get has F connectors on it, not SMA or BNC, which are used for non-TV applications.

John-Galt
Posts: 39
Joined: Tue Aug 28, 2018 5:15 pm

Re: Missing channels - arid

Post by John-Galt » Tue Feb 19, 2019 9:50 pm

theboyk wrote:
Mon Feb 18, 2019 3:53 pm
Any suggestions on the type of attenuator to look for to help eliminate the issue? Going to order both that and the LTE filter, but not sure which attenuator I’d be looking for?
Just to give you an idea, a 4-way splitter has about 8 dB of loss; a 2-way is about 4 dB. So what you're using now equals 12 dB of loss, total.

I would install the LTE filter first, followed by only as much attenuation as is necessary. If you truly have LTE interference, you may find you don't need much attenuation at all.

Roginator
Posts: 12
Joined: Fri Jan 20, 2012 2:32 am

Re: Missing channels...

Post by Roginator » Tue Feb 19, 2019 11:51 pm

I'm no expert by any means, but shouldn't any unused splitter ports be capped?
https://www.amazon.com/d/Power-Cable-Te ... B000AAN76Y

John-Galt
Posts: 39
Joined: Tue Aug 28, 2018 5:15 pm

Re: Missing channels...

Post by John-Galt » Wed Feb 20, 2019 1:56 pm

Roginator wrote:
Tue Feb 19, 2019 11:51 pm
I'm no expert by any means, but shouldn't any unused splitter ports be capped?
https://www.amazon.com/d/Power-Cable-Te ... B000AAN76Y
Absolutely. Forgot to mention that. Thanks for the reminder...

theboyk
Posts: 12
Joined: Mon Feb 11, 2019 8:43 am

Re: Missing channels...

Post by theboyk » Mon Mar 11, 2019 12:04 pm

Just wanted to drop an update. Received the inline LTE filter on Friday and over the weekend I removed the splitters I had and replaced with the LTE filter. Ran a channel scan and back to only getting 10 channels. Plugged the splitters back in, and back to 23 channels (tried with an without the LTE filter; didn't make a difference that I could see, but I was only channel surfing, not looking at the numbers).

So, next up...replace the splitters with attenuators.

lukeau
Posts: 1
Joined: Sat Apr 13, 2019 8:49 am

Re: Missing channels...

Post by lukeau » Sat Apr 13, 2019 8:58 am

Hi,

I suspect I have signal issues also caused by too much signal (about 3km direct line of sight to the tower).
I will buy https://www.jaycar.com.au/4g-lte-filter ... n/p/LT3062 tomorrow and try it.

Regarding attenuation, one of the guys at work said instead of using attenuators he moved his aerial to point slightly from the tower until the signal level dropped. Does this sound plausible? I would rather not have to order attenuators and have to wait for them to arrive.

Thanks

NedS
Silicondust
Posts: 434
Joined: Mon Dec 10, 2018 12:38 pm

Re: Missing channels...

Post by NedS » Sat Apr 13, 2019 9:23 pm

lukeau wrote:
Sat Apr 13, 2019 8:58 am
Hi,

I suspect I have signal issues also caused by too much signal (about 3km direct line of sight to the tower).
I will buy https://www.jaycar.com.au/4g-lte-filter ... n/p/LT3062 tomorrow and try it.

Regarding attenuation, one of the guys at work said instead of using attenuators he moved his aerial to point slightly from the tower until the signal level dropped. Does this sound plausible? I would rather not have to order attenuators and have to wait for them to arrive.

Thanks
It would depend on how directional your antenna is, but it's entirely possible.

vmstek
Posts: 4
Joined: Tue Sep 25, 2018 9:33 am

Re: Missing channels...

Post by vmstek » Thu Jun 06, 2019 7:35 pm

Coincidentally, I am also in Toronto (central Etobicoke), and recently noticed I lost about half my channels also. Normally HDHomerun detected 35 channels, yesterday it was down to just 15. Today's scan restored most channels, but WUTV, normally one of the most reliable is still missing.
Fortunately I spent 30 years at Rogers as an RF engineer, and my home equipment is headend quality, so it won't be much trouble to troubleshoot the system once I make the time.

lancetruthhammer
Posts: 1
Joined: Tue Aug 27, 2019 5:35 am

Re: Missing channels...

Post by lancetruthhammer » Tue Aug 27, 2019 5:42 am

I found this to be a very useful discussion. I just recently purchased a new Quatro to replace my old (still working) Connect. Sadly, some of my channels were missing (37 went down to 27).

I figured, as I typically have figured, that the signal was too *weak*. So, I removed a splitter between the Quatro and the TV. No change, the channels that used to be showing up and were still showing up on the TV were not being detected by the Quatro.

I found an old 8-way splitter that I had not been using. The reduction of strength on this was about 10 vs the 3 (db?) of the two-way splitter. Employing this 8-way splitter led to all 37 channels being detected on the Quatro *and* the TV. All is well.

Important take-aways, at least for me here: (1) your signal can be too strong in some cases (which I hadn't realized), and (2) the Quatro is a bit more sensitive to the signal strength than the older Connect model.

Post Reply