Low OOB SNR: Comcast or Bad Ceton InfiniTV6?

[Erik]

I’ve been unable to pair my CableCARD with Comcast due to a low OOB SNR (8-17.5).

Comcast technician came out and tested my lines by doing a visual inspection of all the physical lines then tested my signal by connecting a standard Comcast HD receiver to the same line I would have been using for the Ceton InfiniTV6 card. The standard SNR reading from the Comcast box is showing an SNR of 37 (this is the same SNR I was seeing on my cable modem) and signal strength of +5, these are the numbers I would have expected and are pretty ideal from what I’ve been reading. However, when we looked at the OOB SNR on the Comcast HD receiver the signal is around a 20-21, this is not good, i.e. not allowing for the Ceton InfiniTV6 card to pair. Because the Comcast HD receiver was pre-paired it did not have any issue receiving the signal and we were able to navigate to multiple channels as expected. Comcast is telling me that this OOB SNR is within their range for their devices.

A few other trouble shooting points to note:

1. I have tried to pair three different CableCARDs, none of them were successful due to an OOB lock.
2. When I disconnect the coax cable from the Ceton InfiniTV6 the SNR does not change (I am monitoring the signal via WMC Diagonstics), the signal just keeps jumping around the same range: 8 to 17.5. This doesn’t seem correct to me, the signal strength drops to -50 when I disconnect but the SNR doesn’t change.
3. The OOB range via WMC jumps around from a low of 75.250 all the way up to 116.250 with many different MLZ in between.
4. I have opened a ticket with Ceton but the support so far has not been good, I can’t get a live person to talk to.
5. I’m half tempted to order another Ceton InfiniTV6 to see if it’s just my card and another one would work, the coax dongle on the back of the card doesn’t exactly give me confidence that it’s not the root cause.

As of now Comcast is telling me that there is nothing they can do to “fix” or “boost” the OOB SNR up to the range (37 ideal) that is required for the Ceton InfiniTV6 card. What suggestions do you have to get this resolved or am I out of luck with Comcast as my service provider and need to explore other live programming options?

I’m at a bit of a loss and hope someone could shed some light on my issue.

Thanks in advance for the help,
Erik

[JohnW248]

Did you always have tv service from Comcast or just internet service?

If you are a "new" tv service customer, there is a chance that Comcast has "left" a filter in your line that blocks the low end of the spectrum. If your Comcast buddy had used a full spectrum analyzer instead of a "tv set" he would have been able to determine if there was a notch out at the OOB frequency which is usually around 74-75 Mhz and not a difficult signal to get (unless it's been trapped out).

[Erik]

Here is the bad part, I have had Comcast TV service for years but I’ve never actually used it. It was included as part of a package when I hooked up my Internet service, I had DIRECTV service.

The technicians (plural) both did not use a full spectrum analyzer, they only used the standard hand held analyzer that did not read the OOB frequency, the only way they have analyzed the OOB frequency was to hookup another Cable box.

[JohnW248]

The fact your OOB is hunting is an indication that there is no signal there to lock on. You need to get them back and get it escalated to a lead for your area. They need to read the signal at the input to the Ceton device. Also make sure you have the "right" cableCARD. It has to be multistream and you need to know if you're on a Moto or a Cisco headend. Comcast has given out the wrong type of card on more than one occasion.

Have you sent a diagnostic scan along with your ticket to Ceton? And make sure they know the cable company and your area....they have people that can get in touch with cable systems where the user runs into difficulty.

Make sure that all the wiring is from Comcast and you don't have any splitters or cables you've bought.....let them wire it in and verify that you get a signal.

And make sure your card is registered as "inserted" in the WEB GUI (the default address is 192.168.200.1) under the cableCARD tab

[Erik]

Update: Ceton has taken over communications with Comcast to hopefully resolve my OOB Lock issue. I will update this thread as I get resolution.

[glugglug]

I had an issue for 5 days where channels below 200MHz were getting too low an SNR to tune. In fact, below the low threshold of SNR that the InfiniTV can measure. Most other channels were fine! Even stranger, the broken channels had appropriate signal levels, and a carrier lock but no digital lock. OOB lock was OK, but showed only 11dB/10 OOB MER (I now see 39dB/10 OOB MER).

Turned out to be a connector not completely tightened, which must have gotten loose during basement renovations. Before finding the loose connector I had thought I had broken the Ceton card because I stepped on the mini-coax to regular coax adapter when moving the PC (which yanked it off the card)! Check and make sure all splitters/cable extension adapters/etc. are tightened all the way, at least as far as you can hand tighten them.

It's like the partially loosened F connector acts as an FM antenna?

[barnabas1969]

When a connector is loose, the shield may not be properly grounded. This would definitely explain a low SNR. You should use a wrench or pliers to tighten all your connectors, not just your fingers.

[Erik]

After six visits from Comcast and me taking my machine to their office that has a direct fiber connection I was still unable to pair my CableCARD. I will give credit to Comcast, they went above and beyond to try to get my card working but after all is said and done the Ceton PCI card is defective. Now I need to jump through the return hoops process.