Fox 11 symbol quality dipping every 15-20 sec - MBrown2020

Reception, channel detection, network issues, CableCARD setup, etc.
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MBrown2020
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Joined: Sat Mar 07, 2020 11:33 am

Fox 11 symbol quality dipping every 15-20 sec - MBrown2020

Post by MBrown2020 »

Hello,
I have a HDHR Scribe Quatro tuner. I am interested in just 4 channels- ABC, CBS, NBC (all UHF), & Fox 11 (VHF-HI). I have perfect reception for the 3 UHF channels, but am having issues with the VHF-Hi Fox 11 channel.

I have good signal strength(~70%), signal quality(~65%). Every 15-20 seconds the symbol quality dips to around ~5% for a second then jumps back to 100%. I have tried different antenna placements, and 3 different antennas, but problem remains. I am currently using the stellar labs 30-2475 VHF-Hi antenna. Even when installing antenna outside as a test the problem remains. My TV tuners and my Hauppage WinTV HVR2250 in a different computer also don't exhibit this issue. It is strictly the HDHR Scribe Quatro.

Model: HDVR-4US-1TB
Device ID: 152019C7
Firmware: 20200225

I have checked the "send Diagnostic" box and ran a channel scan. I then tuned to Fox 11 for 10 minutes. Date Ran: March 7th, ~ 12:45pm CST

Any help would be appreciated, thank you.
Matthew

jasonl
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Re: Fox 11 symbol quality dipping every 15-20 sec

Post by jasonl »

What zip code are you in?

What is the signal path from the antenna to the HDHomeRun? Are you combining it with a separate antenna for UHF or anything like that?

MBrown2020
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Joined: Sat Mar 07, 2020 11:33 am

Re: Fox 11 symbol quality dipping every 15-20 sec

Post by MBrown2020 »

Zipcode = 54904

Signal path is from antenna through 20 ft coaxial to basement, then connected to HDHR. No splitters/amp currently connected.

MBrown2020
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Joined: Sat Mar 07, 2020 11:33 am

Re: Fox 11 symbol quality dipping every 15-20 sec

Post by MBrown2020 »

Seems like the quality of UHF channels is fine with that antenna, so no plans for one yet.

MBrown2020
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Joined: Sat Mar 07, 2020 11:33 am

Re: Fox 11 symbol quality dipping every 15-20 sec

Post by MBrown2020 »


jasonl
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Re: Fox 11 symbol quality dipping every 15-20 sec

Post by jasonl »

This is likely the typical "didn't RTFM when installing a Harris transmitter" issue that has affected a number of stations over the years. Basically, the transmitter has a feedback connector that it uses to monitor its own output and adjust power levels as needed to account for possible issues. If they don't hook it up, when it does the sampling and sees no signal, it cranks up the output level, then slowly backs it down, and the process repeats. Every time that spike happens, the signal gets distorted as the gain control tries to track it. The good news is that the repack is forcing them to move to a new channel, which means junking the old transmitter because it's obsolete and can't be retuned to operate on the new channel. So, everything should just magically work once they change channels, because the new transmitters don't have this kind of issue. WLUK is scheduled to move on 5/1.

MBrown2020
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Joined: Sat Mar 07, 2020 11:33 am

Re: Fox 11 symbol quality dipping every 15-20 sec

Post by MBrown2020 »

Thanks, i'll keep an eye on it until May.

Why do none of my other tuners exhibit this behavior, is this something just in the HDHRs.

MBrown2020
Posts: 7
Joined: Sat Mar 07, 2020 11:33 am

Re: Fox 11 symbol quality dipping every 15-20 sec

Post by MBrown2020 »

I found this PDF from rabbit73 over on AVS Forums titled:
-----------------------------------------------
HDHomeRun HDHR3 ATSC 30-Second Reception Issue
(20150121)

Silicondust has identified a problem receiving ATSC broadcasts from a small number of
broadcasters.

Affected models:
HDHR3-US, TECH3-US, TECH3-8US-2X4.

Affected broadcasters:
KABC (Los Angeles CA), KCNC (Denver CO), WHTM (Harrisburg PA), WLUK (Green Bay
WI), WNYT (Albany NY).
-------------------------------------------------

Would this still be relevant on the newer HDHR Scribe models to possibly fix this until May 1st channel change?

NedS
Silicondust
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Re: Fox 11 symbol quality dipping every 15-20 sec

Post by NedS »

Very unlikely to be related. The SCRIBE is basically a 5th generation tuner, while HDHR3/TECH3 devices are 3rd generation tuners. That specific issue, and the fix for that issue, won't apply to newer units.

jasonl
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Re: Fox 11 symbol quality dipping every 15-20 sec

Post by jasonl »

Thinking it's the same or a similar root cause, but the fix wouldn't apply since the fix described in that was loading a different microcode version into the demodulators in that device, and we haven't used that demodulator since gen 3. There really isn't going to be anything that can be done in the timeframe available. Even if we were to work with the vendor of the current chip to get an update to work around whatever is going wrong with WLUK, from past experience, it's about a 2-3 month process. By the time we had an update, WLUK would have switched to their new equipment and it would be irrelevant anyway.

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