Optimizing OTA HDHR Signal Strength/Quality

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KeithAbbott
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Optimizing OTA HDHR Signal Strength/Quality

Post by KeithAbbott »

Apologize if this has been covered elsewhere, if so feel free to point me to the answer. I have three different OTA HDHR devices, all fed by a Televes antenna & amplifier. Each HDHR has it's own in-line coaxial attenuator, to tamp down the signal for the channels that HDHR is set up to receive. Overall, the setup seems to be working pretty well.

So my question is: what is the best procedure to use to determine the optimum attenuator value for a given HDHR? What I usually do is start with no attenuation, and then incrementally increase the attenuator (3db, 6db, 8db, etc.) until the signal strength dips just below 100. But I don't know if this approach results in the most optimized setup or not. For instance, once I find the attenuator value that causes the signal strength to dip just below 100, should I bump the attenuator value up by 2-3db so that the signal strength is slightly above 100?

I also just picked up a SignalScout, so if there is a better way to optimize SS or SNQ with that device that would work as well.

Thanks in advance for any assistance provided!

jasonl
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Re: Optimizing OTA HDHR Signal Strength/Quality

Post by jasonl »

The signal strength for any particular channel doesn't really matter that much when an amplifier is in use. Overload happens because of the total combined power going in, so assuming an LTE filter that blocks the 600MHz band is in there, I'd probably just try to get the strongest signal to around 110% and call it good enough.

KeithAbbott
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Re: Optimizing OTA HDHR Signal Strength/Quality

Post by KeithAbbott »

Thank you for the update. So I will be using the SiliconDust LTE filter.

Then for each HDHR, I will find the attenuator value that dips the signal strength just below 100 for the channel with the strongest signal strength that I am accessing on that device. Once I find that attenuator value, I'll bump it down one step, which should get me over 100 (and hopefully not over 110). Since the HDHRs do not display anything greater than 100, that's probably the best I can do.

I'll probably also try this with my SignalScout, since it can display signal level (is this the same as signal strength?) in dBm. Normally, I would connect it before the amplifier, but in this case I can connect it after the LTE filter, amplifier and attenuator, which should allow me to calculate the dBm level that 110% corresponds to.

Again, thanks for the information. Let me know if I am misunderstanding anything!

KeithAbbott
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Re: Optimizing OTA HDHR Signal Strength/Quality

Post by KeithAbbott »

One other question: am I correct in the assumption that for ATSC 1.0 channels, all sub-channels (x.2, x.3, etc.) are broadcast at the same power level as the main channel (x.1)? In other words, if I optimize the signal strength for the main channel, all of the subchannels would then be optimized as well?

Freekick123
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Re: Optimizing OTA HDHR Signal Strength/Quality

Post by Freekick123 »

KeithAbbott wrote: Wed May 29, 2024 6:30 am One other question: am I correct in the assumption that for ATSC 1.0 channels, all sub-channels (x.2, x.3, etc.) are broadcast at the same power level as the main channel (x.1)? In other words, if I optimize the signal strength for the main channel, all of the subchannels would then be optimized as well?
Yes, for ATSC 1.0 all the subs are equal.

signcarver
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Re: Optimizing OTA HDHR Signal Strength/Quality

Post by signcarver »

For the same frequency but it may not be as simple as x.1, x.2.... as some markets will have a variety of stations carrying the signals, particularly if there is an atsc3 lighthouse that gets its old channels scattered around on other stations.

KeithAbbott
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Re: Optimizing OTA HDHR Signal Strength/Quality

Post by KeithAbbott »

signcarver wrote: Wed May 29, 2024 7:07 am For the same frequency but it may not be as simple as x.1, x.2.... as some markets will have a variety of stations carrying the signals, particularly if there is an atsc3 lighthouse that gets its old channels scattered around on other stations.
In my area (southeast Michigan), WXYZ's signal is multiplexed with the following sub-channels: 7.1, 7.2, 7.3, 7.4, 7.5, 20.1, and 20.4.

20.1 and 20.4 are broadcast on behalf of another station. But my assumption is that 20.1 and 20.4 are broadcast at the same power level as 7.1 thru 7.5. Is that correct?

KeithAbbott
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Re: Optimizing OTA HDHR Signal Strength/Quality

Post by KeithAbbott »

jasonl wrote: Tue May 28, 2024 5:22 pm The signal strength for any particular channel doesn't really matter that much when an amplifier is in use. Overload happens because of the total combined power going in, so assuming an LTE filter that blocks the 600MHz band is in there, I'd probably just try to get the strongest signal to around 110% and call it good enough.
KeithAbbott wrote: Tue May 28, 2024 7:34 pmI'll probably also try this with my SignalScout, since it can display signal level (is this the same as signal strength?) in dBm. Normally, I would connect it before the amplifier, but in this case I can connect it after the LTE filter, amplifier and attenuator, which should allow me to calculate the dBm level that 110% corresponds to.
I found this post, which says that 100% signal strength for HDHR's equates to -48.75 dBm. So 110% would equate to around -42.75 dBm. Using my SignalScout, if I can adjust the attenuator value so that the signal level is between -48.75 dBm and -42.75 dBm, that should optimize things from a signal strength perspective.

I know this probably seems like overkill, but I am trying to prepare to drop cable TV in a few months, and I want my OTA to be as rock solid as possible.

nickk
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Re: Optimizing OTA HDHR Signal Strength/Quality

Post by nickk »

Suggest aiming for 90%. Nothing is gained (sorry) by hitting 100%.

KeithAbbott
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Re: Optimizing OTA HDHR Signal Strength/Quality

Post by KeithAbbott »

jasonl wrote: Tue May 28, 2024 5:22 pm The signal strength for any particular channel doesn't really matter that much when an amplifier is in use. Overload happens because of the total combined power going in, so assuming an LTE filter that blocks the 600MHz band is in there, I'd probably just try to get the strongest signal to around 110% and call it good enough.
nickk wrote: Wed May 29, 2024 9:57 pm Suggest aiming for 90%. Nothing is gained (sorry) by hitting 100%.
OK, thanks everyone for the information and guidance. I think I have my optimization strategy: since the signal strength fluctuates a fair amount, I will target to keep the SS primarily between 90% and 100%, but not less than 90%. If it exceeds 100% (which I'm certain it will on occasion), that's OK, so long as it stays under 110%.

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