Need more coax runs

[barnabas1969]

I thought I'd post to let the OP know that I ordered a couple of those balanced 3-way splitters to test the difference between feeding through the Cisco TA vs. connecting the TA & Tuner directly to the splitter. When I receive them, I'll hook them up and post my results. I'm curious to see if there will be a significant difference.

[barnabas1969]

Being the analytical type that I am (some might say anal, but I prefer analytical ), I just couldn't resist doing an experiment. When I got home, nobody was here... and the next scheduled recording wasn't until 8:30pm (and it will use one of my ATSC tuners anyway). So, I disconnected my cable modem, one of my TA's, and one of my HDHR Prime tuners. I connected the remaining HDHR Prime and TA directly to the cables in my wiring closet that come directly from the amplifier outside (no splitters in the path). My cable amplifier is a model EVO1-9-U/U.

Immediately before the experiment, I tested the same frequencies as I listed in a previous post again... because they can vary over time due to outside temperature, humidity, etc.

Before the test (using my usual configuration that feeds the TA's from a 2-way splitter, and the HDHRP's fed from the output of the TA's), I measured the following:

Freq:189MHz, Power:+7.6dB, SNR:36.8dB
Freq:548MHz, Power:-0.3dB, SNR:34.8dB
Freq:777MHz, Power:-2.0dB, SNR:34.7dB

During the test, with one TA connected directly to one of the amplifier's outputs, and one HDHRP fed from another output of the amplifier), I measured the following:

Freq:189MHz, Power:+8.1dB, SNR:37.1dB
Freq:548MHz, Power:+0.6dB, SNR:35.2dB
Freq:777MHz, Power: 0.0dB, SNR:35.5dB

First, I want to point out that my weakest (and lowest quality) channel is my highest-frequency channel. This is to be expected, because the overall circuit (including the amplifier, cables, splitters, etc. and the frequency range of the channels) is affected both by inductive reactivity and capacitive reactivity. So, the higher frequencies will be lower-powered, and therefore have a lower signal to noise ratio. To put it simply, you will usually see a slope like mine... the low frequency channels will be stronger than the high frequency channels.

As you can see, eliminating the 2-way splitter and the feed-thru of the Cisco TA affected both power and quality (The power can be attributed to both the TA and the splitter, and the SNR is mostly attributed to the Cisco TA's internal amplifier, because amplifiers always inject some noise which decreases SNR).

The power increased 0.5-2.0dB (avg 1.33dB), and the SNR increased 0.3-0.8dB (avg 0.5dB).

So, the worst case scenario, using a Cisco/SA tuning adapter in my original configuration, indicates that as long as the signal for my weakest channel (as delivered from my cable provider at the point-of-entry) is at least -5.0dB @ 32.8dB, I'll be just fine.

My cable company actually has much looser tolerances... they say that if the signal level at the input of your device is at least -15dB, and the SNR is at least 28dB, it should work. Ceton says that their tuners will work with a +/- 10dB input (and I don't think they specify the SNR). Many people recommend staying in the +/- 7dB range. From my experience (and I think the OP will agree), the Silicondust HD HomeRun Prime tuner is much more sensitive/selective than the InfiniTV, and therefore can operate reliably at lower signal strength/quality than the InfiniTV tuners.

In conclusion, the difference between connecting your Tuner/TA directly to the output of the amplifier, vs. connecting them to a 2-way splitter and feeding the Tuner from the TA's output, is negligible... at least for the Cisco/SA Tuning Adapters. This may not be the case for the Motorola TA's.

[barnabas1969]

Oh, also... in case it isn't immediately apparent, the Cisco TA seems to amplify the input signal 1.5-3dB, depending on frequency, based on my test.

[hmmurdock]

Thanks for reaffirming pretty much everything I've said since the beginning. I'm glad we could finally find some common ground.

[barnabas1969]

Thanks for reaffirming pretty much everything I've said since the beginning. I'm glad we could finally find some common ground.

Oh, you make it too easy. I'm not sure how I "reaffirmed" what you said. What I showed was that the differences are so negligible as to make your argument irrelevant. Now, let's review what you recommended...

In post #9, you recommended this:

And, that means that the OP will need to spend at least $70.00 on another amplifier, and he'll be daisy-chaining amplifiers... which degrades SNR (more than a splitter).

Then, later, you said that the OP could move his 8300 amp to the basement/closet and then put a splitter in the original location where the 8300 amp used to be located. Well, the OP said that all 8 outputs were in use, so that means that he would need either a 6-way splitter (not easy to find) or a 2-way splitter feeding two 3-way splitters (remember, daisy-chaining splitters is a bad idea... and, per you... all those extra "junctions" are evil. So, that means you are recommending one of the two configurations below:

Both of those options involve 9-11dB of attenuation (not to mention all those evil "junctions")! So, if the signal he is receiving from the cableco is not really, really strong... guess what??? He's going to have signal strength that is so low that many tuners won't work reliably!

Yep, that's right... your advice sucks... no matter how you want to justify it.

You're just too easy.

[hmmurdock]

So much for not responding to me anymore. I had a feeling that wouldn't last.

You reaffirmed exactly what I've been saying all along... that all things being equal you'll get a worse signal when you split it (and/or amplify it) than if you don't. Your little experiment confirmed just that.

And brilliant job of overlooking the obvious. I guess it would be just way to difficult to pick up an 8 way splitter to drive the old legacy equipment. A quality splitter and a pair of 75ohm terminators can be had for a under $10. Neither are rare. Neither are expensive.

Would that result in a lower signal to his legacy equipment? Yes. Is that equipment usually as sensitive as newer equipment? No. Again, I'll ask, which equipment needs a better signal, then new tuners and modems, or old TVs? Which does it appear the OP is more concerned with?

I'm suggesting 1 Amp and 1 splitter (that doesn't even effect the devices in the wiring closet)

You're suggesting multiple splitters, and depending on which TA's multiple amps as well. All things being equal, that's going to result in a worse signal. There is simply no way around that. Might it work? Of course. No one has ever said otherwise. But there is also a possibility that it won't.

We're talking about spending basically the same amount of money, and we're talking about spending basically the same amount of time. The difference is, (per your own testing) with your suggestion the devices in the wiring closet will get a measurably worse signal. going with my suggestion the wiring closet devices will get a measurably better signal, and the legacy devices will get a lower signal. Which is more important?

(oh and prior to upgrading my equipment, my TWC signal was strong enough to run all of my analog tuners and Motorola DVR boxes just fine, through an 8 way splitter but as always, ymmv)

But by all means, keep ranting that I'm trying to get the OP to do a bunch of extra work, or spend a bunch of extra money. You either still don't understand what I've suggested, or you're intentionally misrepresenting what I've said. Whatever the reason, you look more foolish every time you do it, which is just fine by me.

[barnabas1969]

So much for not responding to me anymore. I had a feeling that wouldn't last.

Yeah, sorry... I just couldn't resist responding to your ignorant post. My bad.

You reaffirmed exactly what I've been saying all along... that all things being equal you'll get a worse signal when you split it (and/or amplify it) than if you don't. Your little experiment confirmed just that.

Yep, and as I've been saying... the degradation isn't worth mentioning, let alone your lengthy posts attacking my position.

And brilliant job of overlooking the obvious. I guess it would be just way to difficult to pick up an 8 way splitter to drive the old legacy equipment. A quality splitter and a pair of 75ohm terminators can be had for a under $10. Neither are rare. Neither are expensive.

An 8-way splitter will have an 11.5dB insertion loss. That's much, much worse than what I've suggested. You keep saying stuff about the OP's "most sensitive" vs. his "legacy" equipment, as if to say that the other tuners in his house will be immune to an 11.5dB insertion loss. That's just wrong.

Would that result in a lower signal to his legacy equipment? Yes. Is that equipment usually as sensitive as newer equipment? No. Again, I'll ask, which equipment needs a better signal, then new tuners and modems, or old TVs? Which does it appear the OP is more concerned with?

Well, I'll admit that the InfiniTV4 PCIe tuner was very finicky. My experience with the HDHR Prime is much different. Either way, his "legacy equipment" may be more or less sensitive than the HDHR Prime. Certainly, an 11.5dB insertion loss could be a problem, even for "old TV's".

I'm suggesting 1 Amp and 1 splitter (that doesn't even effect the devices in the wiring closet)

True, your suggested configuration will give the TA's and HDHRP's the best signal. But you seem to ignore the fact that an 11.5dB insertion loss for the rest of the devices in the OP's house will probably be enough to cause them to malfunction.

You're suggesting multiple splitters, and depending on which TA's multiple amps as well.

No, I gave two options. The first is for situations where the tuner can work reliably when fed by the TA's output. The second is for situations when it won't. Neither results in an insertion loss greater than 5.5dB. Don't forget that the OP's existing amplifier boosts the signal by 3dB... so the net is only -2.5dB in the worst case of my two recommendations. That's nothing! If the signal at the utility drop is anywhere near normal, a 2.5dB drop won't affect anything. Your suggestions all result in either SNR that is degraded by daisy-chaining amplifiers, or signal strength that is attenuated up to 11.5dB, resulting in a net loss of 8.5dB. A drop of 8.5dB will most likely result in problems! Duh!

We're talking about spending basically the same amount of money

No, we're not! You're talking about spending a minimum of $10 on a 8-way splitter (which will attenuate the signal too much) or a maximum of (at least) $70.00 for an amplifier that will be daisy-chained to another amplifier!

and we're talking about spending basically the same amount of time.

True.

The difference is, (per your own testing) with your suggestion the devices in the wiring closet will get a measurably worse signal.

Yep, measurably insignificant

going with my suggestion the wiring closet devices will get a measurably better signal, and the legacy devices will get a lower signal. Which is more important?

Going with your suggestion will get a signal to the "legacy devices" that probably won't work at all. How do you know the sensitivity/selectivity of the devices in the OP's house? For all you know, he has some devices in his house that are much less sensitive/selective than the HDHRP! You're basing your opinion on your experience with the InfiniTV4-PCIe that you own. I hate to break this to you, but the HDHRP has much better sensitivity/selectivity than the InfiniTV4-PCIe. It's entirely possible that the OP has other devices in his house that are less sensitive/selective than the HDHRP. How can you assume that it's OK to attenuate the signal to the rest of his house by 11.5dB?

(oh and prior to upgrading my equipment, my TWC signal was strong enough to run all of my analog tuners and Motorola DVR boxes just fine, through an 8 way splitter but as always, ymmv)

Analog tuners are much more forgiving than QAM tuners. If the signal sucks, an analog tuner will display a (degraded) picture. If the signal is below the ability of a QAM tuner to reliably tune that channel, you'll get nothing... or at best, the picture/audio will drop occasionally. The OP didn't happen to mention what type of devices are connected to the other 6 outputs of his amp. It's irresponsible to suggest an 11.5dB drop to those devices without knowing more about his situation.

[STC]

Due to posts that have had to be deleted, this thread is now closed.