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Originally posted by frankz1
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My splitters say right on them that they attenuate the signal by 3dB, so the fact that removing a splitter would amp your signal by 3dB is hardly an experimental breakthrough.
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Whoa, Uncle


If you have noise on the line it will also be increased 3dB when you remove the splitter. Hence, if the noise level on the line is significant with respect to the noise introduced by the box, you simply won't see the 3dB increase in SNR. If you do see the 3dB increase, it means almost all the noise is introduced by the box. Get it now ?

Quote:
What would be fairly scientific would be if - say - Comcast came out when you were having problems and hooked up a signal meter to measure your SNR at the line and then comparing that to what the box was reporting. Hmmm...let me see...oh, yes. That's exactly what happened here! And the fact, your unscientific and wholly pointless experiment "not withstanding," is that they both showed the same reading when connected to the same feeder line, nephew.

This is exactly the outcome you would expect if the noise on the line is greater than the noise introduced by the box. Then the line SNR will equal the box SNR ( the noise introduced in the box is negligible compared to line noise. No wonder you were having problems). But, if the noise on the line is the negligible noise, the SNR will increase when you remove the splitter, and you will discover (perhaps to your horror) that it is the box introducing all the noise.
 

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Quote:
Originally posted by MarcL
Why don't you get the 6412 and use it for recording HD, and get a second standard digital cable box that the Tivo can then control to supply the signal to the Tivo box. Should only be a couple bucks extra per month, and you can split the cable before the two boxes, and have the best of all worlds, and then there is no chance the Tivo ever screws up your recordings on the 6412.


Just an idea.

Thanks! Yes that crossed my mind too. It's $5/month for an extra STB. I'll use it as a last resort...


I PM'd the AVS member who did this exact 6412 setup with a ReplayTV and he indicated it works great.
 

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Quote:
Originally posted by frankz1
My splitters say right on them that they attenuate the signal by 3dB, so the fact that removing a splitter would amp your signal by 3dB is hardly an experimental breakthrough.

I noted my SNR, removed a splitter right before my TV, and the SNR went to zero, re-connected the line, with just a barrel connector, to the line going to the DVR, and then the SNR was exactly the same; so what does this mean? (Because I am getting lost with this discussion.)


BTW, what splitters only attenuate 3db?

I have only seen 3.5db and 4db splitters.
 

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Quote:
Originally posted by QZ1
Did you buy the amp from the Cable co. or did you buy your own?

What amp did you get?

Anybody else who bought an amp, please respond.

I bought this ONE. I needed more amplification for higher stations and less for lower channels. These are the same line that the cable co uses.


Best,

jeff
 

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Quote:
Originally posted by greeno
I bought this ONE. I needed more amplification for higher stations and less for lower channels. These are the same line that the cable co uses.


Best,

jeff

Sounds like a that amp is pretty nice, but pricey. I've had very good results with ratshack models (I currently use two) like this one: http://www.radioshack.com/product.as...t%5Fid=15-2505
 

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Quote:
Originally posted by QZ1
I noted my SNR, removed a splitter right before my TV, and the SNR went to zero, re-connected the line, with just a barrel connector, to the line going to the DVR, and then the SNR was exactly the same; so what does this mean? (Because I am getting lost with this discussion.)


BTW, what splitters only attenuate 3db?

I have only seen 3.5db and 4db splitters.

This would mean that you have noise on the line much greater than the noise introduced by the box. This would be unusual, as the "nominal" SNR of the incoming signal is 40dB. I suppose this is at the pole, and you certainly lose 3dB with each splitter (and perhaps introduce additional noise). In addition you lose signal in the cable runs and connectors in the house. Without knowing the actual SNR, it's hard to say if this would be a problem. If the SNR is well above 30dB, say 32+, I wouldn't worry about it.


I would tune both tuners to the same channel, and note the SNR and AGC numbers for each channel. Then I would remove the splitter and hook the splitter input line (not using the barrel connector) to the box if possible and note the readings again.


If you can post those readings, I'll be glad to give you my ideas on your situation, but I'll say right now that if you're not having any problems you are fine and will probably stay that way. After all, your tuners could be exceptionally quiet. in which case the line may very well be the noisy component.
 

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Quote:
Originally posted by dmlove51
For the second time, I set up Desperate Housewives as a series recording, channel 707 only. The first time, it recorded on Channel 7 (non-HD), as I noted last week (and others confirmed). It recorded last Sunday just fine, but when I checked for next Sunday, it wasn't scheduled, and it turned out the series recording had been lost. All my other schedules season passes were fine.


Also, for the second time, in the middle of "swapping" tuners, I lost everything - all guide data, etc. I really don't know whether this was something I did (I doubt it) or a local Comcast problem (Burlingame, CA). Did this happen to anyone else, maybe around 8:30 last night?

Hey, DM. I'm in Los Altos Hills and was programming my 6412 and similar to you, at 7:50pm last night, my box reset and lost all my guide data (it's pretty much all reloaded by now 2:30pm the next day). First time I've seen this.


In the process I learned some things. One is that it didn't lose any shows I had recorded. Secondly, it didn't lose any of the recordings I had scheduled, it just listed them as "Wed 8-9 channel 7" rather than "Lost", similar to what I see for manual recording, and sure enough 10 minutes later it started recording. That show then showed up in the listing as "Wed 8-9 channel 7". But over time as the guide filled back in, subsequent scheduled recordings filled back in with show names and if so got recorded and listed by name. This suggests it relies on the guide to find and schedule recordings of shows and again when recordings are made, but ultimately recordings are scheduled by time and the guide is only used as available. The third thing I learned is that I could still set up recordings by time even if the guide was gone, which is good to know.
 

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Quote:
Originally posted by buzgz
This would mean that you have noise on the line much greater than the noise introduced by the box...

In other words, what I said. Of course, if in your world splitters, fittings and long cable runs are unlikely sources of line interference, YMMV.
 

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Quote:
Originally posted by frankz1
In other words, what I said. Of course, if in your world splitters, fittings and long cable runs are unlikely sources of line interference, YMMV.

Frank, I don't understand YMMV, but I'd bet it's not complementary. It is, of course, entirely possible that line noise exceeds box noise in some cases. I'd also bet that it is rare. We started this discussion for a situation where only one channel showed break-up. In those situations, the probabilities vastly favor box noise as the culprit. Otherwise, both channels would show break-up. I'd bet both of your channels showed break-up when you had the problem. That's because your problem was clearly noise on the line.


Do the experiment (removing the splitter), post the numbers before and after, and we'll discuss the results. I'm a rocket scientist, not a debater. I'll level with you if I'm wrong, and I expect the same from you. After all, we're here to help each other.
 

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Quote:
Originally posted by buzgz
Frank, I don't understand YMMV, but I'd bet it's not complementary. It is, of course, entirely possible that line noise exceeds box noise in some cases. I'd also bet that it is rare. We started this discussion for a situation where only one channel showed break-up. In those situations, the probabilities vastly favor box noise as the culprit. Otherwise, both channels would show break-up. I'd bet both of your channels showed break-up when you had the problem. That's because your problem was clearly noise on the line.


Do the experiment (removing the splitter), post the numbers before and after, and we'll discuss the results. I'm a rocket scientist, not a debater. I'll level with you if I'm wrong, and I expect the same from you. After all, we're here to help each other.

YMMV = Your Mileage May Vary


I turn my box off for no man, but next time a crash requires it I will do said "experiment."


You're a rocket scientist? Funny, I'd have pegged you for a brain surgeon.
 

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I've had most of the mentioned issues once or twice:


Freezing on a channel that is cleared by switching channels. Happened several times on one day on one channel. Happened again a couple days ago on a different channel.


One or two spontaneous reboots causing a gap in a recording (two items in My DVR).


HD picture breakup. Happened once just watching live. Happend again when recording 2 HD programs and watching a third previously recorded one (stress that puppy good). One of the recordings had a ton of breakup (Las Vegas) as well as 10 missing minutes near the beginning. The other recording (24) was flawless, as was viewing the pre-recorded program, so I'm leaning towards it being the station, not the box.


Series recording - bleah. I've figured out which ones work and which ones don't and the latter (about 30%) get done manually.


I tell ya - it's a good thing we don't watch that many shows, since I can't imagine recording our prime time shows in anything other than HD anymore - it's just too pretty.


Bob Scott
 

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Quote:
Originally posted by rkhobbit
Thanks! Yes that crossed my mind too. It's $5/month for an extra STB. I'll use it as a last resort...


I PM'd the AVS member who did this exact 6412 setup with a ReplayTV and he indicated it works great.

I don't see any need to use a second cable box to be able to record on a Replay/TiVo. I use my old Showstopper/Replay to record SD programs and mostly save the 6412 for HD. The setup required feeding the cable signal to both the 6412 and the Replay; I also run the cable feed into the antenna input of my TV. I run the s-video out from the 6412 into to Replay, and the DVI output of the 6412 to the TV. The Replay is setup to understand that it has separate inputs (it lists the direct cable inputs as 1002, 1003, etc. and the cable box inputs as 501, 502, etc., and automatically switches to the correct input when recording). I use an ir-blaster from the Replay to the 6412 for times when I record off the 6412, which is infrequent. Mostly we record analog channels on the Replay that are not broadcast in HD, and these recordings do not involve the 6412. If we do record from the 6412 on the Replay, I am careful that we are not recording on both 6412 tuners at the same time. The ir-blaster tunes the 6412 to the correct channel and records it. Instead of using too many splitters, I use a 1-to-4 bi-directional antenna amplifier, about $50 at Radio Shack. It allows signals through in both directions, so VOD still works.
 

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Quote:
Originally posted by cgw
I don't see any need to use a second cable box to be able to record on a Replay/TiVo. I use my old Showstopper/Replay to record SD programs and mostly save the 6412 for HD. The setup required feeding the cable signal to both the 6412 and the Replay; I also run the cable feed into the antenna input of my TV. I run the s-video out from the 6412 into to Replay, and the DVI output of the 6412 to the TV. The Replay is setup to understand that it has separate inputs (it lists the direct cable inputs as 1002, 1003, etc. and the cable box inputs as 501, 502, etc., and automatically switches to the correct input when recording). I use an ir-blaster from the Replay to the 6412 for times when I record off the 6412, which is infrequent. Mostly we record analog channels on the Replay that are not broadcast in HD, and these recordings do not involve the 6412. If we do record from the 6412 on the Replay, I am careful that we are not recording on both 6412 tuners at the same time. The ir-blaster tunes the 6412 to the correct channel and records it. Instead of using too many splitters, I use a 1-to-4 bi-directional antenna amplifier, about $50 at Radio Shack. It allows signals through in both directions, so VOD still works.

Thanks CGW!


I like the idea of using a RF splitter on the cable for non-digital channel recording on the Replay (TiVo in my case) and then using the 6412 via S-Video for recording non-HD digital channels greater than 100.


I'm getting closer to pulling the trigger and switching from DirecTV to Comcast cable.
 

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Quote:
Originally posted by rkhobbit
While watching HDTV live via DVI out from the 6412 on an HDTV, does the 6412 also simultaneaously downconvert the live HD TV signal to 480i for output to either/both the S-Video or composite outputs?

Yes, the composite out and S-v outs work concurrentlly with the HD output, but when the 6412 is set to output at HD resolution, the menus and the guide will not be seen on monitors receiving the SD pictiure via the composite or S-v. out from the 6412. So you get the same picture and audio via composite or S, just not the graphics (menus, guides, VOD menus, setup menu)
 

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Quote:
Originally posted by QZ1
Did you buy the amp from the Cable co. or did you buy your own?

What amp did you get?

Anybody else who bought an amp, please respond.

I bought one at SmartHome, a 1GHz RF Bi-Directional Amplifier, item # 7771 for $60. I actually have two of them. No problems so far.


Jack
 

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Quote:
Originally posted by rkhobbit
While watching HDTV live via DVI out from the 6412 on an HDTV, does the 6412 also simultaneaously downconvert the live HD TV signal to 480i for output to either/both the S-Video or composite outputs?

Yes, all outputs are active simultaneously.
 

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Quote:
Originally posted by kwkarth
Yes, all outputs are active simultaneously.

Thanks... That's good news since I may modulate the composite output from the 6412 for whole house distribution via a Channel Vision RF modulator.
 

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Quote:
Originally posted by rodneyremington
I have a samsung DLP too connected to a 6412 via component. (I also have a sony plasma connected to a 6412 via DVI).

I agree with the suggestion that you go into the service menu on the 6412 and make sure your aspect ratio is set at 16:9. I would set it at 1080i .

Thanx, I will try to do that as soon as I get home. I was sorely disappointed when my brother slammed me for poor HD quality. Analog channels look so poor does anyone have any suggestions for fixing them? Just so darn grainy...my regular box paired with a crt sony trinitron look much better.
 

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Quote:
Originally posted by rkhobbit
Thanks... That's good news since I may modulate the composite output from the 6412 for whole house distribution via a Channel Vision RF modulator.

There is an RF output already on the 6412. You could just use that and feed it to a distribution amp.
 

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Quote:
Originally posted by Demianwulf
Thanx, I will try to do that as soon as I get home. I was sorely disappointed when my brother slammed me for poor HD quality. Analog channels look so poor does anyone have any suggestions for fixing them? Just so darn grainy...my regular box paired with a crt sony trinitron look much better.

You might try setting the DVI and Component outputs to 720p to see if that works better than 1080i. I think your Samsung uses 720 horizontal lines, so setting the 6412 to 1080 might cause an hd program broadcast in 720 to be upconverted to 1080, and then your set would just downconvert it to 720. Often, less processing is better. I don't know the native resolution on the Sony plasma; most of the Sony rear projection lcd sets use 788 lines. It is worth a little experimenting to see if it matters.


Re RF output - my 6412 does not have one.
 
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