Phoenix, AZ - HDTV - Page 7

You can get the 1ghz from Rat Shack, Home Depot, Lowes and other places. I have Cox highspeed internet and I tried scanning for the hd locals from a outlet in my living room but the scan found no channels. I guess you have to use the spliter at the outlet that the cable modem works on. My cable modem is in the bedroom so I'll have to run the split from there to the living room.

I get a couple low channels and a couple high channels but nothing else, which makes my think they used a bandpass for the broadband. But I really don't care, as they have nothing analog that I can't get somewhere else. I might try their HD pak for a short time, but I'm not expecting much from that either. It's kind of high for what you get if you already can get OTA HD locals. My HD Tivo wouldn't be able to take advantage, anyway.

As far as the HD locals, they start with OTA quality, and it can only go downhill from there. I might be surprised (I would be surprised) if their HD quality was as good as OTA, but it might be. I know folks who have the HD pak and like it (PQ). One guy I know says they even have a daily email letting him know everything that will be in HD that night, which is pretty cool.

HD quality shouldn't be a concern since it's either get it or lose it. Unlike analog signal, HD only has stability issue. As long as Cox signal is stable (must be more stable than antenna), HD picture quality should be the same as OTA and any other HD sources.

DoubleDAZ, Well, the COX signal that came into my house was never clear. Even with "boosters" as COX puts on the line to help the impedence of the cable. I notice SIGNIFICANT differents channels delivered by DirecTV and COX. Even the locals look clear.

THanks for the reply.

Regards,
Jim

Folks, thanks to all your info. I tried connecting Cox cable to my Mitsu HDTV tonight. What do you know, it did decode the HD channels starting from cable channel 76 which happens to be channel 10. I got 10, 8, 5, 12, 15, 61. Channel 3 and 45 are not there. So now I am about done. Analog cable, HD channels and internet all work from one good old RG6 cable feed.

What Mitsubishi TV do you have? I may have to try and try this hook up. I am getting the locals OTA but I get alot of interference since I'm using an indoor antenna.

I agree with Dave. Over amplification is as bad as weakening the signal. Let me give you an example. This whole idea of me trying to get HD channels from Cox cable feed was because I couldn't get a good reception from my OTA antenna in the first place. Last night after I successfully connected Cox cable to my Mistu TV, I tried my old antenna input again just to compare PQ. To my suprise, almost all HD channels showed up this time (only 45 did not). I could not understand first, then I realized that I took a 2-way split power amp away that I used to use right behind the TV to feed analog antenna input and HD ant input. I did a quick test of reusing the split amp. Channel 61 disappeared. The antenna in my 2nd floor attic goes through 3 stages of amplification. I think that's my problem all along. I simply don't know it. Cox technical support also confirmed this when I called them yesterday asking about the concern on splitting the cable. He said in most cases a simple spliter is fine and don't over amplify the signal. More is not always better.

BTW, Dave, my Mitsu TV is WS65813. I checked Mitsu product catalog. All of their HDTV models with built-in ATSC tuner are also equipped with a QAM cable tuner.

[i]I agree with Dave. Over amplification is as bad as weakening the signal. Let me give you an example. This whole idea of me trying to get HD channels from Cox cable feed was because I couldn't get a good reception from my OTA antenna in the first place. Last night after I successfully connected Cox cable to my Mistu TV, I tried my old antenna input again just to compare PQ. To my suprise, almost all HD channels showed up this time (only 45 did not). I could not understand first, then I realized that I took a 2-way split power amp away that I used to use right behind the TV to feed analog antenna input and HD ant input. I did a quick test of reusing the split amp. Channel 61 disappeared. The antenna in my 2nd floor attic goes through 3 stages of amplification. I think that's my problem all along. I simply don't know it. Cox technical support also confirmed this when I called them yesterday asking about the concern on splitting the cable. He said in most cases a simple spliter is fine and don't over amplify the signal. More is not always better. [I/]


Simple, more gain = more noise, unless you really need an amp, don't use it. I'm 20 miles as the crow flies to South Mtn and have a Winegard GS-2200 (Sensor II) that was provided by Voom for my install and there is no amp inline, it's been cut-out and my signal levels at the STB are all above 90 on both my Voom boxes and my Sony Hd200 box.

I'm an RF systems engineer that uses amps in receiver networks for commerical and police 2-way radio and the goal of the amp is not to amplify the signal, it's to make up for the loss of the coax and connectors to get back up to 0db gain or unity.

It's a tough lesson to grasp but more is not better in RF.

Miguel

lombana,

I use amps for the purpose of compensating for the loss by lengthy cable run. Since you are a RF guy, may I ask you a stupid question - how many feet of cable run we should add amp? Add amp at the antenna or near the TV end?
Thanks.

You need to determine the loss of the cable for the length of the run that you have, calculators are available all over the web for different coax types which may have more or less loss depending on the type. Here is one that I've used in the past: http://www.ocarc.ca/coax.htm

Next you need to measure the signal at the antenna to see how much gain you need to get that same amount at the end of the coax. You also need to know the gain of the amplifier you're using.

Finally, if you amplify the signal at the end of the line you're adding gain to the noise, ideally you need a 2 part amp / pre-amp system, where you would add the gain at the sending end or the antenna and you might need attenuators on the receiving end to null out the line a bit.

I had an experience in Orlando, my former home, where my Channel Master 7000 series amp (great for HD btw), was killing my signal. In that situation I was about the same distance to the towers as I am here in Phoenix, I experiemented with 6db of attenuation in-line and finally settled on 9db to the signals in order. I didn't have the luxury of a network analyzer at that time to mesaure the signal at the input of the antenna so there was some guess work, but reality the 30db of gain from the CM7xxx was too much.

Here are some basic numbers as an example:
100' RG-6 on Vhf Channel 7 (175mhz) has an inherent loss of 3.6db
100' RG-6 on Uhf Channel 45 (650mhz) has an inherent loss of 7.3db

Take this into consideration when designing an amp system and you'll have a better quality signal going into your receiver without overdriving the unit.



Miguel

Very good technical info, thanks, Miguel.

Very true, although more accurately, more gain in and of itself does not equal more noise. More stages of amplification generally can create more noise, especially if the amp does not have a high noise figure, but any amp will add some noise. And operating an amp with a low input signal (below the optimum window of operation) can indeed mean more noise.

But your arguments are sound.

Is anyone keeping tabs on the local broadcasters now that the 1st round of channel elections for DTV carriers has passed? I was just curious to know if anyone knew about any upcoming changes in the works for the local Phoenix stations via their filings with the commission. I tried to query the FCC database however was unable to pull Tv stations, if anyone has a trick or has knowledge of the elections for this region, let us know.

Please define "DTV channel elections".

Wasn't sure.

Typically, stations with originally low V's (3 and 5) or high U's (45 and likely 61) will stay with the new channel, which typically is technically a better choice and provides better coverage. Original high V's (8, 10, 12) will very likely want to end up back there again instead, for exactly the same reason.

Low V's have a lot of impulse noise interference, which can cause pixellation breakups especially in fringe areas. High U's are more difficult to maintain, and typically don't have the coverage of lower U's or high V's. Low U/high V stations can usually use solid state transmitters. High U's need tubes and more operating power for similar coverage. As examples of such strategy, KSAZ (10/31) will move back to 10, while KUTP (45/26) will stay with 26.

There was a recent filing deadline, which is why we are seeing this just now.

Yep that's exactly what I was talking about ... since the elections were due to the FCC on the 27th of January all stations in the top markets should have filed a new license for their requested or election frequency. In most markets the UHF channel is prevailing and many are dumping the VHF allocation, plus it makes it easier on the viewers if you only need 1 band of antenna, then with the advantage of the PSIP channel mapping, they can still call themselves by their old channel until the end of time as long as they are on the right broadcast frequency. I was just curious to know if anyone knew what the PHX stations were up to with this, I couldn't find a way to query the FCC database for TV only FM, Ham, Police etc...

Miguel

Just to confirm what everyone else is posting, I was able to achieve this this weekend. No matter what I tried, I could not get KPHO over the air. I do get cox internet, but not cable. I split off the feed coming into my cable modem and plugged it into the back of my QAM capable TV, and voila -- grammys in high def last night!

Anyone live in Maricopa? I am thinking of making a move down there w/in the next 6 months or so, and I was wondering what the OTA locals situation is like. I'd imagine it's a pretty strong, clean signal since there's nothing that would seem to be an obstruction between the town and South Mountain.

I've got Voom and an old DirecTv SatHD200 box serving my home and all the local digital channels are solid on both sets of boxes in my home. I'm about 20 miles as the crow flies from the antenna farm at South Mtn and would say that you're not going to be dis-appointed.

3.1 Phoenix Local Indy (24)
5.1 CBS HD (17)
8.1 PBS HD + .2 + .3 (29)
10.1 FOX HD (31)
12.1 NBC HD (36)
15.1 ABC HD + .2 + .3 SD (56)
21.1 Religious Programming
33.1 Spanish (34)
33.2 Spanish (34)
45.1 UPN (26)
51.1 PAX (52)
61.1 WB (49)

If this helps you a little before you get here...
MIGUEL

I thought that I saw some programs also being broadcasted in HD on 61.1 WB (49)?

Don

Well you're lucky b/c I tried the same thing on Saturday and I could not get the hd locals from Cox. I have their highspeed service and when I called customer service the girl tried to tell me that I needed to sub to the 49.99 internet package in order the get the hd locals. I currently have the 24.99 highspeed service and splitting the cable at the outlet that the modem is on didn't get me the results that I wanted.

Yes, you are correct. As a matter of fact I watch the Gilmore Girls and One Tree Hill in hd on the 61.1. Two weeks from now I'll also be watching new episodes of Summerland in hd on 61.1 so there is a wide range of hd programming on 61.1.

Miguel is correct, you shouldn't have too much of a problem getting the OTA hd locals depending on the placement of your antenna. I use a antenna that sits on top of my tv connected to QAM tuner and I live about 17 miles from the antennas and I'm able to get all of the stations.

Thanks. I live in Chander right now, so I'm getting OK reception, but that's an issue w/ how I am situated. Just wanted to make sure there weren't any issues down there. Just another factor in my home buying.

Did anyone have audio issues w/ Lost last night? It kept dropping in and out. Happened about 20 times during the epsiode.

OTA, Cable, or Sat???

Sorry. I meant tonight.

OTA. Picture was fine, but I kept getting audio drop out for 5 seconds at a time at least 20 times.

Ryan at ABC15 said that they were testing the new DD equipment so it may be afew days before they get the audio glitches worked out. The picture problems seemed to be resolved though.

Darn Dave...you are too fast for me...

Ok. Thanks for the heads up guys. I appreciate. it.