Analog Reception Woes...

Jeff Harrison · 10-27-2005, 12:58 PM

I need some diagnostic help. I live in Livermore, Ca 94551 (about 45 miles eas of San Fran, 30 miles north of San Jose). I have been stuggling with anlog tv reception on a few key SF stations (2-FOX, 4-KRON, & 5-CBS). Here's a comparison of my current analog VHF reception:

2 FOX - Very poor
4 KRON - Pretty poor
5 CBS - Better than 2 & 4, but not still not good
7 ABC - Excellent
9 PBS - Excellent

I have attached a link with snapshots of the reception for both 2-FOX (the worst) & 7-ABC (the best). The frustrating thing is that these stations are all broadcast from the SAME TOWER! Given that my reception for 7 & 9 is so good, I am thinking that my problems with 2,4, & 5 have more to do with interference than a weak signal. I have tried several antennas (Channel Master 3016, 3018, 3020 & AntennasDirect V21) and preamps (CM Spartan3 & Winegard AP-8275). No one antenna does particularly better than the others, even the huge 3020. The irony is that the little 3016 quite frankly does as well as the bigger models, even though I am about 45 miles from the tower.

I am starting to think that I am just wasting my time trying different antennas. It seems to me that there is just something more fundamentally wrong with those channels. I know that low-band vhf is succeptible to interference, so I've tried a high-pass RF filter from Radio Shack, but it didn't appear to do anything. I also tried a ferrite core choke, but again, no improvement.

One other potentially significant piece of information; sometimes when I am playing around with the coax connections, the picture on channel 2 looks good for a fraction of a second before it gets bad (i.e. when I am connecting the coax to the amp power supply or the tv, when I first touch the mating connectors together and/or wiggle them around a bit before screwing them together, the picture seems to improve for an instant). It's not any one connection in particular, and remember than 7 & 9 are great, so I don't think it's a problem with my coax or connectors. More likley, it seems, for that fraction of a second I am receiving a good signal without all of the noise and/or interference. I have also tried taking a small antenna up on the roof and using a fairly short piece of coax, and the picture is about the same, so I also don't think that it is any general signal loss in the cabling either.

Well, what do you guys think? Any suggestions, tips, tricks? Any noise filters, interference contraptions, other devices I could consider? Am I barking up the wrong tree? Any advice, suggestions, or comments are much appreciated. Please don't be shy. I have also started playing around with digital reception (usinga a CM 4228), and it looks promising, but ultimately I would like to be able to get both analog and digital reception.

Thanks!

http://www.iharrison.com/antennas.html

mjcan · 10-28-2005, 04:55 PM

Jeff:

- How the heck did you get pixilation on an analog station? (Camera?)

- Any-who I have had problems getting Syracuse channel 3 for years now, I believe it is adjacent channel or the same channel, (from another city), giving me trouble. I have no suggestions, couldn't improve mine either.

Mike

jim5506 · 10-28-2005, 10:14 PM

I think your best bet is to go digital with the CM4228 and the CM7777 or similar pre-amp.

Your low band analog stations are very prone to interference, and as far away as you are that's what you are getting. That picture of KTVU (FOX) is interference.

Digital counterparts of the analog's you want are broadcasting at full power (1,000KW) in UHF. You'll probably have more luck there, and why invest time and money in a dead horse?

mjcan · 11-04-2005, 06:32 AM

I recently changed to RG-6 cable rather than the pre made 50' Radio Shack stuff, (RG-59?). The Radio Shack stuff has been the reason why I have been having trouble getting Syracuse channel 3. Now Syracuse 5, and 9 come in good too. I would never believed changing coax would make such a difference. Could coax be your problem?

10-27-2005, 12:58 PM	#1
Jeff Harrison My plasma is High Def. Join Date: Jul 2005 Posts: 7	Analog Reception Woes... I need some diagnostic help. I live in Livermore, Ca 94551 (about 45 miles eas of San Fran, 30 miles north of San Jose). I have been stuggling with anlog tv reception on a few key SF stations (2-FOX, 4-KRON, & 5-CBS). Here's a comparison of my current analog VHF reception: 2 FOX - Very poor 4 KRON - Pretty poor 5 CBS - Better than 2 & 4, but not still not good 7 ABC - Excellent 9 PBS - Excellent I have attached a link with snapshots of the reception for both 2-FOX (the worst) & 7-ABC (the best). The frustrating thing is that these stations are all broadcast from the SAME TOWER! Given that my reception for 7 & 9 is so good, I am thinking that my problems with 2,4, & 5 have more to do with interference than a weak signal. I have tried several antennas (Channel Master 3016, 3018, 3020 & AntennasDirect V21) and preamps (CM Spartan3 & Winegard AP-8275). No one antenna does particularly better than the others, even the huge 3020. The irony is that the little 3016 quite frankly does as well as the bigger models, even though I am about 45 miles from the tower. I am starting to think that I am just wasting my time trying different antennas. It seems to me that there is just something more fundamentally wrong with those channels. I know that low-band vhf is succeptible to interference, so I've tried a high-pass RF filter from Radio Shack, but it didn't appear to do anything. I also tried a ferrite core choke, but again, no improvement. One other potentially significant piece of information; sometimes when I am playing around with the coax connections, the picture on channel 2 looks good for a fraction of a second before it gets bad (i.e. when I am connecting the coax to the amp power supply or the tv, when I first touch the mating connectors together and/or wiggle them around a bit before screwing them together, the picture seems to improve for an instant). It's not any one connection in particular, and remember than 7 & 9 are great, so I don't think it's a problem with my coax or connectors. More likley, it seems, for that fraction of a second I am receiving a good signal without all of the noise and/or interference. I have also tried taking a small antenna up on the roof and using a fairly short piece of coax, and the picture is about the same, so I also don't think that it is any general signal loss in the cabling either. Well, what do you guys think? Any suggestions, tips, tricks? Any noise filters, interference contraptions, other devices I could consider? Am I barking up the wrong tree? Any advice, suggestions, or comments are much appreciated. Please don't be shy. I have also started playing around with digital reception (usinga a CM 4228), and it looks promising, but ultimately I would like to be able to get both analog and digital reception. Thanks! http://www.iharrison.com/antennas.html

10-28-2005, 04:55 PM	#2
mjcan High Definition is the definition of life. Join Date: May 2005 Posts: 52	You got pixilation, maybe you got a pixie? Jeff: - How the heck did you get pixilation on an analog station? (Camera?) - Any-who I have had problems getting Syracuse channel 3 for years now, I believe it is adjacent channel or the same channel, (from another city), giving me trouble. I have no suggestions, couldn't improve mine either. Mike

10-28-2005, 10:14 PM	#3
jim5506 Yellow Submarine Join Date: Dec 2004 Location: Lubbock, Texas Posts: 2,416	I think your best bet is to go digital with the CM4228 and the CM7777 or similar pre-amp. Your low band analog stations are very prone to interference, and as far away as you are that's what you are getting. That picture of KTVU (FOX) is interference. Digital counterparts of the analog's you want are broadcasting at full power (1,000KW) in UHF. You'll probably have more luck there, and why invest time and money in a dead horse? Last edited by jim5506; 10-28-2005 at 10:17 PM.

11-04-2005, 06:32 AM	#4
mjcan High Definition is the definition of life. Join Date: May 2005 Posts: 52	Type coax made a big difference. I recently changed to RG-6 cable rather than the pre made 50' Radio Shack stuff, (RG-59?). The Radio Shack stuff has been the reason why I have been having trouble getting Syracuse channel 3. Now Syracuse 5, and 9 come in good too. I would never believed changing coax would make such a difference. Could coax be your problem?