Failed antenna install. Need advice.

[newsposter]

Note I want WB/UPN so waiting for the HDdvr doesn't help me right now.

local installer ($60 per hour) that I hired to put the DB8 that I previously bought on the chimney won't be back in the office until Monday so I wanted my options before then. I had it in the attic but couldn't get in fox (uhf 42) because it was 2 degrees off. I figured if I got 75-90 in the attic on the other nets, (except 54), that on the chimney would be a good compromise to get in fox because in theory the signal is stronger outside right?

Well after much fiddling, we got it to where ch 42/54/64/67 were all pretty solid 60-70. Thing is, even when he was fiddling outside, i never got 64/67 to as good a signal as I had in the attic. I guess this was more of a big deal than I thought at the time. Does it sound reasonable that because the chimney was actually 6-8 ft away from the site in my attic, that it may be the reason I never got in a good signal outside? I'm assuming the antenna is perfectly plumb but of course I have no way of telling. He did seem to take great care when he did the chimney mount.

So overnight we had a very bad thunder storm. however this morning all the channels were the same as yesterday. Then this afternoon the winds and rains kicked up and the channels were all unwatchable during the storm (going from zero up to 70 wildly). Even now that it's calmed down, i can't get back in ch 67 but the others are relatively ok. I'm assuming this means the antenna moved. I didn't think up high on a 10 ft pole was very stable but he assured me it was rock solid. Obviously this isn't true.

So i have to think of my options and it's frustrating

1. tell him the antenna moved and make them somehow shore it up. I'd assume they would have to do this free/reduced cost since it obviously moved. However the problem I have this this option is even at the time of install, i only got low 70s for a high signal when inside i was getting 80s. So this may be foolish to try and solidify an antenna in this relatively poor position.

2. maybe lower the antenna on the 10ft pole down a few feet to make it more stable? Or is this pointless given my 'weak' signals of 60-70?

3. I'm assuming you can do a tripod mount on the peak of any roof. (didn't ask him but i'd assume they can do that). I could have him stand near the spot where I had the good signals inside and try to find a good signal and I'd assume they should be the same/stronger on the roof at that point. Then we can determine how ch 42 will come in at that point. I'd assume they would do this as they are the pros and i dont see how else you could tell a good signal. Also if they can't get in all 6 networks, I may as well put the antenna back inside away from the elements.

4. try to lower the antenna for more stability and just aim for channel 42 then put another antenna back in the attic and get another antenna (though I know it's a 2 week wait for a jointenna unless I can do something like a reverse splitter? Of course then there's the cost for another antenna plus 30 for the jointenna. And now i'm really paranoid about outside mounts not being stable.

5. ask them what antenna they have for my area (I know the like wineguard) and ask him to do a test of it on the chimney mount.


I already spent 200 on friday. I dont know how much more I want to put into this. I definitely have to have him back here, even if just to take the antenna down, as I dont climb on roofs. My gut says have him use a tripod and at least try to move the antenna to a point where the signal is at least as strong as inside and get the antenna as low to the roof as possible to minimize wind problems. I guess the 6 ft to the one side made a big difference.

[NatasNJ]

I am about to try and go the OTA route and am in the same area as you. I think I am going to pull the trigger on the HDTV upgrade through Directv but if I can't get all my Locals in HDTV via OTA then I will bail from it. I want to stick to Directv but I can't validate the upgrade costs if I can't get all my loals in from the OTA now.

Wish me luck. According to the antenna websites I am 13 miles from the HDTV towers and they are all in pretty clear site from my house. So I am hoping/assuming I will be ok. We will see.

[A J Ricaud]

It may very well be that the antenna moved due to the wind but I would also suspect the coax connection. It mat not be screwed in tight enough and/or a waterproof (compression) type connector was not used. Also, was a good quality RG6 coax used to minimize loss?

The antenna moving due to wind can probably be fixed by using guy wires to secure it so it doesn't turn or whip around. It is possible that the new location is responsible for lowering the signal/bit rate but is sounds unusual. Going from an attic to a roof mount almost always results in a better quality signal. Odder things have happened though.

Once everything is stable an amp. can increase the signal if more is needed. As for the DB8, it, along with the CM4228, are 2 of the best going.

[TyroneShoes]

...couldn't get in fox (uhf 42) because it was 2 degrees off...in theory the signal is stronger outside right?...i never got 64/67 to as good a signal as I had in the attic...I'm assuming the antenna is perfectly plumb...2 degrees should not make a difference, even with a very directional antenna such as the DB8. Simply peak for the worst channel, and hopefully that will not degrade the others. Plumb is not important, as the V/H axis is not that different for the polar pattern of the antenna. It may just be that you are in a negative node at the location the antenna was placed, and may have been in a positive node in the attic. All things being equal, the signal will be attenuated and reflected slightly more inside an attic, but placement could be even more critical, especially in rough terrain, which creates stronger nodes....I didn't think up high on a 10 ft pole was very stable but he assured me it was rock solid. Obviously this isn't true...

maybe lower the antenna on the 10ft pole down a few feet to make it more stable? Or is this pointless given my 'weak' signals of 60-70?...if they can't get in all 6 networks, I may as well put the antenna back inside away from the elements.

4. try to lower the antenna for more stability and just aim for channel 42 then put another antenna back in the attic and get another antenna (though I know it's a 2 week wait for a jointenna unless I can do something like a reverse splitter? Of course then there's the cost for another antenna plus 30 for the jointenna...

5. ask them what antenna they have for my area (I know the like wineguard) and ask him to do a test of it on the chimney mount...If the mast is guyed properly, lowering the antenna should not improve stability or reception. Maybe the attic is just better. A noble experiment to mast-mount, that just didn't pan out. Instead of picking the obvious or easiest place to mount the antenna, good installers walk the roof and pick the spot with the best reception.

The jointenna solution will only work if you are splitting the frequency bands properly, and that means all channels on either antenna must reside in a band separate from those on the other. Even when this is practical, it may not really work out for you.

The DB8 is probably the best choice for UHF above CH 55. The 4228 might be slightly more directional, but probably not significantly so, so I would stick with the DB8. Maybe it's time for an amp, and/or an FM trap, depending upon how far away you are and whether there is strong FM coming from the same place. In my case, both helped improve signal quality readings for all channels.

One compromise solution is to peak for UPN/WB, and get the others from DBS.

[newsposter]

It may very well be that the antenna moved due to the wind but I would also suspect the coax connection. It mat not be screwed in tight enough and/or a waterproof (compression) type connector was not used. Also, was a good quality RG6 coax used to minimize loss?

The antenna moving due to wind can probably be fixed by using guy wires to secure it so it doesn't turn or whip around. It is possible that the new location is responsible for lowering the signal/bit rate but is sounds unusual. Going from an attic to a roof mount almost always results in a better quality signal. Odder things have happened though.

Once everything is stable an amp. can increase the signal if more is needed. As for the DB8, it, along with the CM4228, are 2 of the best going.

I know for sure all my rg6 was ok, because that part in the attic etc remained stable with the amp etc. The guy added 30 more feet of new cable onto my amp and put new ends on. They do look like the heavy duty type, if that's the term. Also, today during the storm i took some other RG6 and ran right from the attic down my steps to the HDtivo. That cut out about 75 ft of cable. Still the same results. So length isn't the issue.

I agree "guys" would make sense if i were to keep it in the location, but i kid you not, he told me he was moving it about 1/8 inch at a time and that made all the difference in the compromise in the 2 degrees i need to resolve. So my feeling is, in it's current location, it literally would have to be solid 100%. Somehow that doesn't sound do-able in the realm of high winds etc. And even if it was, it's only a 70 signal at best. With most mid 60s.

And 6 ft does make a difference here, at least in the attic. What I had done is set up a pipe with my DB8. Then i nailed in about 10 different nails on hi/low parts of the rafters in the attic. It was over a spread of about 8 ft left to right. Well huge differences within those 8 ft moving the antenna around. I have a feeling i'm shooting between a house and some other objects that i can't see. The guy on the roof said he saw nothing obviously blocking the signal and i'm so far from the neighbors house, it shouldn't be an issue (80 ft at least)

So my guess is, i need to move to the same position that i was at inside the house. While i was in the attic, only moving up the antenna 6 inches got me from a 71 reading to a stable hi 80s. Therefore, if i could just pop open the roof, i had assumed i'd get 90s and thus be able to rotate the 2 degrees to get my difficult uhf 42.

So i guess my only real option, if i'm going to have to mount outside is i'll see if they will come out and stand there and 'play' with the antenna left on the roof 6 ft to its in attic location then mount it on a tripod. Or else put it back in the attic and fork over more money for an antenna for ch 42 plus a jointenna. I know i'll pay either way and dont care as long as it's the desired result.

[TyroneShoes]

...I agree "guys" would make sense if i were to keep it in the location, but i kid you not, he told me he was moving it about 1/8 inch at a time and that made all the difference in the compromise in the 2 degrees i need to resolve. So my feeling is, in it's current location, it literally would have to be solid 100%. Somehow that doesn't sound do-able in the realm of high winds etc...
A 10 ft. mast with a light antenna will only move 1/8" or so if you try to move it. But that is anunguyed mast. A guyed mast will not budge one millimeter. Also, high winds will make an unguyed antenna twist, like a stopsign in a high wind. This is death to signals received from a highly-directional antenna. It is starting to sound like your installer is feeding you a line of BS, and is not motivated to do a good job, just to improving his kids' college fund.

[newsposter]

2 degrees should not make a difference, even with a very directional antenna such as the DB8. Plumb is not important, as the V/H axis is not that different for the polar pattern of the antenna.


good to hear, i wont yell at him for not bringing up a level lol. I guess something really is blocking the upper uhf then.

. Maybe the attic is just better.

me thinks you are right. I have no clue what 'nodes' means but i'm 'positive' i'm in the negative :) - bad pun- I know the attic (or at least 6ft to the left of the chimney) is better. And I also dont think i'd be happy with even a 100% stable mast with just 60-70 signal. It scares me having no wiggle room with mother nature.

A noble experiment to mast-mount, that just didn't pan out. Instead of picking the obvious or easiest place to mount the antenna, good installers walk the roof and pick the spot with the best reception.

in fairness I called and requested the chimney mount. They did ask a bunch of questions on the phone. But as you said below, they really could have spent the extra hour it took to aim it, walking on the roof trying better spots. I'll absolutely demand that next time. Or no mounting at all outside.

The jointenna solution will only work if you are splitting the frequency bands properly, and that means all channels on either antenna must reside in a band separate from those on the other. Even when this is practical, it may not really work out for you.

I dont know what bands means. Isn't the fact that ch 42 is 2 degrees off all the rest, has a super low antenna height and low power enough to warrant a separate antenna? I'm lost in this area

Maybe it's time for an amp, and/or an FM trap, depending upon how far away you are and whether there is strong FM coming from the same place. In my case, both helped improve signal quality readings for all channels.

my amp from home depot was better than his preamp. I have tried with trap on and off and no difference.

One compromise solution is to peak for UPN/WB, and get the others from DBS.

unfortunately, i really want '24' in HD and since there's no DVR yet, i'm stuck getting fox from the antenna yet but did think about your option once they get them in. UPN is always a solid 90 (ch 32) and WB is a tolerable 65ish. (ch54) And incase i didn't say it, i was very happy with all channels but fox when this was in the attic. So i'm really moving it outside for just one channel.

[newsposter]

A 10 ft. mast with a light antenna will only move 1/8" or so if you try to move it. But that is anunguyed mast. A guyed mast will not budge one millimeter. Also, high winds will make an unguyed antenna twist, like a stopsign in a high wind. .

I witnessed this today. it wasn't huge, but i did notice the antenna moving even with the naked eye. I guess I shouldn't have signed the darn work order with only such crappy signals. That wont happen again thats for sure. I was just thrilled they all came in.

[TyroneShoes]

...I dont know what bands means. Isn't the fact that ch 42 is 2 degrees off all the rest, has a super low antenna height and low power enough to warrant a separate antenna? I'm lost in this area...

"24" is good motivation to solve your problem, IMO (last year it was the best show on TV).

I can give you an example of what I meant by bands. Lets say you are receiving ch 35 and ch 45 from 100 degrees, and ch 55 and ch 65 from 145 degrees. You could then employ a jointenna with a frequency split at about ch 50, which would effectively isolate one antenna from the other. The antenna pointed at 100 degrees would allow ch 35 and 45 but any signal received by the other antenna, at those frequencies pointing at 145 degrees, would be filtered out, so off-axis signal (multipath interference) at those frequencies would not make it to the tuner. And vice versa for 45 and 55 on the other antenna.

But if you were receiving 35 and 55 from one direction and 45 and 65 from the other, there is no practical way to separate the bands between antennas. If you can't do that, connecting two antennas together just destroys any directionality, and with it, any rejection of interference.

Again, 2 degrees is not significant to warrant separate antennas, nor is the station's antenna height (unless you are blocked). The most-directional antenna out there should handle at least a swath of 20 degrees or so, maybe more. Aim for the weakest station in the group, and the rest will fall into line.

[newsposter]

Again, 2 degrees is not significant to warrant separate antennas, nor is the station's antenna height (unless you are blocked). The most-directional antenna out there should handle at least a swath of 20 degrees or so, maybe more. Aim for the weakest station in the group, and the rest will fall into line.

well thanks for the detailed explanation and saving me 40 bucks for a jointenna plus cost of another antenna. I was seriously going to try it in the attic.

And I guess this is an oxymoron here because everything thats supposed to happen,is being opposite. higher=worse etc. Aiming at the weakest doesn't get me the others

When ch 42 was in pretty solid on the roof, it was only about 68 signal and the other channels all took severe hits. 64/67 were below watchable. So he turned it slowly until he hit a happy medium. I didn't watch him as i was looking at the meter, but I know, that for some reason, tiny movements here make a huge difference. I'm still kicking myself for not realizing when he turned the thing, at SOME point he should have gotten 80s for channels that i did get it for inside.

Maybe i AM aiming down a tunnel and dont know it

You've probably seen me post it before but here are the heights/powers (strengths were from IN the attic)

uhf station signal power height
26 (cbs3) 90-92 770/375
31 (pax61) 90-91
32 (upn 57) 90 250/400
34 (wbye35) 80-85 358/377
42 (fox 29) 25-45 305/161
54 (wb 17) 60ish 500/354
64 (abc 6) 85+ 500/390
67 (nbc10) 85++ 560/377

fox sucks in both categories. No word on their new tower either.

[TyroneShoes]

You will notice that the FOX station is lower in power than most, and lower in height than any. That would indicate that higher (for your antenna) might be better, and more amplification could also help. Are they all from the same general direction? A 4228 would be slightly better for that particular list of channels, if you could make that swap without having to buy a second antenna. Or you could gamble 50 bucks on a 4228 and try to sell the DB8 to someone else who it suits a little better.

[newsposter]

yes all the same direction except fox is 2 degrees off. I'm inclined to stick with the DB8 only because i did get mid-high 80s inside and the worse I can do in the end is put it back inside and give up fox until later this year with DTV dvr. I've looked around and there are no 4228s around here locally so i'd have to order. I'd sooner ask the guy to put up his fav antenna to see what it does since I have to pay someone to do the roof thing anyway.

I've really been analyzing this situation after trying to get over being upset and moving it the few feet away from the chimney, right above where i had it inside, simply must bring the signal up. There's no way i can have that messed up a topography. But I have no idea how long it's gonna take to put a tripod on at 60 bucks an hour.

If 2 degrees isn't an issue per se, even with the crappy power/height, then i'm hoping him spending the time with the db8 walking along the roof can resolve this.

[A J Ricaud]

If 2 degrees isn't an issue per se, even with the crappy power/height, then i'm hoping him spending the time with the db8 walking along the roof can resolve this.

I think you have a good shot at that working out for you.

[TyroneShoes]

...There's no way i can have that messed up a topography...You could make a general assessment. The more hills and valleys, trees and watertowers, tall buildings, etc., the more severe the nodes will be. If you are looking over a corn field in Kansas, for instance, the nodes would be so weak (the difference between constructive interference and destructive interference) that you could place the antenna almost anywhere, and in the middle of Manhattan, 6 feet could make or break you.

[newsposter]

well i may as well live in the big city lol

checked the signal just now...amazing...so much better now...2 days of fierce winds did something. But i'm still not sure I'd want it guyed where it is. Can you guy on a chimney that extends out from the house (enough angle)? It seems like you'd only get 2 wires on and the way it is, you'd only get a 'front to back' guy. Is that sufficent ? I have no clue about this stuff. But it's obvious since it has moved since friday, i need pretty much a 100% firm mount with the thing.

earliest they can get back here is next week so i have a week to think about it. No matter what I think I have to at least get him to carry it along the peak to ensure I have best signal.

todays signals at 2pm

ch power
26 91
32 91
42 71 (best EVER)
54 71 (best ever)
64 80-84
67 74-78 but looks pretty unstable

oh and should he have added any sort of silicone etc? db8 has 2 connectors shielded that go into one. The 2 on the antenna have a boot but the 'joiner' doesn't. He didn't put anything on. does it matter?

[A J Ricaud]

I'm glad to hear that things are looking better. As for guying, you need at least 3 points of attachment. And for the chimney, I don't think it's a good idea to attach directly to a chimney by using anchors or the like. You can, however, loop around the chimney as an attachment point.

It would be a good idea to seal the coax downlead at the combiner ("joiner"). Maybe ask him to put on a boot and a new connector on the coax because he will have to remove the connector to put on a boot.

[newsposter]

he did loop around with that kind of chimney mount

and while i'm guessing you could get 3 points...they wouldn't be the most advantageous 3 points in the current location (unless you did it on the side of the house somehow :))

[TyroneShoes]

3 (guy points) is definitely recommended, but 2 is better than none.

I would say he has some 'splainin' to do, regarding why your install didn't hold up in wind and weather. Good connectorization technique can preclude the need for boots and silicone, but adding those certainly can't hurt, and is good insurance against sloppy technique. Also, boots are not as good as heat-shrink, as they sometimes trap water rather than prevent its ingress (no new connector needed, either). Most installers worth their salt use heat-shrink boots that have gorilla-snot (yes, that is the accepted colloquial term) on the inside surface. They never leak. The installers that don't sometimes belong to a group who look forward to sticking you with another service call, 2-3 years down the road. Do I sound skeptical? Probably, but also probably for good reason.

[newsposter]

well i wont alienate him until i see how he does this 2nd attempt. If the db8 truly goes right above where it went in the attic, there will be enough space around it to guy 4 places lol. I dont care how it looks, i want accuracy and dependability. I'll do the lowest tripod it takes to get a good signal. I dont need the thing 10ft off the roof unless it's essential to get the signal.

heat shrink boots..never heard of them..intersting. do that even in place of the 2 db8 boots already on there? And are they easy to get off if need be? (my luck is they will be)

[newsposter]

I know i'll drive myself nuts with readings...but 8am today


ch power 1pm reading
26 92 92
32 92 92
42 71-76 71
54 65-70 65
64 89-92 71
67 89-92 68

So I dont know if the antenna is getting better or it's just a time of day thing lol.

I hate this since it confuses my options. I'm hoping for heavy rain/winds tomorrow to test more. :)

[TyroneShoes]

...heat shrink boots..never heard of them..intersting. do that even in place of the 2 db8 boots already on there? And are they easy to get off if need be? (my luck is they will be)
Slice and peel, replace. You can get heat shrink tubing at any electronics store, but I think the only place I've seen the ones with the inner goop is commercial stuff for CATV...not sure where to get that anymore. Regular half-inch heat shrink works fine.

[HomieG]

Another option that has worked very well for me is sealing connectors with "Coax Seal" which has generally been available at my local Radio Shack store. It's a soft and moldable type of "tape" wraps around connectors. Been using it for 6 or 7 years now on my DirecTV connections at the dish and grounding block and the original stuff is still sealing those connectors very well.

[newsposter]

Tiny update on my DB8 antenna saga for anyone following along. And he did seal the coax this time after I asked him to. After the guy trying every foot or so on the length of my roof, and even a higher roof, I settled on the original spot over the place in the attic where i got great numbers. I'm definitely shooting between a house and an unseen object in the distance. The installer was pretty flabbergasted how just a foot made a huge difference.

So now that I was 6ft away from the chimney, using a tripod and 5 ft pole instead of a 10ft on the chimney, I'm pretty confident the high winds wont move this mount again. CH 64/67 are in the 80s. Ch42 is a solid 71. Wb 54 is a somewhat solid 68. Of course cbs/upn are 90 since they are in the lower UHF.

In my case, higher wasn't always better. A foot horizontally made the difference between 10-15 on the signal meter. I spent 400 in labor etc getting it this far so hope they kill ch 54wb and move the programs down to 32upn. Then I'd be set. Or if they even put CW on directv I'd be ok if the signal was as good as OTA (not likely though)

[HomieG]

Excellent news, newsposter!

I've been battling a problem with my ChannelMaster 4228 install. It's mounted in my attic. When I first got the antenna, mounted and aimed it, all was well. All of a sudden I lost DTV signals on Channel 10 and Channel 48 (Atlanta analogs 11 and 34, respectively). All the other DTV signals were just fine. I was just about out of ideas, and stumbled onto the fix. Turns out the screen of the 4228 are two halves. The bonding between them is very important. When I got them bonded tightly again, the Channel 10 and 48 DTV signals came back. The bonding between those two screen halves is not very good, and I could repeat the signal loss, then full signal, over and over. I am going to solder or braze those two screen halves together. After I was done with the troubleshooting, I decided to google for this problem (and yes, I had googled before but not with the right keywords). Interesting article here describing this exact situation, at least for the VHF part:
http://www.hdtvprimer.com/ANTENNAS/cm4228.html

[newsposter]

I never used a 4228 but the guy did try to install his version of it. winegard I think. It did a bit worse than the db8 so my 50 extra bucks was well worth it in my case for the db8. It's a shame the bonding wasn't so good for you BUT at least it's a definable problem with a solution. Would a paper clip work temporarily? :)

I'm still gonna be watching these signals because i'm paranoid. had very strong winds last night and it still shows pretty solid. But I'm glad I spent the time getting it aimed just perfectly and getting mid 80s on the higher uhfs. In winds it went to 71 or so and i'm guessing the tree 200ft away does present multipath problems. I just hope they leaves aren't a problem in spring. But as long as the signal is above 60, i've found HDtivo can record it just fine.

you mentioned 2 analogs. Do you mean you are getting them on your 4228 or that you are getting the digital versions of them on the antenna? What I have to worry about is in 2009, ch 64 is going back to 6, and I think 64 will go back to 10 but i'm not sure because they aren't in the FCC pdf i found as making a choice yet. So I'm not sure the DB8 will get in vhf so well but hey, that's 3 years away!

[A J Ricaud]

What I have to worry about is in 2009, ch 64 is going back to 6, and I think 64 will go back to 10 but i'm not sure because they aren't in the FCC pdf i found as making a choice yet.

Can you post a link to the FCC pdf, please?

[HomieG]

you mentioned 2 analogs. Do you mean you are getting them on your 4228 or that you are getting the digital versions of them on the antenna? What I have to worry about is in 2009, ch 64 is going back to 6, and I think 64 will go back to 10 but i'm not sure because they aren't in the FCC pdf i found as making a choice yet. So I'm not sure the DB8 will get in vhf so well but hey, that's 3 years away!

Let me clarify. The two channels I was having trouble with in Atlanta are:

NBC - Channel 11 (NTSC/Analog) = Channel 10 (ATSC/DTV)
Univision - Channel 34 (NTSC/Analog) = Channel 48 (ATSC/DTV).

I get the Channel 11 (Analog) and Channel 10 (DTV) signal just fine now on the 4228, since the fix on the reflector screen. Before that fix, I got very low DTV signal strengths on Channels 10 and 48. Channel 11 and 34 were OK (analog) before the fix, although after the fix their ghosting is gone too.

As far as signal strengths after the fix:

Channel 10 - 89%
Channel 48 - 85%
They were both unobtainable prior to bonding that reflector screen.

On the 2009 changeover, I've seen that list. A good friend of mine who works in the TV industry told me yesterday that part of the 2009 FCC mandate is that low-band VHF goes away (to be auctioned off). Perhaps I misunderstood him, or perhaps it is just certain low-band VHF channels that go away, I don't know. Anyone else know about this?

[newsposter]

Can you post a link to the FCC pdf, please?

http://hraunfoss.fcc.gov/edocs_public/attachmatch/DA-05-2649A2.pdf

and just as an aside, here is the page that shows antenna heights and powers of your local tv stations (the bookmark is for my philly locals but you can adjust the search of course)

http://www.fcc.gov/fcc-bin/tvq?state=PA&call=&arn=&city=philadelphia&chan=&cha2=69&serv=&type=0&facid=&list=1&dist=&dlat2=&mlat2=&slat2=&dlon2=&mlon2=&slon2=&size=9

[newsposter]

Let me clarify. The two channels I was having trouble with in Atlanta are:

NBC - Channel 11 (NTSC/Analog) = Channel 10 (ATSC/DTV)
Univision - Channel 34 (NTSC/Analog) = Channel 48 (ATSC/DTV).

They were both unobtainable prior to bonding that reflector screen.

On the 2009 changeover, I've seen that list. A good friend of mine who works in the TV industry told me yesterday that part of the 2009 FCC mandate is that low-band VHF goes away (to be auctioned off). Perhaps I misunderstood him, or perhaps it is just certain low-band VHF channels that go away, I don't know. Anyone else know about this?

Now it's clearer for me. It's cool the 4228 got vhf in for you. Maybe I have a chance with my db8 since it was better than the installers knock off 4228:)

wouldn't low band vhf include channel 6? The philly 6 has elected to go back to 6 from 64 and even though the pdf file is by no means final, i'd find it hard to believe they would 'waste a pick' on something like picking a station they know wouldn't exist in 3 years. I'm just glad they are hacking off above ch 51 as it will be easier for the public to receive the lower stations, espeically those cheapos that wont boost their power or height.

[A J Ricaud]

http://hraunfoss.fcc.gov/edocs_public/attachmatch/DA-05-2649A2.pdf

and just as an aside, here is the page that shows antenna heights and powers of your local tv stations (the bookmark is for my philly locals but you can adjust the search of course)

http://www.fcc.gov/fcc-bin/tvq?state=PA&call=&arn=&city=philadelphia&chan=&cha2=69&serv=&type=0&facid=&list=1&dist=&dlat2=&mlat2=&slat2=&dlon2=&mlon2=&slon2=&size=9

Thanks for the follow-up, newsposter.

[TyroneShoes]

...wouldn't low band vhf include channel 6? The philly 6 has elected to go back to 6 from 64 and even though the pdf file is by no means final, i'd find it hard to believe they would 'waste a pick' on something like picking a station they know wouldn't exist in 3 years...
It certainly does. Low V is 2-6. 6 is 83.25 MHz, and channel 7 is about twice that high, which is why a UHF antenna like the 4228 can get channel 7-13 but not channel 6 or lower.

They have not wasted their pick, the reasoning is probably because 6 can be operated at with equivalent coverage (or possibly even better coverage) at a much lower power consumption than they can get at 64. Though low-V is susceptible to impulse noise interference, that is primarily 2-4. 6 is probably pretty immune, and there might even be some eventual 5's at DT. It takes money to swap to a different frequency, but they would be required to swap to something below 52 anyway, so 6 probably makes even more sense for them, especially if they can't get a low U like 15-20, or a high-V.

If they choose 6, that is what they get grandfathered to. 6 will not go away for them. The only channels that "go away" are the channels that are not picked, and those above 51.

The 4228 is really a UHF antenna, and the screen-bonding modification is just a happy accident of that particular design that makes it viable for high-V channels. CM doesn't claim anything below 14, which is probably why they don't really bond the screens. But as many have discovered, it is an easy and harmless modification that allows high-V without compromising U performance.

[Tom J]

It takes money to swap to a different frequency,
And if the FCC would ever require (unlikely) TV to vacate low band VHF, it would be to make room for potential new commercial services. In that event, those new services would have to pay the costs of moving that station to a new frequency.

[Tom J]

Tyrone or Greywolf, how about taking a stab at this...

I'm familiar with the "edge effect" at microwave frequencies (2GHz), where, if you are unable to get a direct line-of-sight signal because a building is in the way, you can point the antenna at the corner or roof line of that building and many times you can get a great signal. (The theory is that the wave refracts(?) off that sharp edge.) However, I don't know if, or how low in UHF frequencies that this still applies. Thoughts?

Tom J

[newsposter]

nbc 10 apparently has chosen uhf 34...so that will help me out in keeping the db8 up and running. Also should be very strong signal versus old channel 67 :)

http://www.fcc.gov/fcc-bin/tvq?list=0&facid=63153