Well, my CM4228 arrived, but...

[jammy]

I posted earlier regarding not being able to pick up most digital OTA signals in the DFW area of Texas. I have a DirecTV HR10-250 satellite receiver.

Previously, the only major digital station I was able to get with my 'old' antenna was 8-1 (ABC).

When I tested signal strength a couple of days ago, I found that I was now able to bring in all stations except 11-1 (CBS and 13-1 (PBS). So, miraculously, I now had 4-1 (Fox) and 5-1 (NBC) as well as 8-1.

I ordered a CM4228 from Warren Electronics; it arrived today.

I hooked it up in the attic and tested it.

I found I could get all digital stations except 11-1 (CBS) and 13-1 (PBS) - just the same as I was finally able to get from the old antenna.

I guess my questions are:

1 - I suppose it is no use hooking up any kind of amplifier, as it can only amplify a signal that is already there. I get no signal strength on the channels I still want to receive. Is that right?

2 - All the digital channels are at 22-23 miles away. Is there a big difference in the strength of signal that each station broadcasts at?

3 - How critical is the direction the antenna is pointed in? Funnily enough, the channels I get are at either at 156 degrees or 157 degrees. The two I can't get are both at 154 degrees.

4 - Will it make much of a difference if I install the antenna outdoors? I am reluctant to do this, but if it will get me those other digital channels....

I look forward to hearing from you.

Thanks.

 

[charper1]

I guess my questions are:

1 - I suppose it is no use hooking up any kind of amplifier, as it can only amplify a signal that is already there. I get no signal strength on the channels I still want to receive. Is that right?

I am no expert with amps.

2 - All the digital channels are at 22-23 miles away. Is there a big difference in the strength of signal that each station broadcasts at?

Not always, but yes, not all stations broadcast at the same, high power.

3 - How critical is the direction the antenna is pointed in? Funnily enough, the channels I get are at either at 156 degrees or 157 degrees. The two I can't get are both at 154 degrees.

Yes, sometime you might find it necessary to "peak", not just aim at a heading and walk away.

4 - Will it make much of a difference if I install the antenna outdoors? I am reluctant to do this, but if it will get me those other digital channels....

ABSOLUTELY YES, you should be mounting outdoors. There is federal law protecting your rights to do so; so do not worry about any city ordinance that states you can't.


I look forward to hearing from you.

Thanks.[/QUOTE]

 

[texasbrit]

OK, at 22 miles you should not be having this problem.

11.1 has been having some problems recently, it is possible it may be off the air for repair, otherwise it is one of the easiest channels to get.
13.1 can be a problem, it seems to be very susceptible to multipath - try peaking your signal just on 13.1 by rotating the antenna and see what you get. Connect the antenna to a regular NTSC tuner, what's the analog picture look like on channel 13?

If you get zero on channels 11.1 and 13.1 this is likely because of poor signal QUALITY not signal strength. Your meter gives you a quality indication so severe multipath will give you a quality of zero even if there's plenty of signal. An amplifier will not help with this so you need to find out what's going on. I had trouble getting a decent quality signal from 13.1 and eventually found the best position was about 15 degrees away from the direction of the antenna farm at Cedar Hill.

You will get a better signal mounting outdoors but you need to try all the "tricks" before you do that. If you have multipath due to external factors it will still be there when you are outdoors.

 

[Rick0725]

Peak your antenna on your weakest channel between 154 and 157 degrees. We are not talking large movements. Step away, wait and take a signal reading. Touching the antenna and close proximity of your body to the antenna will affect signal and your results. Be patient.

Look at a picture (analog). take a portable tv and the hd tuner with you up in the attic if you have to and peak without the "honey how does it look method". Notice if there is any ghosting or snow in the analog picture. The signal strength meters in HD turners actually do not measure signal strength but bit errors or some other kind of nebulous measurement most tech types can not describe with any intelligence.

Also experiment with heigth off the floor.

It is always best to install the CM4288 outside for best reception.

The best preamp for 20 or so miles is the winegard HDP-269 and will not overload your setup. Installing that preamp will not hurt things one bit.

 

[charper1]

If you are using the honey how does it look method Rick mentions above; I have found that a set of $35 - $50 Wal-Mart or Target two-way radios are a HUGE help; and great for the kids fun or other safety and outdoor events.

http://www.walmart.com/search/brows...t=3944&ic=8_0&ref=125875.243660&search_sort=4

I have a set of the T5530's and we low them.

 

[snathanb]

Jammy,

With that distance and antenna type I really don't think you should be having problems.... you might have a bad cable.

One other question.... what type of roof do you have?

 

[jammy]

snathanb

Yes, I didn't think to check if the cable was OK.

By the way, what do you mean by what kind of roof do I have?

Thanks

Jammy

 

[bhelms]

Well, a steel roof might cause some reception problems, for instance. Other materials like metal backing on insulation in the attic will have some affect as well. Even ductwork in your attic might block some signals or cause undesirable reflections...

If you're using the 2-way radios for fine-tuning (recommended), remember that the signals from those radio can also affect your TV reception. You might need to move away from the antenna or turn-off your radio to prevent that...

 

[texasbrit]

Use two cellphones for the Tv to antenna setting-up voice link - if they are from the same carrier the calls are probably free....

 

[jammy]

I may have said this here before, but I really am grateful to all who have responded here.

By the way, my roof is regular shingles and there is no insulation in the way.

I will let you know how my investigations of proper orientation for the antenna go.

That last sentence doesn't sound quite right - there must be a split infinitive in there or something!

Bu the way, texasbrit, I take it that you are from the UK originally. So am I - Belfast.

THANKS TO YOU ALL!!!

 

[charper1]

I do have to ask; there is NO insulation in your roof rafters between the antenna and the under side of the roof? That can't be good!?!

 

[Rick0725]

Voice link...walkie talkies...That would drive me absolutely crazy!

Honey...how does it look...better...better now...how bout now.

oh man

 

[charper1]

And it does, but some of us don't have a mini-portable to use; that IS the best idea.

 

[Rick0725]

mini portable (old school just used to check for ghosts, snow, and interference...tough to use in the daylight (tough to see picture)... and in 2009 is going to be a lost art.

so now use an actual fancy signal level/strength meter which works with analog and digital while looking at 6 signals at once.

The manufacturers need to come up with an inexpensive signal strength meter for digital antenna tweaking that is as easy to use as a radio shack sound pressure meter. if the signal goes up the meter goes up...if the signal goes down the meter goes down. Hook the meter direct to the antenna tweak for best signal and call it a day.

A meter that actually measures signal strength not some nebulous strength even the tech types can not explain or understand fully.

 

[charper1]

That would be nice to have

 

[HatGuy]

I am in Fort Worth and have the same antenna about 30 feet off
the ground. I had to move it to different locations around the house.
3rd place was the charm. Still not perfect added a winegaurd amp
(sorry cant remember the #) Rick will know the one. It got better & then
I added guy wires so it would not wave around in the breeze. Without
knowing till I got down I had pulled one of the guy wires to tight and
caused the mast to bow slighty making the antenna tilt up just ever
so slightly. Everything works great now.
I highly recomend moving it out side. A telescoping mast from the ground
makes things easer and you can experiment with the hight. Higher is not
always better.
Rick thanks for all your advice.

Good Luck

ps 25 miles from the towers

 

[Rick0725]

on your installation, is there anyway to use sections of metal conduit in place of guy wires.

I have gone away from guy wires since they can be troublesome especially when the turnbuckles come loose, etc.

I usually use 2 or 3 pieces of conduit (depending on the type of install) in 8 ft or longer lengths depending on availability. I hammer the ends to fit. attach one side to the mast using u bolts and the other side is lag bolted to the roof supports.

This set up will not move during wind gusts and offers a spot to hold onto while you are working on the antenna setup while on the roof.

you can see that setup on my avitar for my install at home.

 

[jammy]

Hi there - Jammy here - you knowme, I'm the guy who started this thread and apparently have an insulation problem in my attic!!!

Seriously though (and without trying to get off topic for too long), my actual roof does not have insulation.

The 'floor' of the attic has plenty of insulation and it seems to be doing its job.

The last time we had snow here (I can't remember exactly when) I compared how long my roof had snow on it compared to neighbors' roofs.

My snow cover was one of the last to go. They tell me this is a sign of good insulation - i.e. the insulation on the floor of the attic prevents the heat in the rest of the house from getting to the roof, so the snow remains there longer.

And this is doubly good, because the snow itself acts as an additional insulator!!!

On the subject of getting my antenna to pick up all the digital channels in the DFW area, I will try to get this figured out this weekend. I haven't quite worked out the best way to do it - I want to be able to turn the antenna in small, equal amounts and see what I get on the TV.

WE SHALL SEE......

 

[jammy]

Adventures of an antenna mover...

Well, I'll give you my progress so far.

1 - Though it didn't quite work for me, here's a suggestion for determining if your antenna is picking up a channel that you are missing - and there is no-one else in the house to help you.

Tune your TV to the channel you want. You'll get a black screen and/or with my DirecTV, you'll get a 'searching for satellite' message.

In order to avoid having to run up and down stairs, simply turn up the volume on your TV (presuming you can hear your TV from the attic or on the attic stairs. If you hear the TV, you've pointed the antenna in the right direction; if not, continue to change the direction of the antenna until you hear the TV.

I think that may be a good suggestion.

2 - The above didn't work for me (I am really having difficulty pulling in my PBS and CBS signals).

So, using one of the cardboard wrappers from the packing of my CM4228 antenna, I put one end of the wrapper on the floor of the attic and the other end in contact with the antenna.

I then made marks on the attic floor and numbered them. I adjusted the position of the antenna by moving the wrapper to one of the numbers and then checked to see what signal strength I was getting on the TV.

I still have a few more positions to check, but the best I was able to get on those 2 channels was a strength of about 15-25. However, a couple of times the meter briefly peaked at 100. I was somewhat happy with the results, as before, I had been getting zero signal strength on both these channels.

I know this all sounds a bit crude and would not be a permanent solution, but at least I have a logical way of setting the antenna in one position for at least long enough to determine signal strength. I'm sure there are lots of ways of doing this, e.g. with string, but this was my way. If I thought there was money in this, I would patent it!

Now, a question:

Given that I can get some signal on both those channels, does that mean that a pre-amp would work for me? The minimum signal strength needed to get an actual picture seems to be about 40.

Thank you in advance for your comments.

 

[techpuppy]

First of all your insulation is fine. That's the usual way of insulating--otherwise you'd be paying to heat your attic.

Did you try another cable? If the existing cable is several years old it might be worth changing it. If nothing else run a new cable while you test. If that's not practical check the connectors on each end. Are they in good condition, clean, shiny? You can use a bit of steel wool or fine sandpaper to clean them if needed. If you have an ohm meter or continuity checker try this: disconnect the cable from both ends. Put a test lead from your meter on the outer conductor. Touch the other to the inner conductor. You should get no reading. That would mean the cable is not shorted. Then take a piece of aluminum foil and use it to connect the inner and outer conductors together at one end of the cable. One lead of your meter to the inner and one to the outer conductor at the other end of the cable should show near zero ohms or beep if you're using a continuity checker. If it doesn't then one of the conductors is broken or one of the connections is bad. (Now you can see why most people just run a new cable).

Sometimes adjusting the tilt of a UHF antenna can make a difference. I learned this from some other sites while trying to pick up distant stations. Once you find the best direction for reception try tilting the antenna up slightly and see if it affects your signal. It's worth a try.

An amplifier might help out at this stage since you have some signal to work with. Once you've got your antenna aimed as well as possible and know that your cable is fine there's not much else to do other than an amplifier unless you decide to put the antenna outside.

For what it's worth I managed to pick up all but one local channel using an outdoor antenna. Even an amplifier wouldn't pull in the missing station. As it turned out my yagi UHF antenna was looking through a pine tree in the direction of their transmitter. Moving my antenna mast a few feet solved the problem.