I have been having problems with receiving 11.1 ABC in Raleigh NC.

This is an attic mounted 4228 fix mounted antenna connected to a A/B switch which is than boosted with a RCA booster. I think the booster is 24db but don't hold me to it.

By the way, I can not receive the signal 2 floors down without using the booster.

What has happened is that my OTA Digital reception on ABC 11.1 has gone from a solid 85 percent to around 75 % signal strength.

The big problem is that it will drop to arond 45 % and I will lose the signal for over a minute after about ten minutes of viewing. Then it will go back up to a steady 73 to 75 % signal strength for a period of time before it again drops to 45.

I replaced the a/b switch but problem remains. I even took the a/b switch out of the circuit and problem remains.

I hoped it was that 11.1 was not xmitting at full power but not sure if this is the case or not.

All other stations appear to be working the same as always.

I thought maybe it was a ghost problem but when I switch to the analog tuner and view the same channel I see almost zero ghosting. If I use the a/b switch to switch to my other antenna in the attic which is pointed in the other direction I get significant ghosting as I would expect.

I believe the analog and digital xmitters are mounted on the same tower.

I can't figure out what could be causing this problem and hope one of you antenna experts have an idea.

Can a amplifier fail causing this kind of problem ??

-Thanks in advance'

Don B

Sounds like you're right on the edge of an acceptable signal. With analog the result was some snow, with digital it's pixellation, loss of signal, and sound dropping out. That's the problem with digital... it's digital... you've either got it, or you don't!


You might benefit from a preamp with more gain, and possibly a lower noise figure. I'd look up your amp, and see if you can get something better at a reasonable price. I'd try to buy from somewhere local, if it doesn't work, take it back.

It also sounds like you might have the amp after an A/B switch. Note that the loss through the switch could easily be 3dB, so try moving the location of the amp to before the A/B switch.


Unfortunately, the picture for HD is transmitted over two different channels, and presented to the user as one. Because you aren't seeing issues in the one band is not a guarantee that it isn't occuring in the other.

My guess is that this has gotten worse due to buildings, trees, sign's, etc causing multipath. Another possibility is that weather conditions are causing issues. For example, a wet roof will give slightly worse performance for attic mounted antenna's than a dry roof.


Doesn't sound like it's the amplifier failing from your description. If you are getting channels above and below this one, the amp failing is unlikely. It sounds to me like you were on the edge of an acceptable signal before, and something outside of your control has given you a little push.

I would try a better amp. If that doesn't work, you can always try temporarily putting the antenna outside. If that fixes the problem, chances are you can mount it outside even if you have Deed Restrictions or Covenannts that restrict. This has been shown to not be within state powers, and the FCC allows you to mount the antenna outside in almost all instances.

See the link:
[Link: fcc.gov]

BCF1963,

As per your suggestions I moved the RCA booster before the A/B switch and on a 3 ft length of Coax from the 4228.

Did not have time to test it.

Hope to test it tonight.

Interesting what you stated about the Analog vs Digital channel reception.

Thanks,

Don B

There are some digital channels somewhere in the US that are in the VHF band, but most are on UHF frequencies. That means that comparing 11 and 11.1 will be comparing 11 and anything from UHF 14 to 69! You get the impression that you are just switching from one type of signal transmission to another, but, no.

Somebody figured out that the public would be a lot more accepting of adding .1 or -1 to existing channel numbers than of learning a whole new set of channel numbers. It was already complicated enough! The only people who have to cope with the exact channel assignments are those who are techish enough to try to look at signal strengths on a meter.*

You can get a list of all the stations in your area that the CEA thinks you can receive by going to www.antennaweb.org and pretending you want to specify an antenna.

Along with the other information, they list the actual channel numbers of the digital stations. They will tell you what direction to point it, list stations in order of receivability, and even give you a street-level map. I use printouts of these maps up on the roof to point the antenna; just compare the lines on the map with the street below you, and no compass is necessary.

*By the way, one reason that the "signal strength" can vary so much is that it is signal QUALITY, not strength, shown by the receiver. This is a somewhat nebulous characteristic that includes strength, but has to do with a lot more than that. Now, if we could just find somebody who could actually describe what makes up that number! I have been asking about this since the first RCA receivers came out, and only gotten vague answers.

After moving the booster closer to the 4228 and before the remote A/B switch I found that last night and this morning I am receiving 11.1 steadily albeit at a lower "QUALITY" level.

Ernie, I was not aware that antennaweb.org gave street level info this is good to know as the only compass I own is the digital one which is part of the Jeep and kind of hard to carry up to the attic.

Now the down side to all this is that PBS which comes in on 4.1 is now at a lower signal level coming from my Square Shooter 2000 which feeds thru the other side of the remote a/b switch. But at least last night it didn't break up all evening watching the HD show about Mt Kilimingaro - excuse the spelling.

If 4.1 starts giving me problems I will try adding a booster before the a/b switch on the Square Shooter side.

Or I will look into a rotator but not sure what the better half would think of the sound of the rotator motor eminating from the attic whilst she is upstairs and I am still downstairs channel surfing.

-Don B