Do antennas "wear out"?

Bigbear · 13-Jun-2014, 11:01 AM

http://www.tvfool.com/?option=com_wrapper&Itemid=90
Here is my map.
My set up is an old uhf/vhf antenna mounted about 25' up. I don't know the model as it came with the house ~25 yrs. It has 10 main elements.
I use 75 ohm cable with a pre amp on the pole. Cable down to a grounding fitting then into the house to the power injector. From there to a channel master distribution amp ( 4 outputs) then throught the house.

My issue: Up unti recently I was using a wineguard AP-8700 pre amp and with that I could point my antenna to the NNW and get the 4 stations from Montreal ( Ch 12,13,6, and 7 which is not on the map). Leaving the antenna pointed this way I could get all my local channels from the "back" of the antenna.
One morning I could get only a few stations and determined that the pre amp had died.
Replaced it with an Antenna Craft 30Db ( AP-8700 no longer available)
Now I can only get Ch 6 out of Montreal and can not get any of my locals from the "back" of the antenna. I have to point it to the east to get them.
Any idea as to what I'm dealing with?

Thanks
Bear

Jake V · 13-Jun-2014, 1:00 PM

Bigbear,

Your TV Fool map is blank. Go to that link and enter your address, then click "Map This". Then copy that URL and paste it here.

To answer your question, look up at it from the ground with binoculars or a camera with a zoom. If it looks normal, and there are no elements missing, and it's still pointed in the right direction, it might be OK.

My first suspicion would be the connections, and then your pre-amp and splitter. I'd inspect the cable and connections (every inch) from the antenna to each television, and even run a new cable direct from the antenna through a window or door to one television as a test. [Your description is not clear whether you added the cable 25 years ago or recently.]

What antenna are you using (if you can't tell can you post a picture)?

When the antenna worked correctly, what channels did you get?

When did the channels stop coming in?

What channels do you get now?

When you adjusted the direction did you use a magnetic compass?

It sounds like there are several things you can check before you begin a discussion about a replacement antenna.

Jake

ADTech · 13-Jun-2014, 1:26 PM

Quote:

Do antennas "wear out"?

If outdoors, antenna components and accessories do tend to degrade over time, primarily due to the effects of water infiltration into baluns, coax cable, and connectors, corrosion between adjacent metal components and connections, and the potential for electronics to get "zapped"by static discharges (ie, lightning, etc.).

If you replaced a medium gain preamp with a high gain amp and you're feeding that into a distribution amp, the probability of overloading an amp or tuner is very high.

Let's see the corrected link to your TVFool plot so we can get a better idea of what's going on.

Bigbear · 13-Jun-2014, 1:36 PM

Sorry and thanks for the tip as to how to post map.

http://www.tvfool.com/?option=com_wrapper&Itemid=90
My cabling is not 25 years old as I changed from 300 ohm about 10 years ago.
I have weather boots on all my exterior connections and had changed nothing prior to the incident that caused the channel losses.

Channels I recieved prior to the recent issue:
2.3.5.6.7.10.12.22.33.44.57.
Now I can get 3,5,6 ( but I have to rotate the antenna) 22,33, and44.

As for the antenna I don't know what model it is, but it looks like an Antenna Craft C290 with only 10 "rear " elements and without the smaller elements between the larger ones at the rear.

I chatted with someone from Solid SIgnal who mentioned that the Canadian stations could have changed their footprint. Don't have a clue as to what that is.

Jake V · 13-Jun-2014, 1:41 PM

I just realized you used the map feature. On that screen, make sure the pointer is over your house (you can zoom and switch to "Satellite") to get it exact, then enter the proper height of your antenna, and then click on "Make Radar Plot". Then use that URL.

tomfoolery · 13-Jun-2014, 2:06 PM

Quote:

Originally Posted by Bigbear

Sorry and thanks for the tip as to how to post map.

http://www.tvfool.com/?option=com_wrapper&Itemid=90

You're still stopping short of the finish line. After mapping and adjusting the icon location using the satellite view and adjusting the height to 25 ft, hit the Make Radar Plot button at the top-right corner of the map. A new web page with the so-call 'radar plot' will be generated and be unique to whatever you mapped. Copy this url to your response, not the map page.

Look at the links in other folks' posts to see what it looks like if you're not sure.

Bigbear · 13-Jun-2014, 2:35 PM

Sorry again
try #3
http://www.tvfool.com/?option=com_wr...e1c6315dcb598f

Bigbear · 13-Jun-2014, 2:48 PM

I did change the balun with my newest pre amp.
Maybe I wasn't clear earlier that everything was working fine for at least 2 years with the set up I first described.
Then one morning everything had changed. It rained like the dickens overnight and the reception was bad. I started trouble shooting and when I took the power injector out of the loop reception for the locals was restored, but I could not get the Canadian stations ( 2,6,7,10, and 12).

tomfoolery · 13-Jun-2014, 2:55 PM

My first inclination is that there is water in the coax connection(s). Those boots aren't as watertight as you might think, and may even by holding water inside once it gets in. Getting some dirty water in there may have also shorted the power to the amp just enough to stop it from working, and any degradation of the signal itself is, of course, a bad thing.

The amp without power to it is likely to block most of the signal, too, which would explain your still getting strong local signals but losing the distant stations.

I'd start with cutting off the terminations and reterminating with good quality compression types. If that works, then seal with Coax-Seal and maybe cover with tape to keep the sun off.

Bigbear · 14-Jun-2014, 1:22 PM

Not to dismiss any of the suggestions but I'm still puzzled re the water getting in to the outside connections. I also have a DTV 18" dish with dual LNB that each of the cables have similar connections with out boots and I have no issues with their signals.

Can I " dry " out connections with WD 40?

Stereocraig · 14-Jun-2014, 2:55 PM

Quote:

Originally Posted by Bigbear

Not to dismiss any of the suggestions but I'm still puzzled re the water getting in to the outside connections. I also have a DTV 18" dish with dual LNB that each of the cables have similar connections with out boots and I have no issues with their signals.

Can I " dry " out connections with WD 40?

Water can and will "Wick" into the coax itself.
The only way a WD product would work, would be if you could chase the water out the other end.

Heat, UV and extreme cold, can do strange things.

Bigbear · 14-Jun-2014, 3:43 PM

I am humbled , just got back from re making my connections at the grounding block. They were quite corroded and black inside the threaded area.
Now I've got all my channels back from before the wicked rainstorm.

There is some white residue on the grounding block threads but it doesn't seem to effect the signal. Easier to swap out than clean?
Is there anything else I can seal up the connections with until I can get Coax-seal? BTW these connections never "see" direct sunlight, and I have " drip coils" in the connections. Guess drip coils aren't the end all!

Thanks folks I'll never doubt you again!

Are there weather tight crimp on connections like what my satellite tv tech used? They seem to hold up after 10+ years mounted at the same place as my off air connections are.

ADTech · 14-Jun-2014, 3:51 PM

Quote:

Are there weather tight crimp on connections like what my satellite tv tech used?

Sure. They're called 'compression' coaxial fittings. You can pick them (and the tools) at Lowes or Home Depot, for example.

Stereocraig · 14-Jun-2014, 4:20 PM

WD and a wire brush will clean up that white Aluminum oxidation quite well.
If it's not cleaned, it will just continue "Crawl" into the other parts.

Any type of grease should be fine temporarily, just not any type of Anti-Seize because of it's Nickel content.

Remember though, all oily parts should be cleaned w/ Lacquer thinner, or Acetone, or else the Coax Seal may not stick.

Bigbear · 15-Jun-2014, 1:14 PM

For those that wanted a picture of my antenna.

Bigbear · 15-Jun-2014, 1:42 PM

Question about compression coaxial fittings.

This is my crimper. Will it work for the above mentioned fittings?

ADTech · 15-Jun-2014, 5:50 PM

Quote:

Originally Posted by Bigbear

Question about compression coaxial fittings.

This is my crimper. Will it work for the above mentioned fittings?

Nope.

Go to Home Depot's website and search for "coaxial cable compression tool". Note that two/three layer shielded coax uses different connectors than does quad shield, so match up to what your coax cable on hand is.