Odd thing has happened twice . . .
 

Hi. About a half hour ago (it is now 2:00 AM) all my channels went dead on both my TVs. I normally get about a dozen channels or so.

This same thing happened around a year ago, and I assumed something went haywire with the antenna/cable -- there's no way all those channels could suddenly stop transmitting at the same time. But the next day everything was working fine, and has ever since. And I've forgotten about it, til tonight when it happened again.

I did a search here before posting and found this thread about a preamp going dead.

I put a whole new system on the roof in 2009, including a new preamp and cable going to two TVs (I don't remember for sure the brand of the antenna and preamp, but I'm thinking Wineguard). One of the TVs was replaced two years ago, the second one was replaced a year ago.

Everything has worked flawlessly since it all went black the last time, then came back on by itself. Any idea how it "fixed" itself overnight, and has been fine for a year or more?

If it doesn't come back on by itself miraculously tomorrow, before I go fooling around on the roof, is there anything I should do first? What do I check besides obvious connections to see if they're tight?

I'm not young, and am not crazy any more about getting up on the roof, but do it when I have to.

Thanks in advance!

FWIW: Both TVs worked as normal this morning.

Anybody got any answers or suggestions as to why, or how, this happened? :confused:

You could check the voltage going up to the preamp.

What model is the power inserter that is down below?

Your previous thread has some background information that might help others to help you.
TV signal slowly degrading . . .
http://forum.tvfool.com/showthread.php?t=13158

At that time, your signal problem was caused by electrical interference.

It could be a solar flare. Where do you live?


https://www.highdefforum.com/local-h...s-big-one.html

Google

https://www.google.com/search?source....0.qu8N5pVBc3I

What is a "power inserter"? :confused:

Ha, I had totally forgotten about that. I can't believe it was 4 1/2 years ago. :( I couldn't even remember the name of this site the other night, but I Googled around and recognized it when it came up.

I checked both those links; none of it meant much to me. I live in upstate NY, south of Rochester 30 or so miles, as the crow flies. Could a solar flare have been the problem?

You said you had a preamp. A preamp needs power to operate, and a power inserter sends the power up to the preamp.

A preamp system comes in two parts: the preamp itself up by the antenna, and a power inserter down below. The power inserter makes it possible to send the DC power up to the preamp on the SAME coax that sends the signals down to the TV.

http://i.imgur.com/uVHwqcw.jpg

If something goes wrong with the power inserter, then it might not be able to send the power up to the preamp to make it amplify the signals.

It is possible to measure the voltage at the power inserter to see if the voltage is there without going up to the roof. Of course, that is only he first step in trouble shooting a preamp. The results of that test will determine what you need to do next.

Do you have a voltmeter, or do you have a buddy that can make electrical measurements?

http://dennysantennaservice.com/1136577.html

Solar flares can knock out radio and TV signals. They can also knock out the power grid. You must remember the widespread blackout in the Northeast that started in Canada.

https://www.nasa.gov/topics/earth/fe..._darkness.html

https://www.inverse.com/article/3413...kout-nyc-earth

There has been loss of signals this week.

https://www.google.com/search?q=sola...iw=911&bih=345

So, it is possible, but it is more likely a problem with your preamp.

Aha, yes. Mine is a Wineguard PS-1503.

I have a meter, and know basic electricity, but know nothing about how this system works. What/where should I check? Can this thing go haywire, correct itself overnight, be fine for a year or so, then go through the exact same cycle again?

If it's working fine, like it is now, should I expect a voltage reading to be off or would I have to wait til it goes out again?

Here is the Winegard troubleshooting video:
https://www.youtube.com/watch?v=ZNPb1XNBQSI

Check the voltage now while it is working. If it goes out again, see if the red LED is ON or OFF.

You have an intermittent problem. I think you know how difficult that is------you have to catch it when it is acting up.

At this point, you don't know what is causing the problem. It could be the antenna, the balun between the antenna and the preamp, the preamp, the coax between the preamp and the power inserter (injector), the power inserter, or the power transformer. It could even be the signals.

Your job is to isolate the problem to one part of the system by substitution of known good components, even if it means a completely separate test antenna and coax.

I can't be any more specific because I don't know what your antenna looks like and I don't know what kind of signals you have because you haven't given us a tvfool signal report for your location. You can do a report here:

http://www.tvfool.com/index.php?opti...pper&Itemid=29

That might be somewhere near Geneso, Leicester, or Mt Morris.

Here is a report for Mt Morris. The Rochester signals aren't very strong, but WPXJ ION from Pavilion is strong enough to use as a test signal with a simple test antenna, if that is your location.
http://www.tvfool.com/?option=com_wr...e6a4f831e85205

Okay, transformer measures 29 V. and the "Ant" connection on the power inverter measures 16 V., both okay according to the video.

Everything has been working fine since last weekend, so I guess all I can do now is wait until it doesn't. :(

Thanks for the help! :D

EDIT: Actually, I did that but it didn't "stick" for whatever reason. I will do it again.

Here is the link they said to post.

FWIW: Here is what I really have:

I live in a hole, with a hill between me and the transmitters. If these signals only go in a straight line (as I've read) then I am only getting them because they are bouncing off one of the other hills.

NBC, ABC, PBS always come in fine. CBS is normally fine, but if the antenna isn't aimed exactly it can be dicey, depending on the weather.

I only get FOX from around September/October until April/May. It is like this every year, and was the same even before 2009 when it was analog. I assume it has something to do with the atmospheric changes as the seasons change. It does not correspond with the leaves being on or off the trees.

In addition to an intermittent electronics failure ithe problem could also be caused by interference. Is there anything electronic that you added lately?

Not since this problem as outlined in my last thread from 4½ years ago. :(

Thanks for checking the voltage to the preamp. If you have a problem again, check to see if the LED on the power inserter is still ON. as it should be, or OFF.

Thanks for the tvfool signal report.
http://www.tvfool.com/?option=com_wr...e6a4c5db6f4ec6
That description exactly matches your signal report. NBC, ABC, and PBS are your strongest signals, and CBS is listed just a little weaker than PBS. Fox is a lot weaker than CBS.

CBS sends 992 kW out of 1000 kW ERP in your direction. If you click on the CBS callsign in your report, this is what you will see:
http://www.tvfool.com/?option=com_wr...dALLTV%26n%3d4

http://forum.tvfool.com/attachment.p...1&d=1505609634

Fox is much weaker because it has a very directional transmitting antenna that sends only 11 kW out of 320 kW ERP.
http://www.tvfool.com/?option=com_wr...dALLTV%26n%3d5

http://forum.tvfool.com/attachment.p...1&d=1505610948
What you assume is correct; the seasonal change does make a difference. In the warmer weather, the Fox signal is not able to bend down to your location by refraction because the density of the air changes in warm weather.

Forum member tripelo says it much better than I can:

Are there any trees in the signal path from Rochester?

Does the problem get worse when it rains?

Will do.

I hadn't seen those pages, interesting -- I assume my house is way over on the right behind that big hill, heh.

I had no idea what all those numbers meant.

Also interesting. When I hung around with my high school buddy in the mid-late '60s (he was a CB radio bug) he was always talking about "when the skip comes down" at night, and the signal would travel much farther. Sounds similar. And I know AM radio signals can travel tremendous distances at night, all related to what Tripelo is describing -- I'm assuming.

My house is surrounded by thousands of acres of mature hardwoods, and there are tens of thousands of trees between me and the transmitters, although I'm guessing the hill between us, which is probably 500' higher in elevation than my house is, and 3-ish miles to the north, is more of a factor.

Yes, rain tends to make an edgy signal go out. But, and I bet there's a scientific reason for this, when I was on analog the signal came in better when it was raining.

=======================================================

EDIT: I see you added that image after I started this post. Yes, it all makes sense. This is the first time I've ever seen any hard science for all this. Before, all I ever heard was opinions and guesses from people who didn't necessarily know any more about it than I did.

Thanks! Gotta love the internet!

Trees block TV signals.
http://www.hdtvprimer.com/antennas/siting.html
scroll down to Trees and UHF
Wet trees block TV signals even worse than dry trees.

With analog TV, the signals just got a little more snowy as they got weaker.

With digital TV, they suddenly drop out at a certain point as they get weaker. This point is called the "Digital Cliff."

http://forum.tvfool.com/attachment.p...7&d=1465958114

The sudden dropout is caused by the FEC (Forward Error Correction system). The FEC is designed to correct the digital signal errors to maintain a good quality picture. As the digital signal gets weaker, there are more and more digital errors. The FEC has a limit to how many errors it can correct. Once that limit is exceeded, the FEC gives up, and the signal drops out.

Yes, I found out the different ways the signals act in 2008 when some of the local channels started with digital. And I learned that antenna aiming is more important with digital.

Aside from that (and the problem of everything going dead for hours, twice in the past year) digital has been a huge plus for me. Instead of 3-4 channels I get 12-14.

Back again. :(

I haven't had any more incidents of everything going completely out, but I am having reception problems.

As previously noted in this thread, I do not get FOX in the summertime but it always starts coming in around the end of September and lasts until maybe early May. This fall it didn't come in. So I've been on the roof numerous times rotating the antenna slightly either way. I have trees and a phone pole for reference points.

As time went on it started coming in, probably because the weather got colder, not from me adjusting the antenna.

So here we are in late November and I'm still having problems, not only with FOX but with CBS (my two weakest channels). I can't tell you how many times I've been on the roof (twice just today) and I'm getting tired of it. When winter sets in and there is snow on the roof, I will not go up there (too old for that stuff).

There has to be something wrong because I've never had problems like this, this late in the fall, since I installed everything new in 2011.

So tonight I re-checked the pre-amp, per the Wineguard clip that rabbit posted above.

Power supply, 27.6 V - good
"ANT" connection on injector, 15.1 V - good

So the next step I guess is to check the coax that feeds the preamp on the roof. If that checks out good, what is my next step? I would assume the pre-amp itself is maybe weak, but is there a way of checking that? TIA. :D

EDITED TO ADD: The reception problems I am having now are just slight -- enough to be annoying like the audio cutting in and out, or occasional pixelation -- but sometimes more than I want to put up with so I have to switch to something other than CBS or FOX.

If you have a Winegard antenna, you likely have the CB-8269
cartridge housing. That is the black box where you attach your
cable to the antenna. Those parts tend to get wet, deteriorate
with time and weather. Before your weather turns really bad,
you may want to replace that part or test it at the very least.

Yes, that's what I was thinking, as everything indoors seems to be good. I will test that end of the coax also, but how does one test the box itself?

Hello again, Dagwood

Sorry you are having more trouble. Those two channels are very weak; it doesn't take much to knock them out.

You told us about your power inserter, but you didn't tell us what model of preamp you have.

You also didn't tell us what antenna you have. If you don't know the make and model, can you show us a photo of your antenna?

One thing might be different now: The trees might be thicker and taller now, so even if the leaves have fallen, the signals might be having a harder time now getting through.

If your antenna is made by Winegard, this video will show you how to check the CB8269 balun /combiner:

https://www.youtube.com/watch?v=TlQk...ule1MX8jCAfvPQ

http://forum.tvfool.com/attachment.p...1&d=1499537712

http://forum.tvfool.com/attachment.p...1&d=1499537896

http://forum.tvfool.com/attachment.p...1&d=1499538211

http://forum.tvfool.com/attachment.p...1&d=1499538454

You have checked the voltage coming out of the power inserter, but you haven't checked the voltage to the preamp at the upper end of the coax that connects to the preamp.

And you haven't checked the voltage to the preamp at the upper end of the coax when it is connected to the preamp. This is harder, because when you check the voltage to the preamp near the preamp when it is connected, you need access to the center conductor. I use a T-adapter for that:

http://forum.tvfool.com/attachment.p...8&d=1511635684

This is for an RCA preamp, but the method is the same:

http://forum.tvfool.com/attachment.p...9&d=1511636090

http://forum.tvfool.com/attachment.p...0&d=1511639045