No reception

dabadooyaa

DTVUSA Jr. Member
#1
My mother and father have not been able to get reception on their t.v since the first of January. The converter is a Magnavox and worked all of 2009. Got at least five stations. We live in Roxboro, NC about fifty miles north of Raleigh. They tried a brand new extra Magnavox that they purchased and it does not work. My husband got up on the roof this past weekend and took down the grid antenna that they purchased when this ____started and he could not find anything wrong with wires, etc. He even carried a VCR up on the roof and plugged that in using the cable from the antenna. The VCR worked. I hope that I'm making since. We've rescanned, checked everything. Booster doesn't even help get a channel like it did before. Does this sound like we need a converter, amplifier on the antenna, or what? If so, what brand? We searched and searched and you can't find Timax or ChannelMaster. HELP!
 

FOX TV

Contributor
#2
Hello,

the reception experts on here need a little more information in order to help you solve your issues. Please visit this section of this forum on how to get started in asking for help on reception issues. http://www.dtvusaforum.com/dtv-hdtv...n/18697-getting-started-over-air-tv-faqs.html

The main information needed is the data you will find by visiting www.tvfool.com. Look for the start here text button on that site. You may also find similar data at www.rabbitears.info, and either one will give us the information we need to start the troubleshooting process.
 
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Don_M

DTVUSA Member
#3
Hi,

We've got a couple of threads here with advice that might help you determine if the converter box is at fault:

• http://www.dtvusaforum.com/converte...rter-box-has-no-power-suddenly-turns-off.html

• http://www.dtvusaforum.com/converte...your-converter-box-try-memory-erase-scan.html

These are the easiest troubleshooting steps, so they should be tried first. Unfortunately, a lot of boxes are having reliability issues this year. This is especially likely if the top of the Magnavox converter's case feels unusually warm after it's been in use for a while.

If these tips don't help much, connect a pair of set-top "rabbit ears" to the box and re-scan for channels. If rabbit ears yield any reception at all, that suggests the fault lies with either the downlead cable and/or the coaxial transformer, which allows the cable to be hooked up to the antenna's terminals.

Good luck, and let us know what happens! :thumb:
 

dabadooyaa

DTVUSA Jr. Member
#4
The converter does come on and ocassionally we have been able to find a channel. But we can only get one if it at night time or very early in the morning. And we have rescanned a million times.
 

Don_M

DTVUSA Member
#5
The memory erase scan would still be worth a try, and only takes about 15 minutes to perform. These boxes are little computers that, like a laptop or desktop that starts acting "funny," may need a full re-set now and again to clear up operating issues. Re-scanning by itself doesn't go far enough.
 

dabadooyaa

DTVUSA Jr. Member
#6
Sorry, I'm brain dead. This has worried me for so long now. When I said that I had rescanned, I meant that I had done the double-scan a million times. But I did not keep it off 5 minutes. Does that make a big difference?
 

dabadooyaa

DTVUSA Jr. Member
#8
I've updated some info from TVFool. I hope this helps. I'm mostly trying to get the stations in the 150 - 180 degree azimuth ranges but I would also like to receive channel 4.1 at 202 degrees and channel 2.1 at 242 degrees.

 
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Tim58hsv

DTVUSA Member
#9
They should be getting a lot more than five channels or less since everything on the TVFool site listed under the NM (db) column that is 0.8 and above should come in (in theory at least). Seriously, they should have been getting a lot more than five channels before which tells me there's something wrong in the line from the antenna to the converter box to the tv.
Whatever it is just got worse.

Try removing the booster from the line to see if that helps since a bad booster could block the signal. If that don't fix it check all the coaxial wiring for a bad connection. It could be a bad connection inside the wall plate that you connect the cable to.

Other than that, I don't know what to suggest but I suspect the converter boxes are not the problem since they've tried two different ones already.

Good luck and keep us posted.
 

dabadooyaa

DTVUSA Jr. Member
#10
Daddy doesn't have a booster on the antenna. He had an amplifier connected to the converter, but we disconnected that, since it didn't seem to be working. Also as I mentioned in my first post, Danny carried a VCR up on the roof and plugged the cable that's connected to the antenna and the VCR worked. Doesn't that mean that the cables are fine?
 

dabadooyaa

DTVUSA Jr. Member
#11
Please excuse my stupidity. You mean the wall plate where the cable is inside the house. Sorry. I'm learning though. My husband should be sending these messages, which he did concerning the signal map. Thanks. Don't desert us.
 
#12
I don't see how a VCR can be useful for testing since they have analog tuners and all your signals are digital.

However, on the off chance if might have a digital tuner, testing it on the roof where it "worked" and assuming that it didn't work indoors would indicate that the cable feed from the antenna is the problem, not the antenna or the converter box.

If you can identify the antenna (perhaps a photo of it if you don't know the make and model), it would also be helpful.
 

FOX TV

Contributor
#13
I don't see how a VCR can be useful for testing since they have analog tuners and all your signals are digital.

However, on the off chance if might have a digital tuner, testing it on the roof where it "worked" and assuming that it didn't work indoors would indicate that the cable feed from the antenna is the problem, not the antenna or the converter box.

If you can identify the antenna (perhaps a photo of it if you don't know the make and model), it would also be helpful.
Also, if you had a VCR with a digital tuner, you would not really need to use the converter box. You could simply use the tuner in the VCR, and not worry about the converter box at all, but only if it has a digital tuner built in.
 
#14
I haven't found any VCRs yet with a digital tuner although there are some DVD-R/VCR combos that do have them. However, they are both expensive and rare and it's not very likely that is what the OP has.
 

FOX TV

Contributor
#15
They do exist !

I haven't found any VCRs yet with a digital tuner although there are some DVD-R/VCR combos that do have them. However, they are both expensive and rare and it's not very likely that is what the OP has.
I saw one at Bestbuy a few weeks ago that did have a Digital Tuner in it. I was a VCR/DVD recorder combo. Model: RC897T | SKU: 8715367. There are other models available too.

LG - Multiformat DVD-R/-RW/+R/+RW/RAM Recorder/4-Head Hi-Fi VCR Combo
Plays VHS, DVD, DVD+R/RW, DVD-R/RW, CD, CD-R/RW, MP3, WMA, JPEG and MPEG-4 formats; VHS-to-DVD and DVD-to-VHS recording; 1080p upconversion; virtual surround sound support
 

FOX TV

Contributor
#16
Equipment problems !!

I've updated some info from TVFool. I hope this helps. I'm mostly trying to get the stations in the 150 - 180 degree azimuth ranges but I would also like to receive channel 4.1 at 202 degrees and channel 2.1 at 242 degrees.

From what I see on your TV FOOL data, you must have some type of equipment issue. Your signal levels and path obstructions all look very good. You should be able to pull in the 150 to 180 degree signals without an amplifier. Even the station I work for is listed with a 1 edge obstruction, and could possibly be receivable with an elevated antenna above 30 feet or so.

I do see something that makes no sense though, and that is the listing for WSET and WWCW. WSET is listed as line of sight, and WWCW is listed as one edge, but these transmitters are located on top of the same mountain, and the only difference is about 200 feet in elevation difference between the two antennas. Strange !!
 
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Tim58hsv

DTVUSA Member
#17
Also as I mentioned in my first post, Danny carried a VCR up on the roof and plugged the cable that's connected to the antenna and the VCR worked. Doesn't that mean that the cables are fine?
Do you mean that he put a tape in the vcr, disconnected the cable from the antenna and hooked it to the vcr in order to see if the television was getting a signal? If so that's a pretty clever way to check for bad wiring. And if that's what he did then the coax may not be the problem after all.
 
#18
I saw one at Bestbuy a few weeks ago that did have a Digital Tuner in it. I was a VCR/DVD recorder combo. Model: RC897T | SKU: 8715367. There are other models available too.

LG - Multiformat DVD-R/-RW/+R/+RW/RAM Recorder/4-Head Hi-Fi VCR Combo
Plays VHS, DVD, DVD+R/RW, DVD-R/RW, CD, CD-R/RW, MP3, WMA, JPEG and MPEG-4 formats; VHS-to-DVD and DVD-to-VHS recording; 1080p upconversion; virtual surround sound support
Yep. $250.

Do you mean that he put a tape in the vcr, disconnected the cable from the antenna and hooked it to the vcr in order to see if the television was getting a signal? If so that's a pretty clever way to check for bad wiring. And if that's what he did then the coax may not be the problem after all.
If this is what is done, it would certainly prove that the cabling can carry a channel 3/4 VHF signal at around -25 to -15 dBm. However, there might be possible faults int he cable that will allow this gross test to pass while still causing a failure of the OTA signals to make it through.
 

FOX TV

Contributor
#19
Yep. $250.



If this is what is done, it would certainly prove that the cabling can carry a channel 3/4 VHF signal at around -25 to -15 dBm. However, there might be possible faults int he cable that will allow this gross test to pass while still causing a failure of the OTA signals to make it through.
Another way to test a coaxial cable for an open conductor condition is to short the conductors together on one end, and use an ohm meter to check for continuity on the other end between the shield and center conductor.

The VCR idea was also a good and ingenious way to see if the cable would pass a VHF RF signal, but it tells you nothing about the UHF capability of the cable, as UHF signals get attenuated much quicker in a coaxial cable than do VHF signals.

I would also look at cable and antenna degradation from weather, or if mounted on a chimney, it could have some corrosion problems from heating exhaust. I have seen aluminum antennas literally fall apart from corrosion from oil heat chimney exhaust. If the antenna uses a balun, it could also be bad from water infiltration and freezing, and that could cause signal issues that could be intermittent.

Take everything out of the system such as splitters, amplifiers and get it down to basics and this can eliminate many possible failure points and hopefully help you find the problem.
 

dabadooyaa

DTVUSA Jr. Member
#20
Do you mean that he put a tape in the vcr, disconnected the cable from the antenna and hooked it to the vcr in order to see if the television was getting a signal? If so that's a pretty clever way to check for bad wiring. And if that's what he did then the coax may not be the problem after all.
Hey, this is Deb's husband. Yeah, I did check the signal by running the VCR back into the TV. I couldn't really see any signal degradation or interference with that method using a video tape. I did notice one of the other comments about VHF signals passing through. Good point. UHF and VHF are two different animals.

Also, someone mentioned about the balun and I would not have considered that as I purchased the in-laws a new DB8 grid antenna from Antennas Direct while routing new RG6 cable, and it has only been tripod mounted on the rooftop for about one year. I would be surprised if there was any rust internally. I assumed the baluns would be sealed to prevent water from entering. Can they get humidity build-up in them? We did get a fair amount of snow this winter (for the south) and typically get a fair amount of rain in the fall-winter. Looking at the antenna, it appears in excellent shape still.

This has just got me stumped. When I first did the install, it was getting pretty good signal readings on just about any station they wanted. However when the winter hit, everything went south. It's almost impossible to get any signals.

I think the only thing left to do is to route new RG6 coax and see if that could be an issue. I might try a test run from the antenna over the eave and through the front door before "chasing" it through with an electrical fish. If that's not the issue, I'll try opening up the balun and seeing if there is something fishy going on in there. I don't know what else it could possibly be.
 
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