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Way OT: Over the Air Broadcast TV

Bill, why (how) could any of the above possibilities suddenly and independently occur in all three boxes at the same time?

There's something in the antenna or its wiring scheme itself.
 
Stone said:
Bill, why (how) could any of the above possibilities suddenly and independently occur in all three boxes at the same time?

There's something in the antenna or its wiring scheme itself.
Click to expand...

Well, it can't be an overload of channels because the scan will not even start when connected to the roof antenna. But it is now obvious the problem now lies somewhere in a incompatability between the roof antenna and these set boxes.

Just as a test, I disconnected three of the four boxes and it had no effect on my results from an earlier post. I did run an "additive" scan while on the rabbit ears and it found about 9 more channels, so I am up to about 45 now. Tonight at dinner I had the TV hooked up to the roof antenna and used the box (and the channels saved from the rabbit ears scan). Everything worked, so obviously the box likes working with the roof antenna. I just have no idea what could have changed over the past few days.

To answer another question posted above, there has been no change to any of the sets or wiring. The same four sets have been on this antenna for years. The antenna itself may date back to the Carter administration!

I may have to go onto the roof and physically inspect the antenna wiring. Over the past couple years a few parts have fallen off the antenna but it continues to work as before. Probably because we almost have line of site to the broadcasting antennas in New York City.

Thanks...Joe
 
My guess is something has messed with the impedance of your roof antenna.

It could be something mechanical on the antenna itself (i.e. water ingress to the connector housing). It also could be something like a mouse/rat has chewed part of the way through a cable somewhere in your roof. Also could be a fault with one of the splitters for the 4 TV's etc etc.

The faults your describing sound very much like a poorly designed set top box is failing in ways that were not anticipated for.
 
There should also be an option for a "manual scan" that lets you cycle through all possible RF channels and add/delete regardless if anything is on that channel. (although it is kind of hard to know what RF channels match up to the station numbers)
 
Stone said:
Bill, why (how) could any of the above possibilities suddenly and independently occur in all three boxes at the same time?
Click to expand...

I never said it would account for that. And I did state that I really didn't know anything.

I apologize to the list members for "adding to the noise with no meaningfull information." Sorry I made everyone read my inept comments.

Stepping aside.

Bill
Smithville, NJ
 
i almost never watch TV. but pondering this thread I turned on the tv today. Only half my channels are working and when I check the signal strength on any working or nonworking channel, the meter is regularly oscillating from zero or some other low number, to full scale, and back again. Hopefully I geta chance to investigate this. I won't chance an auto scan in case I am having the same problem.
 
OTA signal strength is fine in my locations (I can see the antennas for at least two of the stations two ridges over). Even without an antenna of any sort, I can still get reception on a couple of channels on my other box. Nothing with the RCA box at all, with or without the antenna. The scan completes with no channels registered.
 
SomeGuy said:
.. (although it is kind of hard to know what RF channels match up to the station numbers)
Click to expand...

This actually is pretty easy to find out, thanks to the FCC's TV Query

Scroll down to 'stations within a radius' and enter a radius and your coordinates (or use the link for reference coordinates of communities). The actual channel is output in all of the lists, regardless of the 'channel branding' that the station may be using.

The same functions are available, incidentally, with the AM Query and FM Query pages; I have spent the last twenty-five years either full-time or contract as a broadcast engineer, and when I was full-time these pages and their precursors were my bread-and-butter.

(And, in case anyone was wondering, my avatar is related to one of the oldest transmitters I worked on... it's an RCA 892R power triode which weighs many pounds and stands about two feet tall.... typical application had two 10VAC filament transformers at 50A in quadrature (to eliminate hum) with a plate voltage around 10KV with up to 2A plate current, 4KW max plate dissipation and 12KW max signal plate input power; for an AM these things were used for 5KW transmitters as a single-end class C RF plate modulated output amplifier driven by two of them in class B push-pull as the modulator....... <insert Tim Taylor grunt here> Now that's vintage, since that transmitter was built in 1946.)

Also somewhat incidentally, and speaking of vintage, back in 2000, the FCC released a massive archive of code from an old VAX, and if anyone wanted to play with some vintage FCC FORTRAN code for a VAX (including some web CGI scripts in FORTRAN!) I still have that archive (38MB uncompressed as I recall). EDIT: The FCC still has the page with the archive up and online; see https://transition.fcc.gov/oet/info/software/vaxcode/ (7.7MB compressed ZIP, even though the page itself says 7.8kB, it's wrong) .
 
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To answer a question raised earlier; while I can manually select a channel, if that channel has not been saved via a scan I cannot tune to it.

There have always been a number of oddities since the cutover to digital signals and the need to use these boxes. Before this latest issue arose, here are some...

Although all four TVs share the same antenna and use the same model RCA box, they would almost never "see" the same channels. Some would get channels the others could not receive.

Reception would vary by station and day. Some stations would alwyas come in pretty good, others would have good and bad days. Sometimes one TV would have no problem with a station while another TV would. I might somethime have to try multiple TVs to find one getting the best reception for that channel that day.

Here's the oddest one. I don't know if it still did this, but when I used to scan for channels I would get (among others) channels 5.1, 5.2, 9.1 and 9.2. On all but the kitchen TV channels 5.1 and 5.2 were the same except one was widescreen and one was standard. Same with 9.1 and 9.2. However, on the kitchen set, 5.1 and 9.2 were paired up, while 5.2 and 9.1 were paired up. That was the oddest thing I have yet seen. Different sets would get different reception for the same channels.

Joe
 
That's pretty normal in the typical residentialantenna wiring. Your antenna is probably a lousy match for the signals you are trying to recieve and the feedline may have multiple opens and shorts. What is also common is tees that aren't really signal splitters and may have unterminated connections.

The end result is what you have. A usually adequate antenna system that has quirks.
I still think your receivers are receiving something they shouldn't, which is causing them to abort scanning.
 
Grandcheapskate said:
Here's the oddest one. I don't know if it still did this, but when I used to scan for channels I would get (among others) channels 5.1, 5.2, 9.1 and 9.2. On all but the kitchen TV channels 5.1 and 5.2 were the same except one was widescreen and one was standard. Same with 9.1 and 9.2. However, on the kitchen set, 5.1 and 9.2 were paired up, while 5.2 and 9.1 were paired up. That was the oddest thing I have yet seen. Different sets would get different reception for the same channels.
Click to expand...

Fox owns both Channel 5 (WNYW) and Channel 9 (WWOR-TV) in the NYC area, so their subchannels offer a simulcast of each other, so that viewers can watch both stations even if they can only pick up one of the two signals in their area.
 
KC9UDX said:
That's pretty normal in the typical residentialantenna wiring. Your antenna is probably a lousy match for the signals you are trying to recieve and the feedline may have multiple opens and shorts. What is also common is tees that aren't really signal splitters and may have unterminated connections.

The end result is what you have. A usually adequate antenna system that has quirks.
I still think your receivers are receiving something they shouldn't, which is causing them to abort scanning.
Click to expand...

That coupled with signal reflections due to an urban area probably causes the weird channel allocations when scanning. The unterminated / bad splitters would also explain why some set top boxes had great reception and others had zero.
 
Here's one that just happened this afternoon. Using the iView box, I couldn't change channels. The thing did respond to the front-panel on/off button (it seem to be kind of silly to call it a "power" button, since it has nothing to do with the power supply). Rescanned the channels, nothing discovered. Unplugged it from the AC outlet, rescanned, it worked fine.
 
Is there a signal strength meter on the box? Perhaps when scanning for channels with the rabbit ears you're getting a higher power signal with the rabbit ears while scanning than you do with normal viewing on the other antenna. I know a couple of our TVs with ATSC tuners built-in will show the received signal strength. Also remember that going through an antenna splitter is not a lossless exercise... you will end up with ~3db loss in a 2:1 splitter, more necessarily with a 3:1 or 4:1. You might need a signal amplifier and/or your roof antenna points in the wrong direction/orientation. Have you checked this website for your area? http://antennaweb.org.

What time of the day are you scanning? Terrestrial OTA broadcast reception is almost always better at night.
 
geoffm3 said:
Is there a signal strength meter on the box? Perhaps when scanning for channels with the rabbit ears you're getting a higher power signal with the rabbit ears while scanning than you do with normal viewing on the other antenna. I know a couple of our TVs with ATSC tuners built-in will show the received signal strength. Also remember that going through an antenna splitter is not a lossless exercise... you will end up with ~3db loss in a 2:1 splitter, more necessarily with a 3:1 or 4:1. You might need a signal amplifier and/or your roof antenna points in the wrong direction/orientation. Have you checked this website for your area? http://antennaweb.org.

What time of the day are you scanning? Terrestrial OTA broadcast reception is almost always better at night.
Click to expand...

Yes, there is a signal strength test on the MENU. I don't have the rabbit ears connected any more so I can't compare the two at the moment. It's been a couple days since I did the scan with the rabbit ears and so far all the channels are holding with the roof antenna connected. Any attempt to scan for more channels just hangs, but I don't lose the ones I already saved.

The antenna wire comes into the house and is then spliced at one point to split into the four wires leading to each TV. Like I have said, nothing has changed in the house since the cutover to digital years ago. But it seems pretty obvious the problem is with the roof antenna and I'll just have to go on the roof and check the connections. Maybe it's time for a new antenna - they still sell them????

Joe
 
Yes, they still sell them. They aren't too expensive, neither.

You probably don't want a VHF/UHF like you probably have now though. I have a Radio Shack 8-bay bowtie that I bought two years ago, and I'd highly recommend it but it looks like they don't sell it anymore.

A new high-gain UHF antenna will be much better suited for today's broadcasts than an older VHF/UHF one.

Replace the antenna, check all connections (especially for corrosion) and if you still have the problem, see if you can borrow a frequency counter to plug into it.
 
A motorized antenna on my room was the best thing I ever did for FM and TV reception. Thing is they don't last forever, a couple of the metal pieces broke off after a storm a few years back and I don't think it rotates anymore (this thing is like 10+ years old). Good thing its located where I need it and reception rocks.
 
KC9UDX said:
...
A new high-gain UHF antenna will be much better suited for today's broadcasts than an older VHF/UHF one....
Click to expand...

Actually, some high-band VHF stations got to keep their VHF channel, and so high-band (170-220MHz) reception is still useful. While many UHF antennas will have some gain even at one-third of their design frequency, the pattern is going to be less than optimal. The only station I can reliably receive in my area is a high-band VHF, and its antenna is more distant than three UHF stations' antennas (a UHF station on the same tower as the VHF station does not have usable signal, even). So my 22-year old Radio Shack mid-range VHF-UHF log-periodic is still very much used, with a 15 year old rotator, even.
 
The NYC market has 3 major networks on VHF still, WABC 7 (ABC), WPIX 11 (WB), and WNET 13 (PBS). NYC's new MeTV affiliate, WJLP, is broadcasting from VHF 3. No clue how far their signal travels. Otherwise VHF-Lo is empty besides an LPTV analog station on VHF 6 acting as a radio station (WNYZ-LP).
 
Low band VHF is still being used for DTV, although digital suffers much more badly from summer night DX propagation than analog did.
As mentioned by NJRoadfan, NYC has MeTV affiliate WJLP (licensed to Middletown, NJ but transmitting from NYC) on channel 3 (virtual channel 33). Philadelphia has ABC WPVI-TV on channel 6, Atlantic City has ex-NBC WACP on channel 4, and Wilmington, DE has MeTV KJWP (moved in from Jackson, Wyoming) on channel 2.
 
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