Why Can’t I Receive Channel 19 - Non Valkyrie Related

[carolinarider09]

While I do not watch a lot of “network” TV, I do like the notion of being able to receive OTA (Over The Air) TV signals in case the internet fails.

And since I am an Amateur Radio Operator, I am supposed to know something about antennas and amplifiers and making connections work.

When I built the house I did sort of plan for a connection from the outside to my TVs and my FM radio and my Weather Radio. 

Up till about five or six years ago (not really sure) when all the TV stations changed for Analog to Digital signals, I lost Channel 19.  It was about the same time I re-did the antenna connections and amplifier configuration since I dropped DirectTV. 

Over the last few days, I replaced the antenna pre-amp and the in-house distribution amp with new units from Channel Master.  Figuring that the old amp had something that was blocking the new digital signals.  Still cannot pick up Channel 19 (500 Mhz).

The antenna is only about 20 feet up but it has a reasonable clear view of the locations of the transmitters from Channel 19.  As an aside, Channel 10, 25, 35 and 57 are easily received.  Distance from my antenna to the Channel 19 antenna is about 42 miles.  About the same distance as the other stations.

Oh, the old antenna was a small Channel Master antenna.  The new antenna is also a Channel Master but much larger (therefore should be better reception). 

I was wondering “What did I miss?”   

So, I thought I’d ask that question here. 

Why can I not receive one out of five channels who have their antennas located in about the same direction and, as I said, around 45 miles ways?

Oh, there have been occasions when I have be able to get channel 19 but, again, I cannot attribute that to weather or some other phenomenon.

I wondered if there might be some other “thing” in the house that generates a 500 MHz signal that might interrupt the TV station’s signal. 

Anyone have any “thoughts” or “reasons” for this?

BTW, there are four (4) TVs and two TIVO systems being fed from this distribution system.  All don’t receive channel 19.  But they all do receive the other channels listed above.

[scooperhsd]

Is this channel 19 the "analog" channel it started on (that is now the "virtual" channel), or is that the actual digital channel ? Yes - it is possible that it is both.

Also, rather than some of the other sites, I'd recommend using rabbitears.info for where to point / expected signal strength. I've been playing with OTA reception since 2000 and I haven't found much that works at 40+ miles. and even if it did - my antenna was at about 30-35 feet AGL (outside - not in an attic type situation).

[HayHauler]

About the only thing I can think of is that there is some obstruction in the exact heading from your place to the Channel 19 antenna.  If the others are very near the Channel 19 antenna, there shouldn't be any difference in the signal strength.
I don't believe that the FCC allows analog TV signals any longer.  They canceled all of those licenses I believe.

Hay 
Jimmyt

[Pluggy]

Stations use their old analog channel number as a brand name. The station you want may be transmitting on another channel today.  You have to look it up.  And unless a station is quite powerful, 40 miles may be beyond the capability of your equipment. 

[GiG]

  Directionality  


We have a similar situation- Fox2 is ~40 miles away & just doesn’t want to be receptive on any antenna    - accessible on cable, highly elusive OTA



   
   
Why Can’t I Receive Channel 19 - Non Valkyrie Related
« on: Yesterday at 06:32:11 PM »
Reply with quoteQuote
While I do not watch a lot of “network” TV, I do like the notion of being able to receive OTA (Over The Air) TV signals in case the internet fails.

And since I am an Amateur Radio Operator, I am supposed to know something about antennas and amplifiers and making connections

Over the last few days, I replaced the antenna pre-amp and the in-house distribution amp with new units from Channel Master.  Figuring that the old amp had something that was blocking the new digital signals.  Still cannot pick up Channel 19 (500 Mhz).

…

Oh, the old antenna was a small Channel Master antenna.  The new antenna is also a Channel Master but much larger (therefore should be better reception

Here’s your problem. Size Matters, but inversely proportional to the way you are thinking: Bigger is Not Better!
Look at an antenna. See the different size elements. Which ones do you think are for high frequency reception? (The smaller elements are for higher frequencies) -  old antenna was probably tuned closer to 500 MHz - return to an appropriate 500MHz Antenna. Your 400MHz job will probably work for CH19…

[Pluggy]

There are websites that have a calculator for building a yagi antenna for a specific frequency.  Years ago I built a 7 element yagi out of stuff in my garage.
 
 Worked great but was not hurricane-proof.

Any ham could do this easily.

[carolinarider09]

There are websites that have a calculator for building a yagi antenna for a specific frequency.  Years ago I built a 7 element yagi out of stuff in my garage.
 
 Worked great but was not hurricane-proof.

Any ham could do this easily.

Yes, you are correct.  I have built several antennas for 2 meters and 440 MHz. Actually they were designed for satellite communications.  And yes, I could try and build one for 500 MHz, but I was trying to  just do it the "old fashioned" way.   And make it useable should I not be here any longer (wife and children might just want to move here).

And I had considered, at least once, taking my 440 MHz antenna and just seeing what it would do. 

Regarding station location.  The picture of the map below shows the locations of the four stations in question.  Channel 10, 19 and 25 are the three located together.  They are less than 45 miles away. 

The "Dot" closer but in the same "bean" is channel 35 which I can also receive with no issues (PBS).




Channel 10 is on 192-198 MHz
Channel 19 is on 500-506 MHz
Channel 25 is on 536 -542 MHz
Channel 35 is on 596-602 MHz

[Pluggy]

Gotta look it up. When channel 5 Raleigh moved to UHF (35 I believe) they went down in power to 29kw. Cable subscribers never noticed as they still called themselves Channel 5.  The only OTA station I can get now is Fayetteville 22 miles away.  Not interested in their particular programming.

[carolinarider09]

I will give it a look (power output). If I remember correctly, Channel 19 was not lower than the others. 

Here is the antenna I mounted.   it's a Channel Master CM-3020. 

Average Gain:

VHF Lo: 3.6 dB
VHF Hi: 8.6 dB
UHF:  9.6 dB

Channel 19 falls under the UHF name as do channels 35 and 25.

[scooperhsd]

#1 - all the ranges stated on commercially available OTA antennas are exagerated. DARN FEW can actually pull in signals 100 miles away  - in fact 40 miles is often pushing it - even on the best in ideal circumstances ...

[carolinarider09]

#1 - all the ranges stated on commercially available OTA antennas are exagerated. DARN FEW can actually pull in signals 100 miles away  - in fact 40 miles is often pushing it - even on the best in ideal circumstances ...

 

[scooperhsd]

Are you using any preamps / distribution amps ?

My preferences would be to use a preamp (20-30 dB) coming off the antenna (if the antenna does not have a builtin amp), then, IF you need a distribution amp - something just enough to make up for cable loss. This would include the splits in your cables as well (hopefully none).

[HayHauler]

That is a pretty impressive antenna for TV.  It appears that the UHF boom/elements are very directional.  But, based on your map and distance, the bandwidth should be within that antenna's beam width.

You should be receiving all of those channels, especially with all of the pre-amps you have inline.

Hay  
Jimmyt

[Oldfishguy]

I cut the cable/satellite dish a few years ago. I'm about 50 miles from the local broadcast stations, live in the woods where the trees are taller than my house.  I had a local small shop (1 man and his mom) antenna/radio sales guy come out for a look at my possible digital reception.  He went up on the roof and found the best place to put an antenna with a booster for reception.  Not really where I wanted it but it was the best spot.  He installed new cable with no splices to the main TV and spliced to the secondary TV from there.  Works perfect, and many more channels being broadcast digitally than I thought. 

The cost was $600, everything included and done in a few hours.  Sometimes it is better to have a professional take a look.

Best of luck.

[GiG]

LPA - Log Periodic Antennas are  directional, need to be aimed… 

I charge only $500 to advise the best spot for LPA is - on the roof…   

[carolinarider09]

Are you using any preamps / distribution amps ?

My preferences would be to use a preamp (20-30 dB) coming off the antenna (if the antenna does not have a builtin amp), then, IF you need a distribution amp - something just enough to make up for cable loss. This would include the splits in your cables as well (hopefully none).

Yes an antenna pre-amp and a distribution amp. 

The distribution amp has four outputs.  I don't remember (and I cannot find the diagrams I drew up a few years ago so I could answer that question) but, there are four TVs on the system and two TIVO devices.  I think the TIVO devices are fed from one output that is split for the two devices.   

But I have only checked the TVs for reception of Channel 9.  The TIVO devices had the same problem, so I assume it's still there. 

[Rams]

Being completely honest about it, I've lost interest in just about everything that's put on our television screen now.   I don't trust the major news networks and even the weather person only gets it right about half the time.   TV is simply not that important to me any longer.  

Admittedly, I do watch TV for the movies when I'm bored.  

Rams

[Pluggy]

You want WLTX?  They are on RF channel 15.  They are on cable channel 19.  You may want to call and ask if they transmit directionally.  The transmission pattern may not be pointed your way.

[carolinarider09]

You want WLTX?  They are on RF channel 15.  They are on cable channel 19.  You may want to call and ask if they transmit directionally.  The transmission pattern may not be pointed your way.

Really?   I have picked up WLTX on Channel 19 on the TV occasionally but very weak signal and the video is very unstable. 

However, I will see what Channel 15 on the TV brings in. 

I will also contact them regarding signal direction.  For some reason, I thought that most TV stations used omni-directional vertical antennas.

[Pluggy]

Sure.  Have a look and you will see that WLTX is 700KW (powerful) with the prominent pattern lobe at 210 degrees.  That means Aiken, not you.  https://publicfiles.fcc.gov/tv-profile/WLTX

I recall a Florida TV station, maybe more than one, with an antenna pattern designed to cover both Orlando and Daytona Beach, 50 miles apart.  The transmitting antenna was located between the two cities.

[Pluggy]

From a mile away, that TV transmit antenna looks like a simple vertical stick that radio hams are familiar with.  It is actually a large cylinder containing transmitting elements.  Some of those assemblies weigh well over a ton.

[carolinarider09]

I thought that most TV stations used omni-directional vertical antennas.

From a mile away, that TV transmit antenna looks like a simple vertical stick that radio hams are familiar with.  It is actually a large cylinder containing transmitting elements.  Some of those assemblies weigh well over a ton.

I thought about the above after I sent my reply. 

I have not contacted WLTX yet but I will.  They say they serve Columbia, SC.  The only other CBS stations around are in Greenville, almost 180 degrees from where the antenna is pointed now.

[HayHauler]

Totally unrelated, but still something cool.  These high power stations don't use coax like us hams usually think of, they use something called waveguide, which is usually a large pipe that the signal from the transmitter uses in transit to the antenna at the top of the tower.  The ideal situation is to place the transmitter at the top of the tower with only a short run of transmit cable to the nearby antenna.

Hay 
Jimmyt

[carolinarider09]

Yes, I have heard the term "wave guide".  Never really looked into it. 

And it would seem to be a simple step to put the transmitter at the top of the tower.  Only issue wold be "transmitter" maintenance.

I looked online a few days ago and found that WLTX also had a digital transmission (I think it was mentioned above) that broadcast on Channel 15.  I tired that chance as well and nothing.

The Sony TV I have is susppsoe to be able to receive digital signals as well.  (I checked the three other TVs that are older, still no channel 19). 

Well, as I think I said above, I can get Channel 19 programs (the ones I want to watch) on my Paramount App. 

I will continue to work or look into the issue after Christmas.

Merry Christmas to all!

[HayHauler]

Yes, I have heard the term "wave guide".  Never really looked into it. 

And it would seem to be a simple step to put the transmitter at the top of the tower.  Only issue wold be "transmitter" maintenance.

I looked online a few days ago and found that WLTX also had a digital transmission (I think it was mentioned above) that broadcast on Channel 15.  I tired that chance as well and nothing.

The Sony TV I have is susppsoe to be able to receive digital signals as well.  (I checked the three other TVs that are older, still no channel 19). 

Well, as I think I said above, I can get Channel 19 programs (the ones I want to watch) on my Paramount App. 

I will continue to work or look into the issue after Christmas.

Merry Christmas to all!

Merry Christmas CR09!
and 73's.

Hay 
Jimmyt
K5JTJ

[Pluggy]

The ideal situation is to place the transmitter at the top of the tower with only a short run of transmit cable to the nearby antenna.

What stations have the actual transmitter on the tower?  The UHF TV transmitters I am familiar with are big consumers of electrical power.  To power a 700KW transmitter and the cooling system for it would require a long run of heavy conductors up a 2000ft tower plus additional wiring for instrumentation and controls.  Waveguide going up the tower to the radiating array is how I have seen it.

[scooperhsd]

Raleigh NC has a tower that can accomodate 6 transmitting antennas on it - all at once. I'm not sure how many are on it, but while we were there Capital Broadcasting made a big deal about that tower. What made Raleigh real nice for receiving OTA is that all stations (except PBS and ION) are located within .5 mile of each other. The 2 PBS stations each were about 35-40 miles from us, and we were about 1/2 mile from a line drawn between them.

[HayHauler]

Here is a site that shows the big sticks and some of the transmitters.  There is a whole floor devoted to "combiners" that takes the signals from several transmitters, combines them, and sends them up the towers.  Waaay over my head...

https://www.fybush.com/site-20201002/

Hay  
Jimmyt

[carolinarider09]

Here is a site that shows the big sticks and some of the transmitters.  There is a whole floor devoted to "combiners" that takes the signals from several transmitters, combines them, and sends them up the towers.  Waaay over my head...

https://www.fybush.com/site-20201002/

Hay  
Jimmyt

Ahhhh "combiner"..... I remember that term but....  it has been awhile.

[GiG]

I think it’s a form of multiplexing allowing for transmittal of a package containing multiple signals to be
Decoded un in combined) at  a remote site

[HayHauler]

You are correct Gig!  That limits the runs of wave guide required to deliver the signal(s) to the top of the tower.  That transmitter facility has one whole floor devoted to combining signals. 

Hay 
Jimmyt

[lakehunter]

FCC data on WLTX, 

TV Station Profile WLTX Station RSS - All documents (Opens in new browser window) WLTX COLUMBIA, SC

    Virtual Channel 19 Frequency 476.0 RF Channel 15 Facility ID 37176

I am between Chapin and Little Mountain in a lower area between two ponds. Using same antenna as yours with a 20 Db mast mount amp and rotator 10ft above roof top. Get all Columbia stations including the 8 individual ones from WLTX. Numbered 19.1 - 19.8 but actually on the over the air ch 15 using a auto tuner search. That antenna set up when aimed right will get Charleston and Charlotte along with Greenville / Spartanburg. If you are not able to get it in there may be something blocking the signal, I once had a similar issue with a "leaky" SCEG transformer set up on a nearby pole causing a RF shield effect, they came and did a line test and quickly changed out the xfmrs and insulators.
Good luck with the bug chase, Lakehunter - KQ4PW 

[GiG]

Hay, JimmyT: Thanks for verifying what I thought! I really have no first hand experience with combiners, I only posted what I thought it could be based solely on the name.   
 

[carolinarider09]

FCC data on WLTX, 

TV Station Profile WLTX Station RSS - All documents (Opens in new browser window) WLTX COLUMBIA, SC

    Virtual Channel 19 Frequency 476.0 RF Channel 15 Facility ID 37176

I am between Chapin and Little Mountain in a lower area between two ponds. Using same antenna as yours with a 20 Db mast mount amp and rotator 10ft above roof top. Get all Columbia stations including the 8 individual ones from WLTX. Numbered 19.1 - 19.8 but actually on the over the air ch 15 using a auto tuner search. That antenna set up when aimed right will get Charleston and Charlotte along with Greenville / Spartanburg. If you are not able to get it in there may be something blocking the signal, I once had a similar issue with a "leaky" SCEG transformer set up on a nearby pole causing a RF shield effect, they came and did a line test and quickly changed out the xfmrs and insulators.
Good luck with the bug chase, Lakehunter - KQ4PW