Updated TV Antenna Thoughts

/ Updated TV Antenna Thoughts #121  
The flat one had an amp. I think something was off inside the plastic case, it had a rattle.

Tv has strength meter. New one full signal.
 
/ Updated TV Antenna Thoughts #122  
Thinking about repairing the uhf, low vhf parts of my old antenna, and pointing it at stations in other direction.
 
/ Updated TV Antenna Thoughts #126  
I have coupled a few multiple antennas and found that channel specific diplexers (combiners) offer less loss than a broad spectrum unit, antenna specialists should have a range to choose from.
 
/ Updated TV Antenna Thoughts #127  
Finally got the antenna up. 0311181453.jpg
 
/ Updated TV Antenna Thoughts
  • Thread Starter
#128  
Finally got the antenna up.

Hope it works out well for you. I am still enjoying mine. Has worked fine except for one station FOX 6 out of Birmingham. I sent the following picture to the guy I bought antenna from to see if he had thoughts on getting that station better. Based on the Broadcast Frequency of that channel (second column from left) he has suggested that I raise the antenna to better receive FOX 6. I plan to give that a try. This guy deals with over the air and antennas everyday but was interested in the source of my chart, as it gives the sub channels you can expect to receive. The site for the chart is TV Broadcast Tower Locator (OTA DTv) You simply enter your address and it will retrieve a map of the TV towers around you, and the chart of channels.

Sxs3dIX.jpg
 
/ Updated TV Antenna Thoughts #129  
Hope it works out well for you. I am still enjoying mine. Has worked fine except for one station FOX 6 out of Birmingham. I sent the following picture to the guy I bought antenna from to see if he had thoughts on getting that station better. Based on the Broadcast Frequency of that channel (second column from left) he has suggested that I raise the antenna to better receive FOX 6. I plan to give that a try. This guy deals with over the air and antennas everyday but was interested in the source of my chart, as it gives the sub channels you can expect to receive. The site for the chart is TV Broadcast Tower Locator (OTA DTv) You simply enter your address and it will retrieve a map of the TV towers around you, and the chart of channels.

Sxs3dIX.jpg

That is a good site. Are you saying you are getting all of the channels shown except the channel 6? If so, that is a bit puzzling since at -38 dbm it is the strongest channel on the chart at your location. And all of them are withing a few degrees of the same direction. so you should not need a rotor at all. Is your antenna pointed at 11 degrees from due North? Also it has the most transmit power at 1000 Killowatt (or 1 megawatt) of ERP (effective radiated power). This includes antenna gain at the transmitter and any losses in the feedline. I don't know what the dbm (decibels above or below a milliwatt) readings are calculated, unless it is into a standard reference antenna. They don't know how much gain your antenna has and how much loss is in the feedline. In this case into the standard antenna (maybe a dipole?) the signal should be -38 db below a milliwat of power if injected straight into the feedpoint.
 
/ Updated TV Antenna Thoughts
  • Thread Starter
#130  
That is a good site. Are you saying you are getting all of the channels shown except the channel 6?

I'm not sure of the exact point degree but house sits basically facing south. I have to have the antenna at the exact right spot for FOX 6, wind or weather will affect. Here is pic of antenna
aqlB6rB.jpg


I do get a lot of stations, many from Birmingham and a few from Montgomery. The next three pics are from the tower site, in order by channel number instead of angle from north. I am not there now but I have marked what I get===Circled BLUE comes in great, and circled RED either comes and goes or pixlates (msp). The guy helping me thinks getting the antenna farther above the roof might just help with FOX.

wqzhMT9.jpg

z7YHm6B.jpg

U2Iq2zb.jpg


Also, here are meanings of headings
tuqgRH2.jpg
 
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/ Updated TV Antenna Thoughts #131  
Im not getting one station, has always been tough to get.
 
/ Updated TV Antenna Thoughts #132  
Interesting that channel 13 at the same distance and same azmuth (bearing) is transmitting with 20 kw instead of 1000 kw and is projected to have a 12 dBm difference in signal you have marked in blue (good) yet the much more powerful signal from channel 6. Granted it is 48 meters lower in elevation, and the actual RF channel is 50 (UHF) instead of 13 (hi band VHF), but I would have thought it wouldn't have made as much difference. But I guess it does.
 
/ Updated TV Antenna Thoughts #133  
Interesting that channel 13 at the same distance and same azmuth (bearing) is transmitting with 20 kw instead of 1000 kw and is projected to have a 12 dBm difference in signal you have marked in blue (good) yet the much more powerful signal from channel 6. Granted it is 48 meters lower in elevation, and the actual RF channel is 50 (UHF) instead of 13 (hi band VHF), but I would have thought it wouldn't have made as much difference. But I guess it does.

It's got 50 times the power?
 
/ Updated TV Antenna Thoughts #134  
It's got 50 times the power?


Yep, according to the chart. 1000 KW ERP. Versus 20KW ERP. So yeah 50 times the power. Of course 50 times the power is not as much as you might think.

Lets look at the S meter on a standard communications reciever. Each S unit (if it used the old standard Collins calibration) is 6 dB

Going from 20 Kilowatts to 1000 Kilowatts is 17 dB of power increase So we are talking about almost 3 standard S units as you would see the signal on a communications receiver. So like S5 to almost S8. Or if a 20 KW signal was S9, the a 1000 KW signal would be 17 dB over S9. Those of you that have operated communications receivers hopefully this gives you some "feel" for this. Remember the dB scale is logarithmic. Those huge gains in transmitter power or antenna gain may not make as much difference on the receiver end as you at first think.
 
/ Updated TV Antenna Thoughts #135  
Yep, according to the chart. 1000 KW ERP. Versus 20KW ERP. So yeah 50 times the power. Of course 50 times the power is not as much as you might think.

Lets look at the S meter on a standard communications reciever. Each S unit (if it used the old standard Collins calibration) is 6 dB

Going from 20 Kilowatts to 1000 Kilowatts is 17 dB of power increase So we are talking about almost 3 standard S units as you would see the signal on a communications receiver. So like S5 to almost S8. Or if a 20 KW signal was S9, the a 1000 KW signal would be 17 dB over S9. Those of you that have operated communications receivers hopefully this gives you some "feel" for this. Remember the dB scale is logarithmic. Those huge gains in transmitter power or antenna gain may not make as much difference on the receiver end as you at first think.

Thanks!
 
/ Updated TV Antenna Thoughts #136  
I was missing out on the term ERP. Went and read up a bit. Makes more sense now. I was confusing transmitter power with ERP. Man, I'm rusty.
 
/ Updated TV Antenna Thoughts #137  
Interesting that channel 13 at the same distance and same azmuth (bearing) is transmitting with 20 kw instead of 1000 kw and is projected to have a 12 dBm difference in signal you have marked in blue (good) yet the much more powerful signal from channel 6. Granted it is 48 meters lower in elevation, and the actual RF channel is 50 (UHF) instead of 13 (hi band VHF), but I would have thought it wouldn't have made as much difference. But I guess it does.
I wonder if the higher frequency is the difference. I lost all of the San Francisco stations when they moved up to UHF a few years ago. Lots of tinkering with various antennas - nothing.

SF is over the horizon so apparently all my VHF reception was reflected off the atmosphere, and higher frequencies don't bounce as well.
 
/ Updated TV Antenna Thoughts
  • Thread Starter
#138  
I wonder if the higher frequency is the difference. I lost all of the San Francisco stations when they moved up to UHF a few years ago. Lots of tinkering with various antennas - nothing.

SF is over the horizon so apparently all my VHF reception was reflected off the atmosphere, and higher frequencies don't bounce as well.

That is what I am hoping. Guy helping has narrowed it down to that, thinking moving antenna to back of house will probably make no difference but raising antenna might.
Also a move to the back may hinder Montgomery stations to the south.
I should be able to raise it a good 10 feet, just got to get back up there with some help.
One other note: I installed in the fall/winter = no leaves on trees. Got fox 6 good and thought I had it fixed with exact antenna pointing. But now with spring I get nothing on that station.
 
/ Updated TV Antenna Thoughts #139  
If you click on one of the channels there's a terrain view at the bottom of the chart. See how that varies for the bad stations vs good that are in the same direction. That may help to see if height will help.
 
/ Updated TV Antenna Thoughts
  • Thread Starter
#140  
If you click on one of the channels there's a terrain view at the bottom of the chart. See how that varies for the bad stations vs good that are in the same direction. That may help to see if height will help.

I have several station towers grouped at 11 degrees on the map. I can get it to show 58 34 and 13 but cannot seem to find 6 to click on. That is a neat feature
 
 
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