EDTV or HDTV?
We've just created a new HDTV Review website. This is not the usual mass market crap! We get straight to the point. We'll focus our unbiased reviews on topline HDTV products. The www.the-hdtv-review.com is a new website and we will be adding to it frequently.
Not sure which is the better format. EDTV or HDTV? We've added a new article to our site. EDTV vs. HDTV .
The AVS Forum is a great place to find answers to any HDTV question. Here's another interesting question and answer plucked from the AVS Forum.
Question; Can you combine signals from two antennas?
Say you have two stations, one to the north of you and one to the east. If you have two antennas (one facing each station), can you use a splitter/combiner to have the leads from both antennas go into your tuner, in order to get both signals without having to move your antenna?
Answer: Yep, you sure can.
If both antennas are the same, as in UHF or VHF or UHF/VHF combo, you'll need to get a Channel Master Joinantenna to block out the frequency on one of the antennas.
If both antennas are NOT the same, ie one is UHF the other is VHF, a simple 2-way splitter used in reverse will accomplish this.
It's all kinda a crapshoot! Most antennas will pick up signals from ALL directions (I'm not talking about so called "omnidirectional" antennas either). Obviously, the received signal strength from the direction the antenna is pointed should be the strongest by far. But, there is almost certainly a weak/faint signal received from the sides and even the back of where it is aimed. The problem hooking 2 antennas together is then to try and get the received signals perfectly in phase... which can be very, very difficult if not impossible (at least affordably). If you don't accomplish this, you will likely end up with ghosting when you watch TV.
I'll carry your example a little further. Suppose both your antennas are VHF. With one you are trying to receive channel 2 (aimed north), the other channel 3 (aimed east). Lets assume that you get a nice, strong signal from each of the antennas separately. The problem is, there will be a weak signal of channel 2 on the east antenna and likewise a weak signal of channel 3 on the north antenna. If you merely use a signal splitter/combiner, most likely the strong signals and weak signals won't be perfectly in sync. This will result in ghosting on both channels (at least in analog land). You've probably heard of a similar problem people have with only one antenna called multi-path. It's pretty much the same thing except instead of the weaker signal coming from another antenna it is picked up by the back or side of the same antenna after it bounces off of buildings/trees/etc.
Probably the best (at least cheapest) thing you can do is to go ahead and try to combine them both with a decent splitter/combiner. You might luck out and get acceptable results. You can verify if you are creating a problem by hooking up each antenna separately, check out the quality of the picture on each then try them together to see if it is degraded. If not, or if the change is acceptable to you then great. If not, you'll either need to use filters as taz291819 said or you could use only one antenna mounted on a rotator (that you'd have to use whenever switching channels). There are a couple of things you can do to try and improve the results of combining with the splitter. Install your antennas outside... this should maximize the difference between the weak and strong signals. Mount both antennas on the same mast... this will help minimize the reception timing between the signals (reduce the mis-match). If you do that, you'll need to space them out vertically at least half the longest wavelength you are trying to receive which is, I believe, equivalent to the longest element on a yagi antenna (someone PLEASE correct me on this if I'm remembering it wrong!). You could buy the most directional antennas you can afford that claim to minimize multipath interference. Finally, you can try playing around with the length of coax running between each antenna and the splitter to try and improve the signal meshing (good luck... this one is a real pain in the a**!).
Well, I guess that is about all I can think of off the top of my head to tell you. I should mention that I've gone through the same thing and finally got an antenna rotator. Also, this all applies to analog OTA reception. I'm not sure whether it would be the same for digital reception (digital tuners might be able to ignore the "ghosted" signal)..
Here's links to our other pages.
Flat panel monitor advantages of plasma TVs and LCD TVs
LCD TV ratings
best LCD TVs in the 26 inch screen size
best 42 inch plasma TVs
Panasonic TH-42PHD7UY
NEC-42XR3
Pioneer PDP-4340
Panasonic 50 inch plasma TV
Pioneer 50 inch plasma TV
FAQ for HDTV
A link exchnage page
Go to our other site for audio visual equipment reviews. Check out www.dvd-recorder-review.com This site keeps current reviews of popular selling DVD recorders.
Not sure which is the better format. EDTV or HDTV? We've added a new article to our site. EDTV vs. HDTV .
The AVS Forum is a great place to find answers to any HDTV question. Here's another interesting question and answer plucked from the AVS Forum.
Question; Can you combine signals from two antennas?
Say you have two stations, one to the north of you and one to the east. If you have two antennas (one facing each station), can you use a splitter/combiner to have the leads from both antennas go into your tuner, in order to get both signals without having to move your antenna?
Answer: Yep, you sure can.
If both antennas are the same, as in UHF or VHF or UHF/VHF combo, you'll need to get a Channel Master Joinantenna to block out the frequency on one of the antennas.
If both antennas are NOT the same, ie one is UHF the other is VHF, a simple 2-way splitter used in reverse will accomplish this.
It's all kinda a crapshoot! Most antennas will pick up signals from ALL directions (I'm not talking about so called "omnidirectional" antennas either). Obviously, the received signal strength from the direction the antenna is pointed should be the strongest by far. But, there is almost certainly a weak/faint signal received from the sides and even the back of where it is aimed. The problem hooking 2 antennas together is then to try and get the received signals perfectly in phase... which can be very, very difficult if not impossible (at least affordably). If you don't accomplish this, you will likely end up with ghosting when you watch TV.
I'll carry your example a little further. Suppose both your antennas are VHF. With one you are trying to receive channel 2 (aimed north), the other channel 3 (aimed east). Lets assume that you get a nice, strong signal from each of the antennas separately. The problem is, there will be a weak signal of channel 2 on the east antenna and likewise a weak signal of channel 3 on the north antenna. If you merely use a signal splitter/combiner, most likely the strong signals and weak signals won't be perfectly in sync. This will result in ghosting on both channels (at least in analog land). You've probably heard of a similar problem people have with only one antenna called multi-path. It's pretty much the same thing except instead of the weaker signal coming from another antenna it is picked up by the back or side of the same antenna after it bounces off of buildings/trees/etc.
Probably the best (at least cheapest) thing you can do is to go ahead and try to combine them both with a decent splitter/combiner. You might luck out and get acceptable results. You can verify if you are creating a problem by hooking up each antenna separately, check out the quality of the picture on each then try them together to see if it is degraded. If not, or if the change is acceptable to you then great. If not, you'll either need to use filters as taz291819 said or you could use only one antenna mounted on a rotator (that you'd have to use whenever switching channels). There are a couple of things you can do to try and improve the results of combining with the splitter. Install your antennas outside... this should maximize the difference between the weak and strong signals. Mount both antennas on the same mast... this will help minimize the reception timing between the signals (reduce the mis-match). If you do that, you'll need to space them out vertically at least half the longest wavelength you are trying to receive which is, I believe, equivalent to the longest element on a yagi antenna (someone PLEASE correct me on this if I'm remembering it wrong!). You could buy the most directional antennas you can afford that claim to minimize multipath interference. Finally, you can try playing around with the length of coax running between each antenna and the splitter to try and improve the signal meshing (good luck... this one is a real pain in the a**!).
Well, I guess that is about all I can think of off the top of my head to tell you. I should mention that I've gone through the same thing and finally got an antenna rotator. Also, this all applies to analog OTA reception. I'm not sure whether it would be the same for digital reception (digital tuners might be able to ignore the "ghosted" signal)..
Here's links to our other pages.
Flat panel monitor advantages of plasma TVs and LCD TVs
LCD TV ratings
best LCD TVs in the 26 inch screen size
best 42 inch plasma TVs
Panasonic TH-42PHD7UY
NEC-42XR3
Pioneer PDP-4340
Panasonic 50 inch plasma TV
Pioneer 50 inch plasma TV
FAQ for HDTV
A link exchnage page
Go to our other site for audio visual equipment reviews. Check out www.dvd-recorder-review.com This site keeps current reviews of popular selling DVD recorders.
posted by Rich at 12:11 PM
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