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Old 29-Apr-2011, 7:58 PM   #21
sdubb
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Okay before I start throwing all kinds of money at this, It seems like there really is no other way to test things out. Is that what everybody is doing? Buying an antenna trying it out and then if it doesnt work back to the drawing board.

Now if I understand this right, I can buy the XG-91 and the 10G221 and with this setup I "should" be able to get my missing channels? Can I still use my exisitng antenna since I am able to get all my VHF channels.

I would rather not have to purchase another antenna strictly for VHF (7-13)
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Old 29-Apr-2011, 8:04 PM   #22
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Okay before I start throwing all kinds of money at this, It seems like there really is no other way to test things out. Is that what everybody is doing? Buying an antenna trying it out and then if it doesnt work back to the drawing board.

Now if I understand this right, I can buy the XG-91 and the 10G221 and with this setup I "should" be able to get my missing channels? Can I still use my exisitng antenna since I am able to get all my VHF channels.

I would rather not have to purchase another antenna strictly for VHF (7-13)
You have already demonstrated that you are right on the edge of reception of KNXV (by adjusting aim point), that gives me quite a bit of confidence that you are going to be able get KNXV. The numbers indicate the signal from KPPX is also strong enough to receive with the gain offered by the XG-91. The consumer grade alternative to the XG-91 would be a virtually identical Winegard (as measured by gain). After that you would need to look into commercial antennas or a site-built rhombic array, (a serious hobbyist project).

There is nothing wrong with trying to reuse your existing antenna as a VHF only antenna. Simply connect it to the VHF input port on the 10G221.
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Old 22-May-2011, 3:58 PM   #23
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Well I got the XG-91 all setup and guess what I have channel 15 (Thanks Guys)

Now the real problem is that most of my channels are all sitting at about the same in signal strength (50-60) I would have thought they would have jumped a lot higher with this new high gain antenna. I still keep having a lot of breakup in my shows.

My VHF channels signal strength show in the 70-80 (they still break up also)

I have not bought the 10G221 so I am unsure what will happen when I get that. For now I have just been testing to see where my signals are at and comparing the strength of the two. I have been doing this by hooking one antenna up and recording the numbers and then switch to the other antenna and record the numbers.
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Old 22-May-2011, 4:27 PM   #24
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In addition to fine tuning the aim point, fine tuning the elevation of the antenna can have a measurable effect on signal strength and quality.

Unless the antenna and TV are right next to each other, you're going to need to consider the amplifier. The goal is to take that hard won signal from the antenna and deliver it to the tuner at a level above the noise generated inside the tuner(s).
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Old 24-May-2011, 7:14 PM   #25
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So the amplifier will only take the signal it has and boost it down the cable correct? The amplifier does not give the antenna any boost just the cable?

I was thinking that if this is the case... I could use a short RG6 connected to my antenna and my HDHR on the roof and see what my signal strength is using my laptop.

I guess I am curious what kind of gain I will receive with a very short cable.

I am only feeding the HDHR, no other TV's.
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Old 24-May-2011, 7:32 PM   #26
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Originally Posted by sdubb View Post
So the amplifier will only take the signal it has and boost it down the cable correct? The amplifier does not give the antenna any boost just the cable?

I was thinking that if this is the case... I could use a short RG6 connected to my antenna and my HDHR on the roof and see what my signal strength is using my laptop.

I guess I am curious what kind of gain I will receive with a very short cable.

I am only feeding the HDHR, no other TV's.
Generally, yes. Because I don't know the noise figure of the tuner in the HDHR, I have to say 'I don't know' whether a high quality (low noise) amplifier will buy you a few dB of real NF over-all. For example, if the NF of the tuner is 10 dB and the NF of the amp is 3 dB, you could improve matters by as much as 7 dB (theoretically).

Bottom line, you won't hurt anything to try the HDHR right at the antenna.

Amplifiers never remove noise or distortion...
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Old 24-May-2011, 7:33 PM   #27
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An amplifier only boosts whatever signal is coming off the antenna, less losses for connectors and the amplifier's noise figure (typically around 2 dB). It doesn't make the antenna any "stronger", per se, but it can be very beneficial in cases where weak signals are otherwise lost in the cabling, distribution system, and the TV tuner's noise figure (6-10 dB typ.).

Keep in mind that the integrated "signal meters" are rarely showing the signal power of the input signal. Generally, they are a proprietary combination, of signal power, AGC voltage, and signal decoding quality.
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Old 25-May-2011, 6:13 AM   #28
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Are you reporting the signal strength indicated by the HDHR Config (GUI) utility?

Is your VHF antenna combined with the XG-91? If so, how?

Have you optimized the point of aim, antenna tilt and experimented with elevation of the antenna? The XG-91 is very directional and you need to have put every reasonable effort into putting it on target.

You said earlier that you had not purchased an amplifier yet. For the money, Antennas Direct CPA-19 and PA-18 beats all but the very expensive special order preamps for noise figure. In this case the published numbers for the 10G221 are about 1 dB worse... not a lot, but if you have not spent money on an amp yet...

The CPA-19 has better tolerance to high input levels than the PA-18. I did not suggest either amplifier earlier, because neither has separate VHF and UHF inputs. Both AD amps are capable of UHF and VHF but will require an inexpensive external UVSJ.

Because you are 'on the edge' I would revise my preamp suggestion from the 10G221 and suggest the CPA-19. Yours may be a case were every dB of noise figure is going to count.

The down side is that you may need a separate amp for VHF signals. I would try 'amping' the UHF antenna alone. Joining the two antennas with the UVSJ UHF port on the output side of the preamp.


All of this after you have searched for the very best aim, nose tilt and antenna mounting elevation.
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Old 25-May-2011, 7:09 PM   #29
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Are you reporting the signal strength indicated by the HDHR Config (GUI) utility? Yes
Is your VHF antenna combined with the XG-91? If so, how? I dont have a proper way to combine them so I have just been disconnecting and reconnecting to see where I was sitting at. I tried to combine it with a splitter to see what would happen but that didnt work, it seemed to only be using my VHF/UHF antenna. Basically I lost channel 15 when I used the splitter.
Have you optimized the point of aim, antenna tilt and experimented with elevation of the antenna? Yes The XG-91 is very directional and you need to have put every reasonable effort into putting it on target.

You said earlier that you had not purchased an amplifier yet. For the money, Antennas Direct CPA-19 and PA-18 beats all but the very expensive special order preamps for noise figure. In this case the published numbers for the 10G221 are about 1 dB worse... not a lot, but if you have not spent money on an amp yet... I will look into it

The CPA-19 has better tolerance to high input levels than the PA-18. I did not suggest either amplifier earlier, because neither has separate VHF and UHF inputs. Both AD amps are capable of UHF and VHF but will require an inexpensive external UVSJ.

Because you are 'on the edge' I would revise my preamp suggestion from the 10G221 and suggest the CPA-19. Yours may be a case were every dB of noise figure is going to count.

The down side is that you may need a separate amp for VHF signals. I would try 'amping' the UHF antenna alone. Joining the two antennas with the UVSJ UHF port on the output side of the preamp. You lost me on this one... My VHF channels are 20-30 higher than any of my UHF

All of this after you have searched for the very best aim, nose tilt and antenna mounting elevation.[/QUOTE]
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Old 25-May-2011, 7:45 PM   #30
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You lost me on this one... My VHF channels are 20-30 higher than any of my UHF
Take a look at this drawing...

Here is an example of a UVSJ

If you have solid reception of all you VHF stations, don't spend money amplifying them. The loss through a UVSJ is less than that of a reversed splitter so you will likely not need to amplify the VHF side.

Because you are right on the edge with several UHF channels, I'm suggesting this arrangement as the means to maximize every bit of noise margin possible.
Attached Files
File Type: pdf Preamp on UHF - VHF barefoot - UVSJ.pdf (20.2 KB, 338 views)
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Old 25-May-2011, 9:24 PM   #31
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I totally forgot about the UVSJ until your most recent post. I google what they were before you posted that link. I was thinking that is exactly what I need and its not to expensive.

I understand your diagram. Luckily I can do what you have pictured since there are outlets on the roof. (not sure if they even work though)

I still am planning on using a short piece coming right off the XG91 to see what this "high gain" is doing for me. I am glad that it picked up 15 but thought I would have been able to get 51 with this new antenna.

Side note... how does the UVSJ work as far as knowing what to let thru on both sides?

Also kind of sad that I had to buy this nice new antenna for one channel (15)

The XG-91 did pick up channel 10 which is a VHF
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Old 25-May-2011, 9:41 PM   #32
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The UVSJ is a filter made of some combination of inductors and capacitors. The UHF port does not pass frequencies below channel 14 (470 MHz). Most UVSJ designs allow DC to just over 216 MHz (the upper end of channel 13) through the VHF port.

The losses are relatively low, about 0.5 to 1.0 dB for signals in the pass-bands. Frequencies outside the pass-bands are attenuated 20 or more dB.

As far as preamps go, the power is fed up the coax from inside the building. The amplifier should be located within a short coax jumper length of the antenna. It would be quite unusual to locate the power supply on the roof or outdoors, most are not rated for such installation.
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Old 25-May-2011, 10:22 PM   #33
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Originally Posted by sdubb View Post
Also kind of sad that I had to buy this nice new antenna for one channel (15)
How much elevation tweaking did you do? That has been the key for getting difficult channels in many situations for me. Just a few inches can make or break reception on UHF. I suggest raising/lowering the antenna in 3-4 inch increments. Re-test all channels each time as the tweaking may require a compromise to recieve everything.

How far is the antenna from the roof or any other metal objects?
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Old 25-May-2011, 10:38 PM   #34
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As far as preamps go, the power is fed up the coax from inside the building. The amplifier should be located within a short coax jumper length of the antenna. It would be quite unusual to locate the power supply on the roof or outdoors, most are not rated for such installation.
This might be the killer... There is only one line that enters the house, If I have to add a seperate line its going to be a very interesting run to get the cable where it need to go (same place as the other one) they have all been run thru the house.
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Old 25-May-2011, 10:45 PM   #35
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How much elevation tweaking did you do? That has been the key for getting difficult channels in many situations for me. Just a few inches can make or break reception on UHF. I suggest raising/lowering the antenna in 3-4 inch increments. Re-test all channels each time as the tweaking may require a compromise to recieve everything.

How far is the antenna from the roof or any other metal objects?
I did a little bit of tweaking as far as height is concerned. I started with the antenna at the back of the house on a pole about 12-13 feet. Then I decided that I needed to move it to the front of the house. Nothing really changed. I decided to mount a J-mount on top of a false wall on the roof which gave me about 8 more feet. So now my VHF/UHF antenna sits at about 21' in the air.

Like I stated the antenna is on the roof at about 8' above the actual roof. I dont see any metal objects any where close by, not even any power lines.

I can provide pics if you guys think that will help.
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Old 2-Aug-2011, 5:57 AM   #36
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BIG THANKS to Groundurmast! and other for the help. I finally bought the 10G221 and am finally able to get channel 51.1 51.2 51.3
The signal is in the mid 60's (Sharp Aquos meter) but its not breaking in and out. I am sure with some more tweaking I will be able to get it a little higher. I still need to do some fine tuning but I just had to throw it together after it came in the mail today.

Now I need to read up on "grounding my mast" no seriously I do.
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Old 2-Aug-2011, 7:16 AM   #37
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Thanks for the update, glad that you're seeing KPPX!
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Old 13-Sep-2011, 3:42 AM   #38
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This is getting ridiculous!!! I had everything dialed in 2 weeks ago, All my channels were working and even recorded a show on 15.1 fast forward to now 15.1 is basically gone I have no signal strength and when I do get it, it pops in and out and is only stable for about 5 seconds. Nothing has changed on my roof its all bolted down and locked down.

Anybody have any other ideas before I pitch all this equipment off my roof
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Old 13-Sep-2011, 4:55 AM   #39
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This is getting ridiculous!!! I had everything dialed in 2 weeks ago, All my channels were working and even recorded a show on 15.1 fast forward to now 15.1 is basically gone I have no signal strength and when I do get it, it pops in and out and is only stable for about 5 seconds. Nothing has changed on my roof its all bolted down and locked down.

Anybody have any other ideas before I pitch all this equipment off my roof

Any noticeable change in the weather?
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Old 13-Sep-2011, 5:00 AM   #40
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yes... rain and dust storms
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