Complex setup reception issues...Calling all cars!

dakjones · 24-Jan-2013, 5:54 PM

Hello all,

Here is my TVFool http://www.tvfool.com/?option=com_wr...1ddae3fe955096

My eyes are beginning to bleed from all of the reading that I have been doing. I have been on the roof and in my craw space everyday for a week and a half trying to figure this out. I've gone through 3 antennas (currently using 2 of the 3 with a UHF/VHF combiner) Here is what I have.

As you can see from the tvfool report, im not too far away from the transmitters but I'm guessing that its just a problem area? My house is in a bit of a valley and my antennas are pointed at a hill in the direction of the desired channel sources. They are roof mounted on a 15ft mast. The CS5 and the DB8 are separated by about 4 ft on the mast.

I've got an Antennas Direct DB8 for UHF and a clear steam 5 for VHF. The CS5 included a VHF/UHF combiner that I'm using with RG6 going straight into the house (apx 100ft maybe less) to a $66 high gain Radio Shack pre-amp, of course running through the mast mounted pre-amp component. The pre-amp is 1 in and 2 out setting in the living room right beside my home theater. One of those "out leads" is a 3ft RG6 line going to an HDhomerun dual network tuner (HDHR) which is wired to my whole home cat 6 LAN network. The second "line out" on the pre-amp is running back under the house to another TV in the bedroom (about 50ft). This run splits off about half way into my office to my HTPC. This feeds a PCI on-board tuner. So that's 1 split on the pre-amp and one split into the office.

My goal here is to get ABC, NBC, CBS & Fox and use Windows media center as my DVR and XBOX 360's as extenders. Now that you know my setup, here is the issues.

NBC is a constant, ABC is super direction-ally sensitive, CBS comes in but with poor signal quality and has never been stable and FOX shows up every now and then but has never been stable. If I get the antennas point just right and tweak the pre-amp I can get all 4 at the same time but with no real consistency and only do i see this if running straight to my Samsung's built-in tuner. The HDhomerun seems to be not near as sensitive as the TV's built-in tuner. I can switch from the TV's tuner to the HDHR and the results cut in half.

Here is my troubleshooting path so far:

1: Only a few days ago did I learn about pre-amp overload. The Radio Crap pre-amp has a booster switch and a gain dial. I have tested virtually every possible setting on this device (booster on, booster off and the gain dial in just about every possible position in both scenarios). The best results are as mentioned above. My gut is telling me that this pre-amp is the problem. Logic is telling me that my current results are the best that it can be (i sure hope not). Here is more info on the pre-amp if it helps http://www.radioshack.com/product/in...9&locale=en_US

1: I tried eliminating the pre-amp all together which cut me down to almost nothing. RG6 run is just too long i guess.

4:Tried using only one antenna (tried both). Direct run from single antenna to the amp, from the amp to the TV and or the HDHR.

5: Raised the mast from about 6ft to 15ft (i havent moved the antenna to different locations on the roof yet because I'm using an old dish mast as my base. I guess i'll try that next.

I am running out of ideas. Is this pre-amp crap and I need another one?
Is this as good as it gets?
What am I missing?
Please help me

GroundUrMast · 24-Jan-2013, 7:03 PM

I'm not worried about overloading the preamp with the TV signal levels shown on your report. I suspect that the Radio Shack amplifier is noisy... notice how RS does not advertise the noise figure for the product: http://www.radioshack.com/product/in...tent=CT2032189 The Antennas Direct PA-18 has a very low NF (less than 2 dB) and enough gain to drive the cable and splitters you're describing.

But, reliable reception starts at the antenna... The DB8 is a viable option, that you're not seeing much UHF reliably suggests to me that you need to go higher and/or switch to an even higher gain antenna such as the Antennas Direct 91XG or Winegard HD9095P. For VHF, I would also make a similar recommendation, higher and/or lager. An Antennacraft Y10713 or Winegard YA1713 comes to mind. You're facing 'deep fringe' conditions that call for the largest antennas and a low noise amplifier.

I have several HDHR tuners, they are not the least sensitive tuners in the house, but they're not the most sensitive either. I would be curious to know what your HDHR tuner sees when connected directly to one antenna, with no preamp, just a short coax, an extension cord for power and a long CAT-5 cable (for testing purposes... the HDHR would be outside, just below the antenna.)

The bottom line is this, until you have a reliable signal at the antenna, no amplifier will be able to help you. Amplifiers can't create a reliable signal if the antenna is not receiving one. Amplifiers are only able to 'push' signal through cable and splitter losses, they can not 'pull' signal from an antenna or out of the air.

GroundUrMast · 24-Jan-2013, 7:26 PM

You may want to check your FM Fool report for strong FM signals. If you have any high powered FM stations nearby, you'll want to consider using an FM trap.

dakjones · 24-Jan-2013, 7:42 PM

Quote:

Originally Posted by GroundUrMast

I'm not worried about overloading the preamp with the TV signal levels shown on your report. I suspect that the Radio Shack amplifier is noisy... notice how RS does not advertise the noise figure for the product: http://www.radioshack.com/product/in...tent=CT2032189 The Antennas Direct PA-18 has a very low NF (less than 2 dB) and enough gain to drive the cable and splitters you're describing.

But, reliable reception starts at the antenna... The DB8 is a viable option, that you're not seeing much UHF reliably suggests to me that you need to go higher and/or switch to an even higher gain antenna such as the Antennas Direct 91XG or Winegard HD9095P. For VHF, I would also make a similar recommendation, higher and/or lager. An Antennacraft Y10713 or Winegard YA1713 comes to mind. You're facing 'deep fringe' conditions that call for the largest antennas and a low noise amplifier.

I have several HDHR tuners, they are not the least sensitive tuners in the house, but they're not the most sensitive either. I would be curious to know what your HDHR tuner sees when connected directly to one antenna, with no preamp, just a short coax, an extension cord for power and a long CAT-5 cable (for testing purposes... the HDHR would be outside, just below the antenna.)

The bottom line is this, until you have a reliable signal at the antenna, no amplifier will be able to help you. Amplifiers can't create a reliable signal if the antenna is not receiving one. Amplifiers are only able to 'push' signal through cable and splitter losses, they can not 'pull' signal from an antenna or out of the air.

Thanks for the reply, This is the kind of help I need. I will see if I have the extra cable that I need to test plugging in the HDHR in near the antenna for testing purposes. I'm not sure if I can get away with purchasing another antenna. My wife is about to kill me over the cost of this project. Do you think switching to the P-18 pre-amp might help? I guess testing the HDHR near the antenna would shed some light.

What about this.... during this project i discovered that my wifi signal is pretty strong on the roof. I read that a HDHR can be discovered on the network when plugged directly into a NIC (network interface card). So do you think I could get my laptop on the roof, an extension cord for power to the HDHR and a short CAT 6 cable to plug it into the laptop. Would that work?

GroundUrMast · 24-Jan-2013, 9:37 PM

Yes, the HDHR will try to obtain an IP address via DHCP (from your router usually), if that fails it will default to a 'net-local' IP address. If the wired NIC on your laptop is configured to do the same, the two devises will be able to communicate. This method takes some additional time to start working initially because the DHCP process has to timeout fist. You don't need a WiFi signal for this to work.

Just remember, the only thing between the antenna and HDHR should be a short (10' or less) coax cable. You want to have as little loss from the antenna to the HDHR. The same will be true for the preamp when you get to the point of reinstalling or replacing it.

I'm certain the PA-18 will outperform any RS amplifier. But, think of a well as an analogy to the antenna... would you expect to get clean water from the tap if you installed a high quality, high pressure pump in a hole that had just a bit of muddy goop at the bottom? Obviously, the hole is not an effective well unless it is deep enough to reach a steady supply of clean water. If RS will still accept the amplifier for refund, I would take them up on that... the $70 may be a valuable peace offering to your wife. the PA-18 is available through Amazon for about half the price of the RS product. http://www.amazon.com/Antennas-Direc...8+preamplifier

dakjones · 25-Jan-2013, 1:36 PM

Quote:

Originally Posted by GroundUrMast

Yes, the HDHR will try to obtain an IP address via DHCP (from your router usually), if that fails it will default to a 'net-local' IP address. If the wired NIC on your laptop is configured to do the same, the two devises will be able to communicate. This method takes some additional time to start working initially because the DHCP process has to timeout fist. You don't need a WiFi signal for this to work.

Just remember, the only thing between the antenna and HDHR should be a short (10' or less) coax cable. You want to have as little loss from the antenna to the HDHR. The same will be true for the preamp when you get to the point of reinstalling or replacing it.

I'm certain the PA-18 will outperform any RS amplifier. But, think of a well as an analogy to the antenna... would you expect to get clean water from the tap if you installed a high quality, high pressure pump in a hole that had just a bit of muddy goop at the bottom? Obviously, the hole is not an effective well unless it is deep enough to reach a steady supply of clean water. If RS will still accept the amplifier for refund, I would take them up on that... the $70 may be a valuable peace offering to your wife. the PA-18 is available through Amazon for about half the price of the RS product. http://www.amazon.com/Antennas-Direc...8+preamplifier

That's an interesting way think about it and makes sense.

So I ran an extension cord to the roof for the HDHR, and once again climbed up on the roof armed with my trusty laptop in 20 degree weather. I tested first with a direct run from the UHF/VHF combiner for which of course has short coax runs to both the CS5 and the DB8 antennas eliminating the pre-amp.

The results were puzzling. I ran the scan with the HDHR's config application and it returned only 9 channels where it had been getting anywhere from 14 to 16 channels when using the pre-amp and running through 100ft of coax. The results where the same when I ran straight from the DB8 to the HDHR (I thought this would eliminate any issues with the UHF/VHF combiner). Same results. It didn't make sense at all.

All that said, I did find a problem area. The Radio Shack pre-amp included a short coax cable for the mast mounted portion which I used. I found that it was RG59 and not RG6!! I replaced it with RG6 and wow did that make a difference. At this point I had installed the HDHR in the house and didn't get a chance before dark to bring it back onto the roof to test with the new cable installed. Installed in the house the scan returned 18 channels including all the major network (I've never seen results this good). CBS was not stable but everything else was. CBS is my only VHF channel and probably the most important because they do not have a deal with HULU.

I'm thinking now maybe I can tweak the position of the CS5 to improve upon CBS and get the PA-18 pre-amp for noise reduction?

How does that sound?

Should I be worried about the 2 1/2 star review on the PA-18?

dakjones · 25-Jan-2013, 2:17 PM

Would this pre-amp be better?

http://www.amazon.com/Antennas-Direc...9+preamplifier

ADTech · 25-Jan-2013, 3:29 PM

You're in a 200-300' deep topographical hole less than a 1/4 mile from the valley walls. At best, reception is going to be hit or miss due to the severe shadowing from the northeast in particular. Most likely, the signals simply aren't there unless you happen to get a reflection from the opposite side of the valley.

Go ahead and try a pre-amp, there's no risk of signal overload.

Estimated location:

26-Jan-2013, 3:16 AM

To see what signal strengths are at other antenna heights please make and post 4 more tvfool radar plot reports at.

1 foot antenna height.

10 feet antenna height.

40 feet antenna height.

60 feet antenna height.

So I can recommend a antenna and antenna system that is correct for the reception.

GroundUrMast · 26-Jan-2013, 5:56 PM

The low rating on Amazon needs to be interpreted... by filtering out all the reviews made by people who had no idea of what the amplifier was for, and therefor 'put a high quality pump at the bottom of a muddy hole' or, applied it incorrectly.

The more knowledge and experience required to apply a product effectively, the lower the average review score will be, due to the skewing by ignorant reviewers blaming the product for their ignorance.

The CPA-19 is a very good option, with almost as good noise performance as the PA-18. In your application, they are interchangeable. I would not suggest the PA-18 if there were strong signals present.

Tower Guy · 27-Jan-2013, 2:05 PM

Quote:

Originally Posted by dakjones

CBS was not stable but everything else was. CBS is my only VHF channel and probably the most important because they do not

I'd consider the problem is multipath. You could try a more directional VHF antenna such as the Y10-7-13.

dakjones · 29-Jan-2013, 2:18 PM

Thank you all for your help. I'm sorry for the late reply. I've been traveling for work the past few days.

I don't really have the option of trying another antenna right now and already have a 15ft mast which is as tall as I'm going to go. I have ordered a antennas direct CPA 19 pre-amp http://www.amazon.com/Antennas-Direc...9+preamplifier

It should arrive today and I will report back with the results.