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Thank you majortom and Jase88. I replied in the TVFool forum this morning and nearly forgot to check this thread. As far as the Vhf-Hi antenna is concerned, I don't really know the make and model of it. I salvaged it and repaired it. If I remember correctly, it's a 9 or 10 element yagi. Ion on real channel 12 is coming in, as well as WHTM on real channel 10. I really do think that TVFool may be off on real channel 8 because a single antenna will pick it up (either 8-bay or yagi) by itself no matter which way it's aimed. If it wasn't for WGCB on real channel 30 (49.1,49.2,49.3,49.4) coming in at an odd angle (almost 90 degrees to the left of of the Harrisburg stations), I'd probably just not use the 8-bay at all. I'm thinking that both antennas are grabbing real channel 8 and the signals are interfering with each other. So, my first plan is to use only the Uhf side of a UVSJ (and terminating the Vhf side) on the 8-bay before the preamp to try and further filter out any Vhf-hi signals. Also, to test my theory, I'm going to try unplugging one of the antennas to see if they actually are interfering with each other. I won't be able to try anything until Sunday as it's a 2-hour drive from my house to her's. Rabbit73 ran a FMFool report for me and didn't see any strong FM stations that would interfere. It's been a bit of a puzzle, but I think that's why I enjoy this. Again, thank you for all the help. You guys are awesome.
 

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Success!

Alrighty then. First off, I must humbly admit that I was wrong about the antennas interfering with each other. Secondly, it turns out that while real channel 8 is a strong signal, it can still be blocked. While I don't understand why I could pick it up everywhere around her house and in every direction, it turns out that my final mounting spot needed some adjustments by first cutting a single branch that was about 10 feet directly in front of the yagi, and secondly, for whatever the reason at this spot, I actually had to aim the thing whereas before, it wasn't necessary. I tried each antenna individually first and when that didn't work, I plugged the 8-bay into the VHF port, which also didn't work. That's when I noticed the branch and cut it. Channel 8 came back in pixelated (it wasn't even doing that when I got there). I aimed it about 10-15 towards the direction of the transmitter and it cleared up perfectly. So, problem solved. And in my haste to hurry before the thunderstorm rolled in, I over tightened the balun and broke it, losing all Vhf-Hi channels. Of course, I didn't have a spare, so I stripped the coax and put the ground braid to one side and the center conductor to the other and it worked (I think I saw this in one of the other threads). Not the greatest solution, but it should hold until I can get back down there to put another balun on it. Can someone tell me why this worked and if that's the case, why use one at all? I basically just copied and pasted this from the TVFool forum so I didn't have to retype everything.
 

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Why use a balun

Thanks for the update. It is hard for us to make a diagnosis of a reception problem when we aren't there with you, so we really appreciate the feedback.

So, it's the TREES! We know about TREES, they kill TV signals.
Not the greatest solution, but it should hold until I can get back down there to put another balun on it.
If you removed the connector, water can get into the open end of the coax. You might have to replace that length of water-damaged coax.
Can someone tell me why this worked and if that's the case, why use one at all?
The term balun is short for BALanced-to-UNalanced. The 300 ohm side is balanced because neither wire is grounded; the 75 ohm side is unbalanced because the coax shield is grounded.

Your quick fix worked because there was enough signal for reception even though the connection wasn't optimum. The benefits of using the balun are:

1. The balun permits an efficient transfer of energy at the ratio of 4:1 to minimize losses. Some baluns are more efficient than others.

2. The balun prevents the pickup of interference on the coax shield at the antenna end of the coax. It is possible to have three currents flowing through the coax: the outside of the center conductor (good), the inside of the shield (good), and the outside of the shield (bad). The grounding block prevents the pickup of interference at the other end of the coax.

3. The balun keeps the SWR low on the coax to the TV. The goal is to have the SWR 1:1 on the coax to minimize losses. Without the balun, the SWR would be 4:1. The coax itself has a loss (attenuation factor) even at 1:1 that is frequency dependent; about 6 dB/100 feet for UHF. However, when the SWR is greater than 1:1. there is an ADDITIONAL mismatch loss.

http://www.k6mhe.com/files/Reflect_rev1.pdf
page 5, fig 1

http://www.arrl.org/files/file/Technology/tis/info/pdf/q1106037.pdf
page 1, fig 1

Forum member holl_ands states that it is desirable to design an antenna for DTV with a SWR less than 2.7:1, to not only minimize losses but to minimize the reduction of signal quality as defined by EVM based on the work by Dr. Bendov et al. I understand the additional loss caused by the mismatch, but I have yet to prove to myself the reduction of signal quality.
 

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To be honest, with the massive amount of trees in her area, it is a wonder she can get anything at all. The links you provided will grant me some interesting reading, so thank you for those. I just hope I'm able to keep up with it intellectually. It's somewhat ironic that I found real channel 30 by accident when I missed her driveway and drove about a mile trying to find a place to turn around. That's when I noticed a residence with an original CM4228 facing 90 degrees to the left of where WHTM was coming from. Figured I'd face the 8-bay that direction and give it a go. Sometimes it pays to stare at random antennas while traveling, which I never used to do before picking up this hobby almost 2 years ago and building T.V. antennas and spending hours reading through the forums...so, umm, yeah....thanks guys. Oh, and my wife would thank you too, but it would only be sarcasm...lol.
 

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My wife tolerates my antenna experiments because she wanted a battery operated TV for use during a power failure. She also knows that if I'm doing antenna experiments, I'm not seeing another woman. She even bought me an expensive signal level meter to measure TV signals.
 

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Where I live, the unemployment rate is fairly high, and since learning about antenna building I've been doing them for friends and family who either can't get cable/satellite or can't afford it. To date, I've built two single-bay Gray-Hovermans, a double-bay GH (that I use for myself), and three McClapp vertically stacked 8-bays (though one is actually in my basement for repairs). I say this because at this point, I think my wife would like to strangle me with coax cable or beat me to death with a mast because I spend so much time talking about it.
 

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Your hobby is very constructive and of great benefit to family and friends; they are lucky to have you.
 
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I am splitting an OTA signal as follows:

Antenna AntennaCraft U-4000
|
2ft coax
|
Pre-amp - Winegard AP-8700
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about 40 ft of coax
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pre-amp power injector
|______________________
| |
2 way splitter 16V wall wart
|____________________________
| |
about 4 ft coax about 2 ft coax
| ________|_______
TV input | |
HDHR tuner 1 HDHR tuner 2

Problem I am having is I have one channel that is a low power station
of the 5 I can receive loses about 10% of its signal strength with the addition of the splitter That I put in recently to give the TV its on coax input.

There are occasional times when the signal will drop below a reasonable level for the HDHR tuners, and cause drop out in recording.

The remaining channels are all 90 - 100 % signal strength after the additional split.

I have a PCT distribution amp with 4 ports (+8db) That I am interested in using instead of the 2 splitters above, and would like to power the distribution amp with the same wall wart as used for the pre amp using a splitter on the power. They are both using the same voltage input.

Or, should I consider switching to an pre-amp such as the CM-7777 and forget about the distribution amp.

Thanks!
 

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jr3us,

only use one or the other amplifier, never more than one stage of amplification at a time.

Go to TV Fool, and run your tvfool report with accurate location information for your house. then paste the link to your tvfool report here so people can provide meaningful suggestions.
 

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Thanks, I will not use the distribution amp in addition to the pre amp.

Unfortunately, when TVfool updated their database, The Wilmington NC area is borked and has no information for the currently available channels where I am located. Prior to them updating, I did a 'screen scrape' and I will see if I can attach it to this.
 

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I agree. The solution in this case appears to be a higher gain preamp. I never had much luck with the Winegard AP-8700. Channel Master CM-7778 might be a better choice when high powered local stations are present but wouldn't offer any more gain. A Channel Master CM-7777 should be a better choice for weak stations.

It's not clear which HDHomerun tuners are being used. The HDHR3 had some issues with weaker stations and adjacent channel interference. The HDHR4 series is better.

A TVFool report would help.
 

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if tvfool doesn't work out, can get people close with the fcc's tool...
Just get it close with a nearby street and cross street maybe.
Then indicate which channels your having issues with.
also, is your antenna outside above the roofline or is it inside in an attic or sumthin?



https://www.fcc.gov/media/engineering/dtvmaps
 

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Well, this is odd. In the fcc.gov link, the station I am having the occasional problem with is WILM-LD broadcasting on real channel 15 and is not included in the stations available where I am. It is an independent station and not a member of any network, though 1.5 years ago, it was affiliated with CBS.

Here is the best source of 'technical' info i can find for this station:

https://rabbitears.info/market.php?request=station_search&callsign=167819
 

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I did a reply with a link to rabbitears.info and the channel WILM-LD. That was the closest I can get to technical info for them currently. My post with the link is queued for approval by the digital home admins.

My antenna is about 20 feet off the ground facing north east mounted outside on the north side of the house, where the stations are located for the Wilmington area.
 

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I'm ok with moving it to another part of the forum. I am in zip code 28469 which is inside the red circle on the contour map.
 

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In Tvfool, use your coordinates instead of the address.
It seems to work fine for me, picking a random lat/long in your Zip code.


To determine your lat/long go to google maps, plug in your exact address.
at the pushpin of your location, rt click on the pushpin, select "what's here".
Your Latitude / longitude will be there...
go to tvfool, check the coordinates radio button. enter your coordinates found from google maps. Enter your antenna height. click "Find Local Channels". Paste the resulting Link here so we can look at it. It will trim the last few decimals of your coordinates, so no one will see your exact location.
 

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That's a big zip code area



Can you be a little more specific so that we can give you accurate advice?

If you post your TVFool report link based on your exact address or coordinates, we can try to generate a more accurate report using another site. TVFool is using a database with many errors to generate reports. There are many channel changes because of the FCC Repack of UHF channels.
 
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