OTA in rural KY... again

[dustyz]

I posted several years ago and got some great advice. I'm moving, and the new location is a little more rural, if that is possible, and I think the reception will be worse. ADVICE NEEDED! :-)

http://www.tvfool.com/?option=com_wr...513485fc4f0993

I'm building a 38-40ft tilt-down mast for my antenna, and have about 100ft of new underground rated RG6 cable running to it. I'd like to pick up these channels, if possible:

WDRB
WAVE
WLKY
WHAS or WBKO

I don't get WHAS or WBKO now, with my DB4e & pre-amp on the roof, but that was expected being in the VHF range. If I'm buying new, I'd like to pick it up. I'll need a new pre-amp too, and have the Winegard LNA-200 Boost XT in my amazon cart as we speak.

Most of those channels are at 43 degrees, so they are aligned. I know I have stronger signals in other directions, but these are the most used/needed.

Thanks in advance.

[rabbit73]

Hi, dustyz:

Yeah, the signals will be weaker at your new location. Your new mast will come in handy because you will need to do a lot of testing.

Try the DB4e and a preamp at the new location. You can add a VHF-High antenna using a UVSJ, and aim it at WBKO. An alternative would be to use a VHF-High/UHF combo antenna aimed at WHAS.

If the DB4e doesn't have enough gain for your new location, consider the DB8e with both panels aimed in the same direction.

The separate VHF-High antennas currently available are the MCM 30-2475 and 30-2476. They are inexpensive, have poor instructions, but seem to do OK.
http://www.mcmelectronics.com/produc...-2475-/30-2475
http://www.mcmelectronics.com/produc...-2476-/30-2476

The LNA 200 has been redesigned to meet the price point of the big box stores. My impression is that it isn't as good as when it first came out. My major concern is that it is powered by 5 volts, and there might be too much voltage dtop in a 100 ft run of coax. RG6 with a solid copper center conductor would have less voltage drop than RG6 with a copper coated steel center conductor.
http://www.avsforum.com/forum/25-hdt...l#post41430993

What preamp are you using now?

[dustyz]

I'm currently using this preamp:
http://www.amazon.com/gp/product/B00...rch_detailpage

It works well enough at the current location, but I plan to leave it with the house.

Do you think the DB8e would work at the new location? I don't plan to take the DB4e with me, so I will be buying new regardless.

Thanks for the advice.

[rabbit73]

The DB8e should be OK. It has more gain if both panels are aimed in the same direction. It has a more narrow horizontal beamwidth, but that shouldn't matter if all UHF channels are in the same direction.

[dustyz]

Hey rabbit. A quick update. I went with the db8e and pointed in the correct direction to get the channels we want. Strangely, and like you predicted, the Winegard Boost preamp has some issues with the 100ft run, maybe.

I ended up putting the antenna on a tilt pole that's about 23ft tall. Thats about 7 or so feet above my metal garage. I have another 20ft ready to add if needed. When lowered on the ground with the db8e sideways and completely off focus, the signal is ok on about 5 channels. When I stand it up, all signal disappears. I mean gone too... Not just weak. The signal is only a few points stronger with the antenna connected to the HDHomerun than without it.

I plan to test without the preamp tomorrow, hoping things are just over saturated... And not a metal building interference issue. You'd think the latter would be an issue with it lowered as well tho.

Ideas?

[Billiam]

If you are going to run 100 feet of cable you might want to invest in a good RG11 cable. Will have lower loss. Even a half db to a db on some channels will make all the difference between reliable reception on most days vs. an unwatchable signal on most days. I found that out a few years ago when I replaced a 75 foot run of RG6 with RG11. Made the difference on one UHF signal.

[dustyz]

Thanks Bill. That's a good idea. It turned out to be a longer run than I originally thought, so I'm probably closer to 150ft, unfortunately.

There was a pinch in the coax, near the hinge of the tilt pole, that caused the signal loss. I fixed that & picked up a good 19 channels at about 75ft on the coax run. The signal is fairly strong on those that were picked up, at around 70-75% on the HDHomerun. But, by the time I run the remaining 75ft, the signal is gone, or too weak to pick up.

So, I'm trying to figure out a way to maximize signal strength. I have one splice in the first 75ft section that I could remove. I could replace the first 75ft with RG11, as you recommended too. I could push the antenna up another 17ft too. My pre-amp is fine, I think.

I'm running numbers now. It looks like RG6 has a 5.60db loss over 75ft (using a 600Mhz base frequency), while the RG11 would be somewhere around 3.55db. Is that correct? That's a substantial 2db gain over 75ft. I can't replace the full 150ft... the last 75 of RG6 was installed below grade in conduit. Correction. I could probably replace that other 75 too, since it is in conduit. I could probably pull it through easier. (That's an idea. 200ft of RG11 is $100 on Amazon. I'll check on connectors too, because I'll need those)

Now, I only put my mast @ 23ft now, but have enough area/material to add another 17ft if needed. So, here is my report for 23ft: http://www.tvfool.com/?option=com_wr...51344e0b85d224

As of now, I'm clearly picking up the following channels @ the 75ft coax mark:

WTVW - 7.1 - 9.4db
WBKO - 13.1 - 4.7db
WDRB - 41.1 - 1.5db
WMYO - 58.1 - 1.3db
WLKY - 32.1 - -1.5db
WHAS - 11.1 - -2.1db
WKZT - 23.1 - -7.5db
WBKI - 34.1 - -15.2db (How the hell?)

Here is the report for 40ft: http://www.tvfool.com/?option=com_wr...513497ea72eb52

WTVW - 7.1 - 11.1db (+1.7db)
WBKO - 13.1 - 7.3db (+2.9db)
WDRB - 41.1 - 6.8db (+5.3db)
WMYO - 58.1 - 6.6db (+5.3db)
WLKY - 32.1 - 3.6db (+5.1db)
WHAS - 11.1 - 1.8db (+3.9db)
WKZT - 23.1 - -1.7db (+5.8db)
WBKI - 34.1 - -15.2db (+1.5db)

Major gains with the increased elevation. Those gains alone could potential offset any coax loss, right? If I replace the first 75ft of coax with RG11, gaining 2db across the board, then bump the antenna up 15-17ft, I'll see 3-8db gains on all the important channels.

Is that the direction I should head first? Thanks for the advice!

[dustyz]

Yep, that's the plan. I'm replacing the last 75ft with RG11, through the conduit. The rest is above grade, so I can replace it any time easily. That should give me a few db's. Then, I'm raising the antenna another 10ft on the pole. I could go higher, but aesthetically, I'd rather not unless I absolutely need to. I'll go ahead and add the full 17ft pole, but move the antenna up 10. I can remove the 7ft at any time if the signal quality is good, or move the antenna up if forced.

So, based on my calculations & this link, I should see these gains(lack of loss?) with the RG11:

200Mhz? band RG11 increases = 0.79db
WHAS - 11 - -2.1db
WBKO - 13 - 4.7db
WBKI - 19 - -15.2db

500Mhz band RG11 increases = 1.24db
WTVW - 28 - 9.4db
WLKY - 26 - -1.5db

600Mhz band RG11 increases = 1.37db
WKZT - 43 - -7.5db
WDRB - 49 - 1.5db
WMYO - 51 - 1.3db

Bumping the antenna up another 10ft should show gains of:

WHAS - 11 - -2.1db +3.2db
WBKO - 13 - 4.7db +1.5db
WBKI - 19 - -15.2db +1.0db
WTVW - 28 - 9.4db +0.8db
WLKY - 26 - -1.5db +0.4db
WKZT - 43 - -7.5db +3.2db
WDRB - 49 - 1.5db +3.5db
WMYO - 51 - 1.3db +3.4db

I have one unnecessary splice in the RG6 up the antenna, due to the crimping issue, that I could remove. That should pick up between 0.2db-1.0db from what I've read.

Every little bit will help.

[Billiam]

Dustyz. Calculations you provided are probably right. I used an online tool to calculate that stuff back when I was looking at using RG11. At my current home which is just south of Cincinnati, the signals are so strong that I don't need it. Even get four Dayton stations with a little 4 bay (U4000 from Antennacraft) and the RCA pre amp.

BTW. Replacing the RCA with a higher gain pre amp may also help. The RCA is a good amp and ideally suited in areas with some stronger signals nearby. But there are other pre amps which offer better gain and a lower noise floor that should help if you are in a real fringe or deep fringe area.

Replacing the entire run of RG6 with RF11 is the best move. You will lose some signal if you have to do a splice or use a connector of some type.

[dustyz]

Originally Posted by Billiam

Replacing the RCA with a higher gain pre amp may also help. The RCA is a good amp and ideally suited in areas with some stronger signals nearby. But there are other pre amps which offer better gain and a lower noise floor that should help if you are in a real fringe or deep fringe area.

I think you are correct, the pre-amp is underpowered. (I'm using a Winegard Boost XT at the moment, however.)

Over the weekend I raised the antenna to 33ft & replaced 100ft of RG6 with RG11. So, now I have 100ft of RG11, with 3/4 of it underground + 50ft of RG6, down the antenna pole & over to the RG11... and an inline surge connector in the middle, working as a splice. No other splitters or junctions in the line, and 150ft total coax.

I can pick up a few channels on the Tivo, but they are in and out... nothing reliable. That's more than I've been able to get up to this point, so that's a good thing.

It just bothers me because I can put the HDHomerun inline between the two cables, and the signal strength is ok @ 70-75 on several channels. Decent quality too.

But, like you (and rabbit) said above, I think the pre-amp might be the problem now. It's one of those USB powered pre-amps, so I might need to spend a little more on a higher gain/voltage setup.

Recommendations? Or, do you think that's the problem? (I will likely start with the pre-amp, then swap out the remaining RG6 if that doesn't help.)

EDIT:
Here's a thought too. The underground portion of the RG11 is in a 2" conduit with 4 other wires. Two of those wires are for my PoE network, while the other two are for my alarm system. Do you think the coax is picking up a lot of noise from those?

[dustyz]

I found this link, and it's very educational for those who don't understand the basics, like me. :-)
http://www.hdtvprimer.com/antennas/basics.html

That page basically says I need a low noise pre-amp with enough gain to cover the signal loss over the coax, and another 10db to keep the Tivo receiver out of the picture. It goes on to say I could boost it another 10db without causing problems @ the receiver.

So, I could in theory, use a pre-amp with a 25+ gain. Wow.

What about one of the Channel Master 7777 pre-amps? Recommended? They have a higher 15V voltage that could transcend the coax without too much drop, and enough gain to compensate for signal loss. Low noise too, at under 2db.

[Billiam]

Kitztech makes a low noise, high gain pre amp. I tried one and it works but I had too many strong signals nearby to make it effective. That is why I use the RCA unit. If I end up moving to a rural area again I would buy the Kitztech.

[dustyz]

Interesting. I've never heard of that company.

Which model did you have? It looks like the KT-200 would work well for me. I don't like the lack of weather protection on the amp.

Thanks for the help.

EDIT:
I emailed Kitztech, and he recommended the KT-500 because of the distance from stations & cable run. $110... that's an expensive investment. :-|

[Billiam]

Yeah, I tried the KT-500. I agree with that assessment. You can return it for a refund if it doesn't work for you. I returned mine since I had too much signal overload where I as using it.

[rabbit73]

I favor the Channel Master 7777 for you. It is easily overloaded, but I don't see any very strong signals in your report that would do that.

I also did an FM signal report using your short coordinates. I don't see any FM signals strong enough to interfere with TV reception, and the 7777 has an FM filter.
http://www.fmfool.com/modeling/tmp/0...e/Radar-FM.png

The Kitztech and Research Comm preamps are in a special class with ultra low Noise Figures to receive weaker signals, but they are more sensitive to static damage; that's the trade-off. Both manufacturers have added protective devices to reduce possible static damage.

If you go with Kitztech, the reports say go with the 200 for a low NF. Calaveras at AVS has done extensive testing of preamps for NF and SFDR. Spurious Free Dynamic Range defines the ability to receive weak signals when you also have strong signals that might interfere.

PREAMP COMPARISON CHART IN ATTACHMENT.

[ADTech]

I would skip the KT500 completely. I can't, for the life of me, justify its existence based on my testing of it.

The KT200, when I tested it for gain and noise figure five years ago, tested well. I didn't have overload testing ability at that time, so I've not investigated that aspect of it.

If in doubt, stick with one of the medium gain pre-amps, they will, at least, keep4you out of overload trouble. You can always add a distribution amp down the line if necessary.

[dustyz]

Originally Posted by rabbit73

I favor the Channel Master 7777 for you.

Thanks. The reviews I read for the Kitztech series were usually compared to the 7777... which is encouraging. It's $50 cheaper too.

[rabbit73]

ADTech's conservative advice is also valid. The lower gain preamps, like the CM7778 and the AD Juice, have sufficient gain to cover distribution losses. Once the signals are amplified by the preamp, they are better protected from distribution losses. A 3 dB loss between the antenna and the preamp input can be 10x worse than a 3 dB loss after the preamp. So, keep the coax between the antenna and the preamp input short, because that loss directly subtracts from the antenna gain and increases the System Noise Figure. Here is an example of how much difference the placement of a 3 dB loss can make:







The preamp Noise Figure is important because it primarily determines the System Noise figure because of its location at the head end, according to the Friis Noise Figure equation; the lower the figure, the better able you are to receive weak signals.
https://en.wikipedia.org/wiki/Friis_formulas_for_noise

You can do your own calculations for your system using the Systm Noise Figure Calculator by holl_ands and majortom:
http://imageevent.com/holl_ands/files/ota

http://imageevent.com/holl_ands/file...=0&w=1&s=0&z=4

[Billiam]

The Kitztech has a lower noise floor than the CM. I also own the 7777 and it is a good pre amp. But it does have a higher noise floor.

[dustyz]

Thanks for the help everyone, and useful charts, rabbit. I ended up going with the 7777, and will take the chance of overload. There are just too many good reviews out there for the 7777.

I spoke with Winegard, and they said the LNA-200 wasn't recommended for cable lengths over 100ft, and "it will result in signal loss." I'm really hoping that's the issue. I know the signals come in clearly halfway down the line, then fall off too much after the full 150ft. It does make sense.

We'll see. TBD