Attic mount.. most stations perfect.. preamp help?

[snooperloop]

Hola all!

I wanted to get some advice on some reception. Currently I have a Winegard HD7694P mounted in the attic... From there is a 35' Quadshield cable straight to single TV no splits or barrel connectors or anything. I am able to pick up every channel I want clearly except for 8pbs 11cbs 13abc

These stations DO however come in very hiccup free at night.. During the day these channels are not watchable. I have checked aim on antenna many times and it has come up with no better results.. Other stations great... 3 offenders working only at night.

I do have tech shield (yes yes I know bad move) but I would prefer to keep antenna off my home for many reason. The wife.. having to do a second ground rod and tie it to existing. Roof deck penetration. I just don't want to unless I have to.

So my lack of intelligence question is would a preamp help me at all even though i am not splitting off to more than one TV and I only have a 35 foot run from the antenna to the set? It seems that reception is just almosT there since it works at night

I have also included a pic of the TVFOOL analysis and a link as well

http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3df1f0bc689f6236

http://i.imgur.com/CYsxRS2.png

[ADTech]

The obvious solution is to get the antenna out of the attic.

Your signal power *should* be very strong, but Techshield will have an unmeasured amount of attenuation. Perhaps its only 10 dB on VHF, perhaps its 50+ dB. No one knows for sure.

VHF is HIGHLY susceptible to localized interference from a host of sources that may not be readily apparent. Among these are anything that is solar powered, FM radio stations, electrical and electronics, and power transformers/lines.

If you are indeed encountering some sort of generated interference, then an amplifier will only make it worse.

[snooperloop]

Understandable.... Garbage in means garbage out.. Or in this case AMPLIFIED GARBAGE OUT

I really did not want to move it outside but we cannot always have what we want.


The obvious solution is to get the antenna out of the attic.

Your signal power *should* be very strong, but Techshield will have an unmeasured amount of attenuation. Perhaps its only 10 dB on VHF, perhaps its 50+ dB. No one knows for sure.

VHF is HIGHLY susceptible to localized interference from a host of sources that may not be readily apparent. Among these are anything that is solar powered, FM radio stations, electrical and electronics, and power transformers/lines.

If you are indeed encountering some sort of generated interference, then an amplifier will only make it worse.

[No static at all]

Sounds like you just need a bit more gain to make those channlels watchable during the day. If in your shoes, I would try the RCA TVPRAMP1R from Walmart & see if it helps.

If it doesn't you can return it & try to convince the wife that the roof may be the only viable option to paying for cable.

[ADTech]

You don't need more gain, you need more of a cleaner signal. Amplifying a "dirty" signal gains you nother. With only 35' of coax, adding the RCA preamp would, at most, improve the system noise margin by about 3-5 dB (Assumptions: 1 dB coax IL @ 200 MHz, RCA NF=3.1 dB @ 200 MHz, Tuner NF=~4-7 dB). Since his calculations suggest an excess of 50 dB margin before building envelope attenuation and antenna gain, the odds that a pre-amp is going to fix this are near zero. Skip the amp, identify the source of the problem and fix it.

You probably need to look at the hints I offered to see if any apply. Your existing antenna has plenty of gain and it is unlikely that the Techshield is attenuating your VHF (only) by 50 dB. Therefore, noise of some kind is likely and, since the issue abates at night time, something solar would lead my list.

A simple dipole outside *should* suffice in the absence of RFI.

[Tower Guy]

Have you checked that the VHF dipole elements that are connected to the matching transformer are unfolded properly?

[ADTech]

Hmmm... Didn't consider an assembly error... Definitely something to check!

Might also be a bad coupler board. Call Winegard.

[Tower Guy]

Hmmm... Didn't consider an assembly error... Definitely something to check.

It's a mistake that I made ONCE.

[ADTech]

Yeah, I can probably figure out the wrong way to assemble almost anything...

[Jason l]

I have to favor the outside move. But yes to all of above as well. Amps are a must for me but only for my grey channels. It might help it might not. I would try it first if you want to keep it inside as well all above opinions.

[No static at all]

Yes, that's why I suggesed the amp, even though the OP really shouldn't need one.

We all know how some women & antenna's don't always see eye to eye. (they just don't believe in "line of sight"):D

[snooperloop]

Yes, that's why I suggesed the amp, even though the OP really shouldn't need one.

We all know how some women & antenna's don't always see eye to eye. (they just don't believe in "line of sight"):D


LOL They believe in line of sight as long as it is them giving you a dirty look..

I tried the preamp. Though it did not create any 'issues' but it did not improve the signal on my two suspect channels. "sigh" outside it is lol

[rabbit73]

I tried the preamp. Though it did not create any 'issues' but it did not improve the signal on my two suspect channels. "sigh" outside it is lol It was worth a try. Your tvfool report shows very strong signals, but they might be very weak in the attic because of the Techshield.

Is it possible to find a location in the attic for the antenna so that it doesn't have to aim through the aluminum foil of the Techshield?

Can you make a temporary set up of the antenna outside?

Can you set up your antenna inside and aim it west through a window, no metal screen or lowE glass as test?

It is possible there is some noise interference during the day that you don't have at night, like powerline noise or neon sign noise. VHF is more prone to that kind of noise than UHF. I have one VHF channel that is marginal like yours because of powerline noise.

There have been some problems with the Winegard phasing line wires and even some improper assembly of the antenna by the manufacturer, which would make the antenna a poor performer for your VHF channels.

Winegard HD769 design (phasing lines)
http://www.digitalhome.ca/forum/showthread.php?t=142786
I just checked my hd7694p and my elements were installed wrong as well. Evidently quality control is lacking.
http://www.digitalhome.ca/forum/showpost.php?p=1755169&postcount=29

http://www.winegard.com/kbase/uploads/proper_phasing.pdf

http://www.winegard.com/kbase/uploads/1450292.pdf

This is what your FM signals look like. They are not real strong, but an FM trap might help.

http://forum.tvfool.com/attachment.php?attachmentid=974&stc=1&d=1428020886

A separate more directional VHF antenna coupled with your 7694 just for UHF with a UVSJ might help. The idea is to use a VHF antenna that has more gain not just for the gain but for its increased directivity to improve the SNR of your VHF signals that are almost wiped out by noise from electrical interference.

Is there some electrical device in your home that could be causing interference during the day?

[No static at all]

Have you tried different areas of the attic? Our townhouse has aluminum siding, & I have found a great attic hot spot for VHF with a bit of experimentation.

I would try that first if your wife is really against going outside.

[tomfoolery]

That's a relatively small antenna. Have you considered mounting it on a J-pole on the outside? High up, they don't look nearly as big, by the way.

Neighbor across from me has the model house in the development, and has some type of foil behind the siding, which he warned me about. He had to position his two attic antennas to 'look' through the roofing, and they work just fine, but some location experimentation was needed. Mine similarly is aimed through the roof, though it's for convenience, as I don't have any metal foil in the walls.

Just another couple of data points.

Edit: I should mention that my attic install is far from ideal, but the signals are strong enough, and the antenna gain high enough with a narrow(ish) beam width, that it works well enough for me. But outside is better than inside, as a general rule.

[ADTech]

Have you eliminated the other possibilities suggested: Improper assembly or defective combiner?

You won't be having much fun moving the antenna, then finding out it still doesn't work due to one of those issues after all....