AVS Forum banner

Osceola, IA: Antenna Recommendations

2K views 23 replies 8 participants last post by  ctdish 
#1 · (Edited)
We're consider dropping Directv and switching back to OTA, I'm looking for antenna recommendations, living out in the country the antenna's exposed to some pretty severe winds and everything we've had in the past has fallen apart. I ran across this one http://www.amazon.com/Lava-HD-2605-Antenna-Remote-Control/dp/B002MW0K22/ref=cm_cd_ql_qh_dp_t and it seems much smaller than most I've seen so less likely to break.

I understand the stations broadcasting in VHF and our distance are severely limiting our options to the larger antennas but there's not much we can do about that :(

http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id=e1c6d7fc5d87dd
 
#3 ·
Most here will say Lava's are junk and I tend to agree, but on the other hand I use one that I got about a year ago and it survived the brutal New England winter we had this year that included, ice, sleet, snow & strong winds...maybe I got lucky. Only reason I used one is that it was cheap at the time and I wanted to get something as an experiment...so it works for me...if it falls apart in a year or two, short dollars to see what I could get. My main channels are about 53 miles away and I get all the ones I was interested in. Eventually I plan on upgrading to a Clearstream 2 with an amp at the base of the antenna.
 
#4 ·
My main channels are about 53 miles away and I get all the ones I was interested in. Eventually I plan on upgrading to a Clearstream 2 with an amp at the base of the antenna.
We're only a few miles further than you over mostly flat farmland then, is the Clearstream 2 something that's realistically an option for us? It's far smaller than anything we've had previously so easier to setup and less things to break.

This will be split off to 5 tv's and has been done before with the really large antennas and we've never needed an amp, is it just going to come down to trial and error if something smaller will work with an amp? Or should I just suck it up and put another monster on the roof to begin with?
 
#8 ·
I would suggest you use TVfool.com and Antennaweb.org. Both sites allow you to specify your location and they make recommendations about what type of antenna you should buy.

Wind can cause problems with OTA.

Unlike you I live in the middle of a city and I have problems with multi path. I use three antenna and need to move them around when the trees leaf out in the spring and leaves fall in the autumn. Small changes in the location of antenna and the direction the antenna is facing can make a big difference.

Antenna choice and placement is trial and error. I believe most people have few problems and a few people, like me have a difficult location. It is a good idea to buy an antenna somewhere where you can try it out and return it if it doesn't satisfy you.

I have had good luck with Channel Master antenna for over a decade. You might try a 4228 or a 4221
 
#9 · (Edited)
We now offer a VHF Retrofit kit that will clip right on a C2 or C4 antenna and will give it modest VHF performance (~ unity gain) on VHF channels 7-13. With noise margins on your high VHF stations in the low 30s, it will like do well on those stations, based on the TVFool plot.

However, the problem in Des Moines is WOI, one of about three dozen stations in the country that elected to remain on a low VHF allocation post-transition. Effective and efficient reception of a channel 5 signal usually requires antenna elements that are two to three times the length of the VHF Kit's elements. However, there are two things that make allow the C4 with VHF kit to do the job: 1) WOI transmits at about 14 kW from an 1800+ tower which, over the flat landscape in the area, gives them a coverage area of 70 -80 miles, and 2) WOI also operates a UHF translator from downtown whose signal might be receivable by a C4 in your location. The extra power on the VHF 5 channel is likely strong enough for the VHF-1's 35" dipole to pick up anyway, so you've got two opportunities to pick up WOI with a compact antenna, should you choose to go that route instead of the much larger all channel antenna suggested above.
 
#11 ·
Well we finally got around to getting a new antenna, a Winegard HD8200U. Currently it's fed directly into a single tv and all channels come in as long as the weather's nice. It's cloudy and rainy here this morning and channel 5 is dropping out even feeding the single television. We've tried splitting the signal and on a clear day channel 5 is a complete loss even adding a second tv.

The end goal is to split it 4-ways. Since it actually is picking up a signal what's our best option? I assume some kind of amplifier would work well in our situation.
 
#12 ·
Raining or a clear afternoon are times when temperature inversions are mostly non-existent and any help you're getting from ducting is at its lowest. This is telling you that you can only receive channel 5 with some ducting help which is common from around sunset though the morning. Unfortunately a preamp will not do much good on RF 5. It's possible you may have some noise issues on low VHF which is making 5 harder to receive than it should be. Even in my fairly quiet rural location the noise on low VHF is about 10 dB higher than on UHF and I suspect that 20 dB higher in city environments would not be uncommon. That means noise margins could be 10-20 dB lower than what TV Fool predicts.

Can you get WOI on RF 50 instead of RF 5?

A distribution amp would be a good idea for a 4-way split.
 
#15 ·
I went back up on the roof and got the antenna facing much closer to the 8-10 degrees that TV Fool shows it should be pointing. It was originally put up parallel to the ridge of the roof but that's basically due North. There's a marked increase in signal strength and I was able to run a four-way splitter successfully with not much degradation in signal.

I'm hoping adjusting the antenna itself is the solution and not just whatever "help" the ductwork is providing in the middle of the day. Would adding an amplifier still provide little or no help? Do we have any other options?
 
#17 ·
I'm hoping adjusting the antenna itself is the solution and not just whatever "help" the ductwork is providing in the middle of the day. Would adding an amplifier still provide little or no help? Do we have any other options?
You shouldn't even be able to see any difference in low VHF by moving the antenna 8-10 degrees. The 3 db beam width on low VHF is about 70 degrees. Could have been a change in conditions.

Not sure if you actually meant "ductwork." The "help" is coming from atmospheric ducting. :)

The reason preamps do little on low VHF is the environmental noise. To take advantage of a low noise figure preamp, the environmental noise has to be almost non-existent. 10 db of environmental noise on low VHF will completely swamp the low noise preamp and the result is you get almost no improvement. The real improvement is on high VHF and especially on UHF where the environmental noise is very low.

If channel 5 continues to be a problem and you want to pursue the problem, you need to devise a troubleshooting plan to determine what the problem actually is before you spend a bunch of money on ineffective solutions. I can tell you that it will be very difficult to get any significant gain on low VHF beyond what you already have with your HD8200U mounted outside. Such an antenna would have to be at least 20' long.

You need to determine whether the problem is actually signal strength (which I doubt) or signal quality (more likely). TV Fool is pretty accurate for LOS paths. You need to be able to determine the signal strength and compare that to your other channels. Most TVs don't have a real signal strength meter but only a Signal Quality meter, despite what they might call it. Sony TVs have a real signal strength meter. The HD Home Run and other computer based receivers have a real signal strength meter. Of course a spectrum analyzer works too.

Once you determine that the signal is strong enough, then you can look at possible multipath (unlikely with an outdoor antenna on low VHF) or interference, either from electronic devices nearby or noise from commercial power poles.
 
#16 ·
I'm looking for antenna recommendations, living out in the country the antenna's exposed to some pretty severe winds and everything we've had in the past has fallen apart.

I hope your HD8200U holds up but if yours breaks I'd consider building log periodics. The attached images show the antennas I have built for UHF, high VHF and low VHF. The wind is not going to blow these apart and I doubt ice would be an issue. The only problem I ran into was water ingress into the coax at the feed point which I solved by placing the end of a soda bottle over the feed point. That plastic is UV proof so it doesn't degrade.

The UHF antenna is very long for that frequency and was designed for high Front-to-Back ratio. I have the VHF antennas up now. I went with the 91XG for UHF because the gain is a little higher and weather isn't that much of an issue here. The high VHF antenna is better than anything you can buy now. The materials make the antennas more expensive than commercial antennas. Click on link below for details on the high VHF antenna.
 

Attachments

#19 ·
It's not clear to me from his post just what the situation is. At one point the station was dropping out with just one TV and then another test it was not okay with two TVs. TV Fool is not perfect on LOS signals either but it's not off 33 dB.... maybe 3 dB. There's something else going on. Whenever stuff like this doesn't make any sense it's because we don't have all the information. The next useful step is to find out what the signal strength is and how that compares to the other stations. Everything else is just guessing.

Preamps on low VHF are useless in almost all situations. If the environmental noise raises the noise at the antenna terminals 10 dB then that's like having a preamp with a 10 dB noise figure or worse. The environmental noise is setting the system noise figure instead of the preamp. The preamp gain will make the signal larger but the SNR doesn't change much.

As a case in point, unbeknownst to me I was operating with a partially blown out preamp for months on FM and never realized it. I swapped the FM antenna for a low VHF TV antenna. Initially I thought it was working fine as I was receiving the distant channel 2. One day I checked the channel 2 on a high VHF antenna and found that it received the station nearly as well. That didn't make any sense. Something was wrong. Missing information. I took down the preamp I was using for low VHF and measured it. The gain was 2 dB and the noise figure was 10 dB! I put in a replacement preamp with a 3.5 dB noise figure and 17 dB gain. I expected to see a 6 dB SNR improvement at least. Instead I got about 2 dB better SNR. After some calculations I found that I could have up to an 8 dB noise figure and there would be no difference in the SNR. A NF of 8 dB would be what I'd have if I used no preamp.
 
#21 ·
According to Rabbitears 5.1 maps to 5.1 and 50.1. He claims he can't receive 50.1 but that would make a lot more sense. Maybe this is the "missing information." Should it be that 5.1 maps to 50.1 on his TV and 50.1 tunes 50.1 then that would explain the whole thing. We have that situation in the Bay Area where 7.1 maps to both RF 7 and RF 35 and people often have no idea which station they are watching.

luisortega - When you tune to 5.1 are you sure your TV is on RF 5 and not on RF 50? Your experiences, and the signal predicted for RF 50 by TV Fool would indicate you're tuned to RF 50. It's very possible that since a channel scan would find RF 5 first and then RF 50, that it scans in RF 5 and then replaces it with RF 50 when it finds that signal.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top