Summer Heat Interferes With Reception?

[ralfyguy]

Since it is above 105F here every day now, and lows around 80 at night, could that be the cause for frequent dropouts at 90 miles distance, because the atmosphere actually really never cools off, even at night? I never had any more problems with reception than now. Checked all the equipment and everything seems ok. What do you think?

 

[lilyarbie]

Possibly, but can't guarantee...

I know weather plays a role in reception issues such as tropospheric ducting during warming and cool-down periods. Atmospheric changes are usually prone to helping channels come through, but I assume they could also hinder reception as well. Here's a link describing the tropospheric ducting effect that goes on during the Spring and fall periods mainly. It has a daily forecast showing you which areas are prone to higher reception of channels in different frequency bands and can be applied to VHF and UHF. You may have to change the map as I live in the southeastern United States and the link is set to that type of map. http://www.dxinfocentre.com/tropo.html

One other thing is that if you have a pre-amp on your antenna then it may be overheating in the process. Your metal on your antenna will work like a giant radiator of heat in the hot summer. It could possibly be heating your pre-amp to its threshold temperature and causing signal issues, even at night due to the fact it stays heated throughout the day and only gets a chance to cool down at night. This is just speculation, so it may just really be atmospheric changes. If you think it may be overheating then check your paper work for temperature thresholds and try sticking a thermometer to the metal in the middle of the day or late afternoon whenever its hottest outside and see what readings you get.

 

[ralfyguy]

I have checked all the connectors and thought about the overheating too, but I hooked up the RS preamp I had before, which is supposed to be 30db gain, with the same result. So it doesn't seem to be the amp. Also I observed that there's like a signal strength of 69 on some channels, and some are a little above 80, and then about 10 seconds later they drop enough to loose lock. And then it comes back. This is extreme during the day, not as frequent during the night. This all started when the temperatures went to triple digits a couple of weeks ago. Like I said, it is the same with a different amp, that was stored in the cool, before hooking it up. It ssems like the heat messes up the troposphere big time, and doesn't cool off enough during the night, as it is still above 80F then. In spring, when I installed the stuff, I had no problems at all. But since it is so hot now, I run into problems at 90 miles distance. Kinda a little miracle anyways to get that far on UHF, and having good signals. Th 91XG is really great. But seems with that distance and that much heat and trees and stuff, even that antenna doesn't cut it. I don't wanna erect no tower, because too expensive, and it's as high up on the roof as I could go with my fear of heights. Reception at long distances is always better at night, unless it's blowing hot. Other thing is, that here in Oklahoma the weather is kinda crazy. There's T-storms trying to build and then before they get strong enough to unload, they break apart again. So it's blazing humid here, and on the radar you can see the storms rotaing in circles across the state. The whole atmosphere is nothing but a mess lately. All this problems started when that weather mess started. So I think that's the main problem. It just sux to live that far from the towers, but there's nothing I can do about it. I put up the heaviest equipment available, and still get problems. I think if I wouldn't live on a hilltop, I wouldn't get anything at all. Remember the 60 miles rule, with everything beyond that is more or less just luck?

 

[roashru]

Summer heat interfering with reception problem could be at the antenna. me, im not a big fan of snap-together, unfolding, or temperature assembled antennas. these type of antennas perform differently under extreme temperature conditions.

Another possibility is if the antenna wasnt assembled properly using aluminum rivets. extreme temperature conditions would effect these antennas also.

 

[lilyarbie]

I think 60 miles is the average limit for UHF

I think UHF for the most part is limited at 60 miles on the average for reception. Anything beyond that I would say is pure luck. UHF unlike VHF goes more accordingly to the curvature of the earth. Once the signal hits the horizon, it floats off into space. During tropospheric ducting, the signal is trapped inside of an atmospheric signal duct that bounces the signal through the atmosphere to locations past 60 miles. You said that you had better reception in the Spring than during the summer. During the summer time, there is much less chance for ducting than during the Fall and Spring time. The atmosphere during these seasons is constantly changing due to the temperature falling and increasing more instead of staying constant for the most part like in the Winter and Summer time. You said the signal was more stable at night time? There is the atmospheric change during the night-time called nocturnal ducting. This is where the atmosphere is cooling down and therefore allows signals to duct. My nearest channel market is less than 30 miles away and comes in clear all the time. My next closest market is a little over 90 miles and only comes in periodically during night-time ducting with intermittent drop-outs. With a combination of tropospheric ducting and nocturnal ducting, most of the channels from that market come in strong enough without dropping out for hours.

 

[ralfyguy]

I think UHF for the most part is limited at 60 miles on the average for reception. Anything beyond that I would say is pure luck. UHF unlike VHF goes more accordingly to the curvature of the earth. Once the signal hits the horizon, it floats off into space. During tropospheric ducting, the signal is trapped inside of an atmospheric signal duct that bounces the signal through the atmosphere to locations past 60 miles. You said that you had better reception in the Spring than during the summer. During the summer time, there is much less chance for ducting than during the Fall and Spring time. The atmosphere during these seasons is constantly changing due to the temperature falling and increasing more instead of staying constant for the most part like in the Winter and Summer time. You said the signal was more stable at night time? There is the atmospheric change during the night-time called nocturnal ducting. This is where the atmosphere is cooling down and therefore allows signals to duct. My nearest channel market is less than 30 miles away and comes in clear all the time. My next closest market is a little over 90 miles and only comes in periodically during night-time ducting with intermittent drop-outs. With a combination of tropospheric ducting and nocturnal ducting, most of the channels from that market come in strong enough without dropping out for hours.

That's exactly what I figured. During spring or until a couple of weeks ago, I had all my local market channels come in fine without drop-outs 24/7. And then temperatures went to above 100F and that's when it started. So I'm just SOL until it gets cooler here again. And actually I was lucky all this time to get good reception at this distance. So no matter what I put on the roof and no matter what amp I put up there, this is apparently as good as it gets in my situation. It just sux, if the next local market is that far away. They should have put repeaters around here a little closer, because if I can't cut it with my nice equipment, and living on a hilltop, then no one else in this town can. I live in McAlester, OK, and my DMA is Tulsa in the North. The next DMA South is Sherman, TX at same distance, the next DMA East is Fort Smith, AK at about the same distance, and the next DMA West is ADA, OK at (you guessed) same distance. My location absolutely sux for OTA, that's why I tried the best stuff out there. I probably need a tower as tall as my stations, between 900 and 1500ft to get the job done