Posted on 01/15/2023 8:12:13 PM PST by Paul R.
Is there an inexpensive way to determine if poor over-the-air TV reception is due to weak signal strength vs. multipath reflections? I am trying to troubleshoot a problem with degraded OTA TV reception that has not responded to installing new cable and connectors. The antenna is fairly new and in good condition.
No on the 1st, unknown on the 2nd, but possible.
“Those silos” -sheesh. Long day...
I found this earlier this evening: A very interesting “out of the box” article from Channel Master that may well apply in some way to my situation:
https://www.channelmaster.com/blogs/free-tv/real-world-signal-propagation-what-you-need-to-know
Also, a good discussion regarding LTE interference. I would think newer TV’s would filter this out, which may explain why my newest TV seems to have better reception than my older ones. There may be other tuner improvements too (see link above which mentions problems overcome as “digital TV” developed.)
Oops, here’s the link:
https://www.channelmaster.com/blogs/free-tv/lte-filters-for-tv-antennas-what-you-need-to-know
Oh no problem, multitasking is the norm nowdays, same here. :)
What made me consider polarization was the indoor and homemade D-TV antennas. I noticed the elements are at about a 45 degree angle. And we know that they are not directional so I always wondered why. I have absolutely zero D-TV broadcasts to play with out here in the boonies or I would experiment with polarization.
But you might be on the right track with the polarization alteration from the tops of the silos, or the sides being round might be fanning the waves and causing some sort of self cancellation of the waves. It is kind of crazy though that you are so close to that one source and still can’t beam straight from it.
Honestly? I would try an amplifier. I know it is counter-intuitive being that close to the source, but it could boost what pure waves you are getting and cause the digital receiver to override the chaos. Kind of like how a digital FM radio goes in and out of “stereo” lock from terrestrial blockages when you have the LOC option on but doesn’t when you have LOC off.
Tell you what, on another note. We are all going to start having problems with these things as 5G becomes more common. I already had to replace my LNB on my C-Band dish with one that has a 4G-5G filter. They are utilizing the C-Band satellites for 5G and it goofed up my receiver trying to make sense of the chaos I am now receiving from these old birds.
I just thought of another consideration Paul. We are assuming that the close source you mention has THEIR equipment dialed in to the transmission frequency properly. It could be that they are off and why you are having trouble even though it is so close.
It might be a worthwhile effort to try and contact their technician and explain the issues you are having even though you are so close to their source. If you are having problems then others are also having the same problem.
And because this would be a detriment to their own business I am sure they would be interested enough to double check their equipment to make sure it is proper or not. Lot of times they just don’t know about issues like this because no one calls to let them know.
The problem very well could be TX and not RX. I recently had to do this with a local radio station. Turned out that somewhere in their repeater they had a cable loose and losing terminal contact with temperature changes. Been going on a month and no one had called to let them know.
The tech really appreciated it... :)
And some interesting stuff from 2009 about a change in broadcasting to Circular and Elliptical polarization.
“For some technical reason, during the recent repack more stations nationwide seemed to switch from horizontal to elliptical polarization. I believe an engineer stated this may be necessary for future ATSC 3.0 transmission, but I am not certain about that. But perhaps the benefits of elliptical may be better reception in fringe areas, or a better handling of multipath.”
https://www.avsforum.com/threads/ota-transmission-polarization.1138207/
Darn it... You got me hooked on this now friend. Silly question... Is this an old analog antenna you are trying? Or a newer digital antenna? It could be the antenna is just not efficiently covering the full band width it needs to.
I also found some interesting design concepts with this dual loop UHF antenna. This one is without reflectors, but reflector design to make this more directional are also available with a search.
https://www.instructables.com/Build-the-Pennyloop-UHF-Antenna/
OOPS, the reflector design is there also...
Some years back, I was acquainted with one of the techs at this station (close enough to go to his modest size wedding). But he’s moved on to bigger and better things (station in a largish city.) And he was more of a studio engr. anyway.
THIS station’s largest viewing population is actually the same direction as I am from the transmitter, but about 3x further away. SFAIK reception “in town” is generally ok. But I might ask around a little bit.
As an aside, our local talk radio station periodically gets into episodes of a week or more when there will be a minute or two of dead air before, say, the hourly national news. Normally commercials would play then, but, evidently something goes awry, and nobody is monitoring. On other stations I’ve seen, well, heard, instances of serious distortion that were not addressed for days or weeks. You’d think part of the chief engineer’s job would be to listen in once in a while! And, yeah, apparently no one calls until some infrequent listener / bub like me finally realizes it’s been going on for a while.
Anyway, I might just give the station a call.
One of our other area stations was forced to move frequency when the FCC sold off more of the formerly UHF TV spectrum. Reception was noticeably worse even pre-silos. I believe they have applied for a permit to increase their broadcast power quite a bit (well over 10x) but I have no idea how long approval takes — seems like that goes back at least a few years, so it may well be several!
Hahaha!
The present antenna is about 5 years old & made to cover UHF (likely the old UHF TV spectrum? I could measure the active element length - on a good day, that is) and high band VHF (on which one of our local stations still broadcasts).
I’d say there might be a chance the UHF section picks up LTE / etc. signals too well, and a filter or a newer amp with such a filter might help.
I was experimenting with an amplified indoor UHF / VHF antenna I picked up a couple weeks ago. It has LTE filtering. For a cheapy, it doesn’t do too badly, picking up a station ~32 miles away (with some intervening hills), though the 65 mile rating is a stretch (NOT picking up a station transmitting almost 2000 ft. HAAT on high VHF, and no real hills in between, either.) This cheapy does pick up our 7-mile-away station pretty cleanly, though. Curiously, it seems to pick up the weaker stations it can get, better at 5-6’ height, than mounted as high to the ceiling as I can p[ace it.
I’m thinking maybe an amp stated to have a LTE filter, or, put a LTE filter ahead of an amp, right on the mast.
IIRC Channel Master makes a quite good filter. Philips makes one too, but how good it is, is less certain.
(I have an old amp but I’m convinced interference causes it grief.)
“place it”
lol, now I am thoroughly confused with why you are having problems with the one closer source. I have some chores to do, let me think about this and get back later.
Thank you, because I am going to try again to get something here, maybe with antenna design. And I have not researched it in years now, so this is also good for me to dive back into. :)
I have a BUNCH of stuff to get done today too. Including prepping and smoking a turkey. :-)
Maybe if I get this one it will solve all my problems. /s
The range may be a bit overstated... ;-)
FWIW, the cheapy amplified UHF / VHF indoor antenna with LTE filtering seems to pick up the “7 mile” station fairly well. I’ll try it on the TV in our kitchen @ lunch.
A bit overstated? That is 6X the distance to the horizon in Kansas by line of sight... lol
I don’t know man, having a n amplifier is a huge plus but I wonder who would make such claims and whether to trust them because they did. I’ll bet that is a typo and it is supposed to be 48 miles? That would fit the capability of these better. :)
Bump!
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