Multipath, mountains and antenna stacking question

david_jr

SatelliteGuys Pro
Original poster
Pub Member / Supporter
May 7, 2007
2,704
998
Hancock, MA - The Berkshires
I live in the mountains of Western Massachusetts near the NY border just under 40 miles from (east of) the transmission towers. I have mountains in front of me (in relation to the Albany, NY tower) and the sides of me and directly in back of me. I have been working on OTA setup and am posting what I have done and asking a question at the end. I also posted this in the local AVS Forum for the Albany, NY HDTV DMA, but I figure there are smart people here who don't go there, so I came here also. Here is my Rabbit Ears info: RabbitEars.Info. I guess they don't update TV Fool anymore?

I kind of let my OTA setup go dark a couple years ago when I had to rebuild a wall on the side of my house that my OTA cable came through and I hadn't gotten around to running another cable from the antenna into the house. As luck would have it, my DISH Network satellite dish sits about 10 feet from my OTA antenna setup and I had 4 RG-6 lines going from the dish into the house through an eave and snaked down to my basement right near where my OTA dead Channel Master 7777 preamp (now replaced with an updated nearly identical model) and amplified splitter route my OTA out to the rooms of my house. So now my Sat dish is down to one wire (soon to be two when I install a second Hopper 3) so I repurposed one of the Sat lines to OTA. I got it working but was only able to get WRGB Channel 6, which is by far my strongest and most reliable OTA station. I haven't been able to play with it again until this week. I decided to take a small 24" Vizio TV that someone recently gave me over to my sister's house in Troy, NY where they have a small outdoor OTA Yagi antenna installed. I scanned 56 channels there pretty much everything available because they have no mountains in their way. My idea was to have the channels scanned in so I could use it as a reference to see what I might be able to pick up and it worked pretty well. For my OTA setup I have a Winegard HD8200U and an Antennas Direct XG91 stacked on the same 10 foot mast on a tripod on top of my roof at the peak, which is about 25 off the ground. That would put the top of my mast at 35 feet off the ground. My house sits at 1350 FT above sea level. In the past I have gotten most of the Albany channels reasonably watchable although dropouts and blockiness did occur except for Channel 6 (RF 6 from the Albany Tower [AT]) and CW 45 (that I got from the Jiminy Peak translator 1.6 miles to my southwest) which were both rock solid.

I decided to try to connect each of my antennas in their current configurations to see what I would get on the Vizio. My HD8200U has always been aimed just about directly at the AT and my XG91 has been pointed directly east of my house and at a slight angle up into Brodie Mountain where I was getting the UHF signals to bounce back to me. At the time I was also picking up CW 45 off the back of the same antenna on RF 19 off the WRGB Jiminy Peak translator. That translator is now RF 5. So I started with VHF and connected the HD8200U directly to my Vizio that I brought up on the roof with me. I cycled through the VHF stations 1 at a time and was only able to receive Channel 6 loud and proud. I decided to tune to Channel 13 and see if I could pick it up by rotating the antenna one way or the other. I tried about 10 to 15 degrees in each direction with no luck. So I decided to just keep rotating to see if it would make any difference and believe it or not, when I got to the direction pointing to Jiminy Peak, about 100 degrees left of the direction of AT I got locked steady signal on Channel 13! It locked on and stayed on steady with no dropouts. So I tried 23 and I got locked signal on it! Then I tried 51 and sure enough I got a locked steady signal on that!! Did I mention I love VHF? Well maybe not. So I figure I'll tune to Channel 6 and see if it works there too. No joy. Had to turn all the way back to face AT to get 6 back. Oh well onto UHF. So I decided to take my HD8200U down off the mast and carry it all the way to the other side of my roof about 45 feet away to avoid interference I had the XG91 at the top of the mast with the HD8200U about 5 feet below that on the mast. So I hook up the XG91 and tuned to Channel 10 (RF 24) and nothing, not a whiff of signal. I tried 17 (RF 25) and same thing, not a whiff. Tried aiming directly at AT, no joy. So I put up my 6 foot step ladder to check out the balun. Something seems really loose. So I take down the antenna (not easy because of rusted nuts) and discover that the coax cable was barely screwed onto the F connector and the balun was hanging out the back of its box. So I take that all apart and fix it up and put it back on the mast. I'm still tuned to Channel 10 but really getting nothing. So I start rotating slowly back and forth in the direction I know I have gotten UHF signal in the past and finally I got a faint quick hit of signal. Yes! The antenna still works. I tried Channel 17 too but wasn't getting any bites. I decided to go get another section of mast and lift the antenna up another 5 feet for a total of 15 feet off the roof, which I really didn't want to do because at that height I would have to guy it. It wasn't windy today so I decided to try it. So I'm up there at 15 feet and I seem to be getting signal but nothing really watchable. I tried that for a while, but really didn't get it to improve. So I decided to take the mast down and take the 5 foot section back off and connect the XG91 to it and try walking the roof with it to see if I could find a watchable UHF signal. So I connect it back up with the short mast sitting directly on the roof and the antenna at about 5 feet off the ground ready to start walking when I notice I have a solid steady signal of channel 10. It was pretty good. I decided to see what would happen if I took the slight elevation off the antenna and just have it level and that locked it up nicely. So I tried Channel 17 and I got a watchable picture on 17 too. I decided to cut my losses and just put the antennas back on the mast and see what I get.

So I decided to try putting the HD8200U at the top of the mast so that I could leave the XG91 down at the 5 foot level to try to avoid multipath from the antennas. I did a quick check and all VHF channels (6, 13, 23, and 51 all came in perfect at the new height, but again 6 came only in the direction of the AT and the others came in only in the direction of Jiminy Peak. So I decided to go in the direction of Jiminy Peak hoping that I would also get CW 45 off the translator, which carries Channel 6 on 45.3 and try another solution later to try for Channel 6. I hooked up my replacement Channel Master Antenna Preamp. Cut equal lengths of RG6 coax for each run from each antenna to the preamp and pressed on new terminals. I tidied up the wiring and connected the existing house feed coax from the previous satellite wire and began the arduous task of dragging all my tools and ladders back off the roof. I took my Vizio TV down to the basement where my CM preamp plugs in and where my splitter farm is and hooked everything up down there (except the splitter) and did a scan for channels. I got Channel10 with its subchannels, Channel 13 with its subchannels, Channel 17 with its subchannels, Channel 23 with its subchannels, Channel 45 with its subchannels twice!! (assuming RF 5 off the Jiminy Peak translator and RF 22 from AT), Channel 51 with its subchannels, and Channel55 with its subchannels!! Seemingly quite a success. Now I just have to figure out a way to get Channel 6. Would it be possible to get a third antenna up on my mast, maybe one of those small RCA Yagi's that might pick up Channel 6 and put a combiner in to see if it works? 6 has always been my strongest station. Or is it not worth pursuing?
 
  • Like
Reactions: FTA4PA
I live in the mountains of Western Massachusetts near the NY border just under 40 miles from (east of) the transmission towers. I have mountains in front of me (in relation to the Albany, NY tower) and the sides of me and directly in back of me. I have been working on OTA setup and am posting what I have done and asking a question at the end. I also posted this in the local AVS Forum for the Albany, NY HDTV DMA, but I figure there are smart people here who don't go there, so I came here also. Here is my Rabbit Ears info: RabbitEars.Info. I guess they don't update TV Fool anymore?

I kind of let my OTA setup go dark a couple years ago when I had to rebuild a wall on the side of my house that my OTA cable came through and I hadn't gotten around to running another cable from the antenna into the house. As luck would have it, my DISH Network satellite dish sits about 10 feet from my OTA antenna setup and I had 4 RG-6 lines going from the dish into the house through an eave and snaked down to my basement right near where my OTA dead Channel Master 7777 preamp (now replaced with an updated nearly identical model) and amplified splitter route my OTA out to the rooms of my house. So now my Sat dish is down to one wire (soon to be two when I install a second Hopper 3) so I repurposed one of the Sat lines to OTA. I got it working but was only able to get WRGB Channel 6, which is by far my strongest and most reliable OTA station. I haven't been able to play with it again until this week. I decided to take a small 24" Vizio TV that someone recently gave me over to my sister's house in Troy, NY where they have a small outdoor OTA Yagi antenna installed. I scanned 56 channels there pretty much everything available because they have no mountains in their way. My idea was to have the channels scanned in so I could use it as a reference to see what I might be able to pick up and it worked pretty well. For my OTA setup I have a Winegard HD8200U and an Antennas Direct XG91 stacked on the same 10 foot mast on a tripod on top of my roof at the peak, which is about 25 off the ground. That would put the top of my mast at 35 feet off the ground. My house sits at 1350 FT above sea level. In the past I have gotten most of the Albany channels reasonably watchable although dropouts and blockiness did occur except for Channel 6 (RF 6 from the Albany Tower [AT]) and CW 45 (that I got from the Jiminy Peak translator 1.6 miles to my southwest) which were both rock solid.

I decided to try to connect each of my antennas in their current configurations to see what I would get on the Vizio. My HD8200U has always been aimed just about directly at the AT and my XG91 has been pointed directly east of my house and at a slight angle up into Brodie Mountain where I was getting the UHF signals to bounce back to me. At the time I was also picking up CW 45 off the back of the same antenna on RF 19 off the WRGB Jiminy Peak translator. That translator is now RF 5. So I started with VHF and connected the HD8200U directly to my Vizio that I brought up on the roof with me. I cycled through the VHF stations 1 at a time and was only able to receive Channel 6 loud and proud. I decided to tune to Channel 13 and see if I could pick it up by rotating the antenna one way or the other. I tried about 10 to 15 degrees in each direction with no luck. So I decided to just keep rotating to see if it would make any difference and believe it or not, when I got to the direction pointing to Jiminy Peak, about 100 degrees left of the direction of AT I got locked steady signal on Channel 13! It locked on and stayed on steady with no dropouts. So I tried 23 and I got locked signal on it! Then I tried 51 and sure enough I got a locked steady signal on that!! Did I mention I love VHF? Well maybe not. So I figure I'll tune to Channel 6 and see if it works there too. No joy. Had to turn all the way back to face AT to get 6 back. Oh well onto UHF. So I decided to take my HD8200U down off the mast and carry it all the way to the other side of my roof about 45 feet away to avoid interference I had the XG91 at the top of the mast with the HD8200U about 5 feet below that on the mast. So I hook up the XG91 and tuned to Channel 10 (RF 24) and nothing, not a whiff of signal. I tried 17 (RF 25) and same thing, not a whiff. Tried aiming directly at AT, no joy. So I put up my 6 foot step ladder to check out the balun. Something seems really loose. So I take down the antenna (not easy because of rusted nuts) and discover that the coax cable was barely screwed onto the F connector and the balun was hanging out the back of its box. So I take that all apart and fix it up and put it back on the mast. I'm still tuned to Channel 10 but really getting nothing. So I start rotating slowly back and forth in the direction I know I have gotten UHF signal in the past and finally I got a faint quick hit of signal. Yes! The antenna still works. I tried Channel 17 too but wasn't getting any bites. I decided to go get another section of mast and lift the antenna up another 5 feet for a total of 15 feet off the roof, which I really didn't want to do because at that height I would have to guy it. It wasn't windy today so I decided to try it. So I'm up there at 15 feet and I seem to be getting signal but nothing really watchable. I tried that for a while, but really didn't get it to improve. So I decided to take the mast down and take the 5 foot section back off and connect the XG91 to it and try walking the roof with it to see if I could find a watchable UHF signal. So I connect it back up with the short mast sitting directly on the roof and the antenna at about 5 feet off the ground ready to start walking when I notice I have a solid steady signal of channel 10. It was pretty good. I decided to see what would happen if I took the slight elevation off the antenna and just have it level and that locked it up nicely. So I tried Channel 17 and I got a watchable picture on 17 too. I decided to cut my losses and just put the antennas back on the mast and see what I get.

So I decided to try putting the HD8200U at the top of the mast so that I could leave the XG91 down at the 5 foot level to try to avoid multipath from the antennas. I did a quick check and all VHF channels (6, 13, 23, and 51 all came in perfect at the new height, but again 6 came only in the direction of the AT and the others came in only in the direction of Jiminy Peak. So I decided to go in the direction of Jiminy Peak hoping that I would also get CW 45 off the translator, which carries Channel 6 on 45.3 and try another solution later to try for Channel 6. I hooked up my replacement Channel Master Antenna Preamp. Cut equal lengths of RG6 coax for each run from each antenna to the preamp and pressed on new terminals. I tidied up the wiring and connected the existing house feed coax from the previous satellite wire and began the arduous task of dragging all my tools and ladders back off the roof. I took my Vizio TV down to the basement where my CM preamp plugs in and where my splitter farm is and hooked everything up down there (except the splitter) and did a scan for channels. I got Channel10 with its subchannels, Channel 13 with its subchannels, Channel 17 with its subchannels, Channel 23 with its subchannels, Channel 45 with its subchannels twice!! (assuming RF 5 off the Jiminy Peak translator and RF 22 from AT), Channel 51 with its subchannels, and Channel55 with its subchannels!! Seemingly quite a success. Now I just have to figure out a way to get Channel 6. Would it be possible to get a third antenna up on my mast, maybe one of those small RCA Yagi's that might pick up Channel 6 and put a combiner in to see if it works? 6 has always been my strongest station. Or is it not worth pursuing?
That is one sad looking Rabbit Ears report. You have done very well considering and you should be proud! I have two antennas myself, a Stellar Labs 30-2370 and 30-2476, combined to get two edge reception past mountains from towers at 42 and 57 miles away. Currently using an RCA mast-mounted preamp fed into a Channel Master CM-3414 distribution amp. I am successfully feeding four tvs with the setup. As you did, I searched for around for a 'sweet spot' (higher, lower, etc) and tilted the antennas up slightly to take advantage of the knife-edge effect. Fortunately mine are on a mast behind our home so I did not have to (likely could not :rolleyes) get on the roof during the process. I will let someone else who has done so comment on adding a third antenna to the mix but just wanted to congratulate you on a job well done. :)
 
  • Like
Reactions: david_jr
Hi David Jr;

I’m glad you posted here. I no longer have access to the AVS Forum. (They were anal about rules over having two accounts, one personal and one for WRGB).

You have done well figuring out your options for reception of the Albany stations from your location.

I look at it this way, your 8200 is the best low band VHF antenna available. The 91 XG is the most directive UHF antenna available. If you added a high band VHF antenna to the mix, you could aim everything for optimum reception. The VHF antenna I have in mind is this Stellar labs; https://www.newark.com/stellar-labs/30-2476/deep-fringe-directional-antenna/dp/71Y5462
I would aim that antenna at Jiminy to pick up WXXA, WNYA, and WNYT.

The trick to combine the three antennas is to use a HLSJ to combine the 8200 with the Stellar Labs high band VHF antenna and then a UVSJ to combine the VHF pair with the UHF antenna. The output of the UVSJ would go to your preamp. It is not necessary to match cable lengths as the HLSJ and UVSJ block the unwanted signals from interfering with each other.

It is getting hard to find a HLSJ, but a bit of searching the net should get you one.

In addition to WRGB’s move to 35, WNYT just applied to move to channel 21. I don’t know the schedule for either of those moves. But assume that FCC delays and winter would delay WNYT’s move until next year. WRGB’s move will depend mostly on tower crew. availability.

Good Luck!
 
  • Like
Reactions: david_jr and FTA4PA
Hi David Jr;

I’m glad you posted here. I no longer have access to the AVS Forum. (They were anal about rules over having two accounts, one personal and one for WRGB).

You have done well figuring out your options for reception of the Albany stations from your location.

I look at it this way, your 8200 is the best low band VHF antenna available. The 91 XG is the most directive UHF antenna available. If you added a high band VHF antenna to the mix, you could aim everything for optimum reception. The VHF antenna I have in mind is this Stellar labs; https://www.newark.com/stellar-labs/30-2476/deep-fringe-directional-antenna/dp/71Y5462
I would aim that antenna at Jiminy to pick up WXXA, WNYA, and WNYT.

The trick to combine the three antennas is to use a HLSJ to combine the 8200 with the Stellar Labs high band VHF antenna and then a UVSJ to combine the VHF pair with the UHF antenna. The output of the UVSJ would go to your preamp. It is not necessary to match cable lengths as the HLSJ and UVSJ block the unwanted signals from interfering with each other.

It is getting hard to find a HLSJ, but a bit of searching the net should get you one.

In addition to WRGB’s move to 35, WNYT just applied to move to channel 21. I don’t know the schedule for either of those moves. But assume that FCC delays and winter would delay WNYT’s move until next year. WRGB’s move will depend mostly on tower crew. availability.

Good Luck!
Ok I ordered the Stellar Labs antenna. I also ordered this HLSJ SEPARATOR / JOINER HIGH LOW VHF FREQUENCY OFF AIR JVI HLSJ 736902313442 | eBay.

Do I actually need the UVSJ since my preamp Amplify+ Adjustable Gain Preamplifier for Professionals has separate VHF and UHF inputs?

Thanks again for your detailed instructions.
 
I have been thinking about the conundrum over the apparent stronger reflections off of Jiminy Peak on high band and UHF vs low band VHF. The strength of the reflections should not change with frequency. What does change with frequency is the strength of the direct signal. The advantage of low band VHF is its ability to “knife edge” over the tops of hills into shadowed areas. I’d guess that the direct signal from WRGB is strong enough to cause multipath with the reflected signal from Jiminy when your antenna is aimed at Jiminy.

Another possibility is a lower front to side ratio of the the low-V section of the 8200 vs the very directive UHF only 91 XG.

Lastly, antenna heights in hilly areas can do funny things to the vertical pattern of antennas. So, some heights and channels may favor an angle that aims to the top of Jiminy, and other heights and channels may favor the direct signal that is knife edging over your closer-in hilltop.

in any event, your original tests should get you a workable system with the added Hi-V antenna.
 
  • Like
Reactions: david_jr
I'm trying to improve the OTA signal at my mother's place by stacking 2 identical VHF antennas. What is the best, reasonably priced, low-loss combiner for this situation? Thanks.
 
I'm trying to improve the OTA signal at my mother's place by stacking 2 identical VHF antennas. What is the best, reasonably priced, low-loss combiner for this situation? Thanks.
If the two antennas will be aimed in the same direction, just use a two way splitter but backwards with the two outputs as inputs and the input would be the output.

The coax between each antenna and the splitter should be the same length.

if you post a rabbitears reception report for your mothers house, there might be other solutions to the reception problem.
 
  • Like
Reactions: TheKrell
I have been thinking about the conundrum over the apparent stronger reflections off of Jiminy Peak on high band and UHF vs low band VHF. The strength of the reflections should not change with frequency. What does change with frequency is the strength of the direct signal. The advantage of low band VHF is its ability to “knife edge” over the tops of hills into shadowed areas. I’d guess that the direct signal from WRGB is strong enough to cause multipath with the reflected signal from Jiminy when your antenna is aimed at Jiminy.

Another possibility is a lower front to side ratio of the the low-V section of the 8200 vs the very directive UHF only 91 XG.

Lastly, antenna heights in hilly areas can do funny things to the vertical pattern of antennas. So, some heights and channels may favor an angle that aims to the top of Jiminy, and other heights and channels may favor the direct signal that is knife edging over your closer-in hilltop.

in any event, your original tests should get you a workable system with the added Hi-V antenna.
I am in the mountains and finally accepted what I can get. Sometimes it is 60 channels, other times it is 20 channels. Between the weather and the vegetation, my stellar labs VHF hi and the uhf yagi get the job done as best as they can. Some days are great, others not so much. When in a borderline area one rain cloud can make a difference.
 
I can drive a half mile from here and see WYFF4 tower in the distance, but being in a hole aka valley it shoots over me. A storm up on the mountain made it cut out continually tonight even though it was clear here 30 miles away.
 
If the two antennas will be aimed in the same direction, just use a two way splitter but backwards with the two outputs as inputs and the input would be the output.

The coax between each antenna and the splitter should be the same length.

if you post a rabbitears reception report for your mothers house, there might be other solutions to the reception problem.

Hope this link works:


She's trying to get the first two on the list
 
Hope this link works:


She's trying to get the first two on the list
OUCH.
Those channels are both LOW VHF, which means you NEED an antenna capable of getting LOW Vhf. Those types are HUGE, and you likely can't stack them. Most VHF antennas that are easy to get are only HIGH Vhf.

She has NO chance of getting those, except by occasional Tropo. IF you click on the mileage hyperlinks, here's what you are fighting. the signal has to go THROUGH the mountain range. The red dotted line is the path the signal would need to get to her house.

Screenshot 2021-09-01 at 21-37-21 RabbitEars Info.png
 
I'm getting those stations at my house, not far away, with an old VHF low antenna and the Kitztech KT-500-Coax preamp.

Here's the rabbitears reception report for my location: RabbitEars.Info

For some reason, the signal seems to be weaker at her location.
 
Note that KTVM has FCC permission to move to UHF. So any reception of that low-VHF signal would be temporary.

I won't be surprised if KXLF follows. No shortage of open UHF channels there.

- Trip
 
Note that KTVM has FCC permission to move to UHF. So any reception of that low-VHF signal would be temporary.

I won't be surprised if KXLF follows. No shortage of open UHF channels there.

- Trip
KXLF and KTVM have been on VHF-low from analog days. I sure hope they don't leave VHF -- I think UHF would be even harder to receive at this location.
 
  • Like
Reactions: TheKrell
KTVM is already approved. Unless something drastic changes, and Sinclair has historically completed their VHF-to-UHF moves, it's going to happen. It's a matter of when, not if.

KXLF hasn't filed anything, but I have to imagine they won't want to remain as the sole low-VHF station. When they were one of two, it was easier to justify since viewers would be out both CBS and NBC without a low-VHF antenna, but I can't imagine them wanting to be the only one.

- Trip
 
KTVM is already approved. Unless something drastic changes, and Sinclair has historically completed their VHF-to-UHF moves, it's going to happen. It's a matter of when, not if.

KXLF hasn't filed anything, but I have to imagine they won't want to remain as the sole low-VHF station. When they were one of two, it was easier to justify since viewers would be out both CBS and NBC without a low-VHF antenna, but I can't imagine them wanting to be the only one.

- Trip
Guess we'll just be out of luck for local television
 
I emailed KTVM and this is the reply I got back:





Thank you for contacting us. As of right now it will be several years before we move KTVM into the UHF band. The new technologies that are on the horizon do not function well in the VHF band and that is why a lot of broadcasters will be moving in the next several years. That being said, the FCC requires that we submit engineering data that shows we will not significantly change our coverage area. This will be achieved by significantly increasing our power level. For example it looks like we will be moving from an output power of 4KW to an output power of 1MW. This should be enough power to cover our current VHF footprint. I hope that this answers your question. If you have any other questions or concerns please feel free to contact us.



Regards,



Robert Owen
Director of Engineering
KECI| KCFW | KTVM
 
  • Like
Reactions: primestar31