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https://www.antennasdirect.com/store...Combiners.html Inside the Antennas Direct UVSJ housing: http://forum.tvfool.com/attachment.p...1&d=1494170120 MCM also has one, but I have received mixed reports about its reliability. Maybe I'll have to order one and test it. http://www.mcmelectronics.com/product/33-2230 http://forum.tvfool.com/attachment.p...1&d=1494251768 If it gets any worse, we will have to make one like in the GE 34792 Attic Antenna: http://forum.tvfool.com/attachment.p...9&d=1494003888 http://forum.tvfool.com/attachment.p...0&d=1494003908 I have used the conventional terms for top and bottom of the board. The top is where the components are mounted and the bottom is where the ground plane is located. In actual use, the coax connector faces down. The GE 34792 Attic Antenna includes a REAL UVSJ, not shorting stubs, to keep the UHF and VHF signals separated before combining. Each section of the antenna has its own balun. The UVSJ and the well designed reflector are responsible for the good performance of this antenna. Here is a circuit of a UVSJ by SM0HX (amateur radio callsign for a ham in Sweden). The UVSJ UHF/VHF Separator-Joiner belongs to the filter family of Diplexers. All UVSJs are Diplexers, but not all Diplexers are UVSJs; Diplexer is the more general term. A HLSJ is also a Diplexer, but for VHF-Low and VHF-High. http://forum.tvfool.com/attachment.p...1&d=1494003982 The UHF highpass filter section has 3 series capacitors and 2 shunt inductors. The VHF lowpass filter section has 3 series inductors and 2 shunt capacitors. Here are the curves for the Radio Shack UVSJ: http://forum.tvfool.com/attachment.p...2&d=1494007033 Original post in RCA ANT751 thread: http://forum.tvfool.com/showpost.php...1&postcount=40 |
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If you happen to have a RS store still open in your 'hood, you might be able to score one locally. Do call ahead, though, inventory is pretty spotty in the remaining retail stores. Our UVSJ is still in production and is available. ;) |
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Here are the curves for the Antennas Direct UVSJ:
http://forum.tvfool.com/attachment.p...1&d=1494193827 |
thanks AD tech. but any idea where I can score one of your UVSJ's in NW Vermont?
Will the UVSJ allow me to install it at the pole ,connecting my existing antenna to the VHF side, and the new antenna to the UHF port, and run one cable into the house. Very important question. Will sending a signal boosted by 30Db do physical harm to my Roamio? |
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How do I order from your website? It's not obvious as to how. Update: After removing the Roamio from the distribution amp, the issue with WCAX is lots better so I am thinking of leaving things as they are. If the over load were harming my DVR, then..... Thanks for everything all |
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Thanks I see that, but can't find a UVSJ, or where it may be located. The only combiner I can find is this https://www.antennasdirect.com/store...Combiners.html
I think I need the UVSJ to combine the signals in my basement after the power injector for the antenna pre amp. |
UVSJ stands for "UHF/VHF Signal Joiner" Same device, you have found the correct item. Marketing decided to call it what they did, we've been using the common acronym for it. Sorry for any ambiguity. ;)
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I was looking for a smaller one to mount in the basement. I was lead to believe that the Antenna Direct would not pass power to my antenna pre amp. I think I was told to mount the UHF antenna pointer to my local channels and run a separate cable into the house and combine the cables "down stream" of the amps power tap. Is this not correct? Thanks Bear |
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Thanks, I'm getting a little lost in the technology. I understand analytical chemistry instruments, but your world is foreign to me.
I have one local VHF channel that I currently can get ( quite well via the back side of my antenna). In looking at my signal analysis chart I notice that CTV channel 6 from Montreal is not shown. It comes in quite well with my current set up. So this proposed setup using an un powered UHF antenna pointed at 111 degrees true azimuth will work. The remaining confusion is regarding the power pass diagram for the signal combiner. It indicates the power will not be shunted to my existing antenna, correct? My assumption is that my existing antenna will be connected to the VHF input of the combiner. Am I way off base? Thanks for your patience. Bear |
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Many years ago TV sets had separate inputs for VHF and UHF. The UHF/VHF Separator Joiner was developed to separate the UHF and VHF signals coming from the antenna to feed the separate inputs for two tuners. There were also UVSJs that would combine two 300 ohm antennas for a 75 ohm input TV. Some TVs had two 2-screw 300 ohm inputs, and some had a 75 ohm coax input for VHF and a 2-screw input for UHF where you could mount a UHF loop.
Separate tuners for UHF and VHF. To tune to a UHF channel, you would set the VHF channel selector to U, and then rotate the UHF dial. The output of the UHF tuner was sent to the input of the VHF tuner: http://forum.tvfool.com/attachment.p...1&d=1494355873 The 2 screws in the center are for VHF and have the internal antenna connected. The 2 screws on the right are for a UHF antenna: http://forum.tvfool.com/attachment.p...1&d=1494356524 This UVSJ combines a UHF and a VHF antenna for a 75 ohm coax input TV: http://forum.tvfool.com/attachment.p...1&d=1494355873 This UVSJ separates the UHF and VHF signals from a 75 ohm all-band antenna for a TV with separate 300 ohm UHF and VHF inputs: http://forum.tvfool.com/attachment.p...1&d=1494355873 The common use these days is to combine a UHF antenna with a VHF antenna for the single input of current TVs, but the UVSJ is a reciprocal device that can be used to combine UHF and VHF signals OR separate UHF and VHF signals. The UVSJ UHF/VHF Separator-Joiner belongs to the filter family of Diplexers. All UVSJs are Diplexers, but not all Diplexers are UVSJs; Diplexer is the more general term. A HLSJ is also a Diplexer, but for VHF-Low and VHF-High. |
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Also, make sure you are not confusing the virtual (displayed) channel number with the real channel number. For antenna purposes, we have to use the "real" channel number. CBMT-DT, for example, is operating on channel 21, not 6. |
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https://en.wikipedia.org/wiki/CFCF-DT http://www.rabbitears.info/market.ph...&callsign=cfcf https://en.wikipedia.org/wiki/CTV_Television_Network http://forum.tvfool.com/attachment.p...1&d=1494360023 |
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DB2E > coax > grounding > coax > Code:
DB2E > coax > http://forum.tvfool.com/attachment.p...1&d=1494369089 The power pass for the Antennas Direct UVSJ is also to UHF. The label on the Radio Shack pkg is misleading: http://forum.tvfool.com/attachment.p...1&d=1494370999 It is described as a splitter for two components, which is not correct. The Holland UVSJ passes DC to the VHF port, but there is no arrow: http://forum.tvfool.com/attachment.p...1&d=1494470497 Notice that it says Separator so that it doesn't get confused with a splitter, as happened here on this thread, creating a heated discussion: http://www.avsforum.com/forum/25-hdt...-combiner.html Inside: http://forum.tvfool.com/attachment.p...1&d=1494470497 I will try to find a UVSJ with power pass on the VHF side. If I can find one I will send it to you. Meanwhile, do a test with temporary coax lines and a second antenna for UHF to see if the plan will work. |
After reading other posts about poor reception, how much does being surrounded by trees contribute to my issue? There are lots of trees between me and Mt Mansfield.
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That would have been good to know much sooner. I did point out (twice) that we didn't know any details about your signal path (among other things). If trees are in the signal path, take any prediction made by the simulator and throw it out the window. Then, go outside and stomp on it a few times. For good measure, dig a hole and bury it. Then put a really big rock on top of it. The simulator's predictions are dead and buried since they are useless and no longer apply. I've personally visited a location what was less than 5 miles from a million watt UHF tower, and measured a >50 dB reduction in signal power when moving a mere 50 feet from a spot with LOS to one behind a mature wet silver maple tree. When the wind blew, the signal looked like it had gone through a shredder and reception failed. |
Ok, I'm sorry that I omitted the thing about the trees. Most of them are not mine so there is nothing to do about it other than to install the antenna on a 200' tower.
It must still be an issue with the roamio as the issue is with it only, and not the other 2 TV's in the system. Guess I'll monitor for a while as by taking the Roamio off the distribution amp things have gotten better. Again sorry, and thanks for all your help. |
the combination of trees and a mis-aimed antenna is killing you. One or the other by itself only works sometimes.
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