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#31
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jg wrote:
Funny that you mention that. I have a linux box that I've setup with MythTV. I've also tried Freevo. Not to get too far off-topic, but how's that working out for you? I've always been intrigued by the idea of MythTV. |
#32
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On Sun, 12 Feb 2006 13:25:44 GMT, "Ralph Mowery"
wrote: "Tony Hwang" wrote in message news:meBHf.602959$ki.30465@pd7tw2no... jg wrote: Hi, Twin lead also has better quality foam ones not the skinny twirly kind. Coiling up extra coax is not a good idea it can act like RF choke and could lower signal level. Tony Coiling up extra coax wil not make it like a RF choke and will not lower the signal level. As long as the coil diameter is large enough that the center conductor does not cut into the iner insulation and short to the shield, nothing on the outside of the coax will affect the strength of the signal. The signal is carried on the inside of the outer shield. Coil up all the extra you want. One thing that will affect the signal is if you have way too much coiled up (like 20 or more feet) is the extra loss in the length of coax. YOu will get the same ammount of loss if it is coiled or just ran in a line. If you are transmitting , coiling up the coax may have a benifit as it will act as a choke and keep the transmitted rf that is coupled from the antenna You sound like you know what you're talking about, but one thing gets me. Here you say it will act as a choke and at the start of the previous paragraph you say it won't. Why does transmission have a different result from reception, or is there some other difference? from getting back to the transmitter. Discussion on this is beyond the TV application and not needed here. Remove NOPSAM to email me. Please let me know if you have posted also. |
#33
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#34
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![]() "mm" wrote in message ... On Sun, 12 Feb 2006 13:25:44 GMT, "Ralph Mowery" wrote: "Tony Hwang" wrote in message news:meBHf.602959$ki.30465@pd7tw2no... jg wrote: Hi, Twin lead also has better quality foam ones not the skinny twirly kind. Coiling up extra coax is not a good idea it can act like RF choke and could lower signal level. Tony Coiling up extra coax wil not make it like a RF choke and will not lower the signal level. As long as the coil diameter is large enough that the center conductor does not cut into the iner insulation and short to the shield, nothing on the outside of the coax will affect the strength of the signal. The signal is carried on the inside of the outer shield. Coil up all the extra you want. One thing that will affect the signal is if you have way too much coiled up (like 20 or more feet) is the extra loss in the length of coax. YOu will get the same ammount of loss if it is coiled or just ran in a line. If you are transmitting , coiling up the coax may have a benifit as it will act as a choke and keep the transmitted rf that is coupled from the antenna You sound like you know what you're talking about, but one thing gets me. Here you say it will act as a choke and at the start of the previous paragraph you say it won't. Why does transmission have a different result from reception, or is there some other difference? from getting back to the transmitter. Discussion on this is beyond the TV application and not needed here. I have been a ham radio operator for over 30 years and at one time held a first class phone license that was good for the comercial radio repair. When receiving the signal comes from the antenna it comes down on the outside of the inner wire and the inside of the outer sheild. Unlike Direct current which uses all the wire area, as the frequency goes up, the signal only uses part of the area. That is a copper tube can carry just as much signal as a solid wire the same diameter. Large coax (usually called hardline) is often made this way. There is nothing useful on the outside of the shield of the coax. In otherwords everything from the receiving antenna is on the inside of the coax and coiling it up has no effect . When transmiting it is possiable that some of the signal from the antenna will couple or be introduced on the outside of the coax. This unwanted signal will come back down the coax on the outside of the shield and can cause problems with the transmitter and other electronics in the house. If the coax is wound in a coil it may choke off this unwanted signal. The coil is usually placed outside the house . |
#35
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Ok, so is it possible to have both my current antenna pointed in one
direction (minus the UHF section) and use this new antenna pointed in a different direction? Then just combine the signal? This would give me the best of both world w/o the need for a rotor. |
#36
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![]() You seem to know a lot. Here's a question, if my mast is well grounded (buried a few feet) do I still need to ground the coax before it enters the house? The way I see it, the mast will dissipate any charge on the antenna? Yes? |
#37
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In article .com,
jg wrote: Ok, so is it possible to have both my current antenna pointed in one direction (minus the UHF section) and use this new antenna pointed in a different direction? Then just combine the signal? This would give me the best of both world w/o the need for a rotor. Sure. Back in the dark ages, when the UHF channels went up to Channel 83, TV sets didn't have a combined antenna input, instead they had two (usually 300 ohm) inputs, one for each band. To save cable, VHF/UHF splitter/combiners were used if you had an all band antenna. They're bidirectional, the same unit can be used either way. So you can run two antennas into the one cable. Mark Zenier Googleproofaddress(account:mzenier provider:eskimo domain:com) |
#38
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Thanx to all who replied and helped out. I've installed a balun
tranformer at the antenna and I've replaced the entire run with RJ6 coax cable. Picture quality increased drastically on all channels. I've got my antenna pointing 206 degrees yet I can still pick up channels 29 (103 degrees) and 19 (143 degrees.) (My antenna's fault I'm sure.) At any rate the local stations (Sacramento) all come in super clear, so I'll leave it as it is. Thanx again. |
#39
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![]() "jg" wrote in message oups.com... Thanx to all who replied and helped out. I've installed a balun tranformer at the antenna and I've replaced the entire run with RJ6 coax cable. Picture quality increased drastically on all channels. I've got my antenna pointing 206 degrees yet I can still pick up channels 29 (103 degrees) and 19 (143 degrees.) (My antenna's fault I'm sure.) At any rate the local stations (Sacramento) all come in super clear, so I'll leave it as it is. Thanx again. If you ever get the urge, buy a good long distance antenna and put a rotor on it and see what you get! B |
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