Unlicensed TV broadcasting power limit (Band I)












4














I'm curious what is the legal limit for unlicensed TV signals being transmitted on the VHF Band I?



This seems ill defined. The part 15 FM rules I am assuming don't apply here. And I don't think it can be illegal at all power levels because even old VCRs and TV tuners will leak a little RF. So what is the limit?










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    4














    I'm curious what is the legal limit for unlicensed TV signals being transmitted on the VHF Band I?



    This seems ill defined. The part 15 FM rules I am assuming don't apply here. And I don't think it can be illegal at all power levels because even old VCRs and TV tuners will leak a little RF. So what is the limit?










    share|improve this question

























      4












      4








      4







      I'm curious what is the legal limit for unlicensed TV signals being transmitted on the VHF Band I?



      This seems ill defined. The part 15 FM rules I am assuming don't apply here. And I don't think it can be illegal at all power levels because even old VCRs and TV tuners will leak a little RF. So what is the limit?










      share|improve this question













      I'm curious what is the legal limit for unlicensed TV signals being transmitted on the VHF Band I?



      This seems ill defined. The part 15 FM rules I am assuming don't apply here. And I don't think it can be illegal at all power levels because even old VCRs and TV tuners will leak a little RF. So what is the limit?







      united-states legal vhf transmitter






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      asked 2 days ago









      Synaps3Synaps3

      1684




      1684






















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          It's illegal at all power levels. If you "leak a little RF" then there is something in Part 15 that applies (e.g. this section for VCRs and cable boxes) and the device needs to be certified. If you broadcast intentionally then there isn't anything that allows it at all, at any power level.






          share|improve this answer





















          • "and the device needs to be certified" is not correct. There are many non-certified allowances described in Part 15. A topical one of interest to hams is that "white goods" are completely exempted from the part 15 regulations and yet they are an increasing source of RFI due to variable speed drives and increased uP control.
            – Glenn W9IQ
            yesterday










          • "If you broadcast intentionally then there isn't anything that allows it at all" is also not true. Part 15 describes intentional "broadcast" devices that are permitted. Subpart C specifically allows low power, unlicensed AM and FM transmitters.
            – Glenn W9IQ
            yesterday










          • @GlennW9IQ yes, but not TV, which is what this question is about...
            – hobbs - KC2G
            yesterday










          • That is not correct. You may wish to read my answer and specifically read 15.701.-.711.
            – Glenn W9IQ
            yesterday



















          4














          Since you mentioned part 15, I'm guessing you're asking about the rules in the United States.



          If you look at part 15 subpart C in detail, you'll see that the frequencies in the VHF I band (44 - 87.5 MHz) have some specific unlicensed uses, mostly related to audio transmissions (wireless microphones, cordless phones, etc.) Since the question is about TV signals, most of those don't apply. The only exception I can see is §15.235, which doesn't specify a specific application (except for saying that it can't be a cordless phone). However, that section is for a very narrow band: 49.82-49.90 MHz. Since NTSC signals require 6 MHz of bandwidth, that band isn't nearly big enough to accommodate a typical video application.



          That leaves white space devices as the last remaining option. The rules for these devices are complicated. The available frequencies vary by location and time. The maximum allowed power levels vary depending on the frequency and the characteristics of the device. It's possible to transmit with a range of several kilometers with the right gear, but you have to carefully follow some fairly complicated rules.



          Because the question referenced unintentional leakage, I'll point out that it's covered by different rules. Part 15 subpart B has the specifics.






          share|improve this answer



















          • 1




            Wikipedia is not an authoritative or comprehensive source. Read part C.F.R. 47 §§ 15.701-.711 to see that this is permitted under limited conditions.
            – Glenn W9IQ
            yesterday










          • @GlennW9IQ Thank you for point that out. I updated my answer to include information about white space devices.
            – mrog
            yesterday



















          2














          Yes, you may broadcast (called an "intentional radiator") video transmissions but only on unused TV channels 14-51 (UHF, not VHF) as so called "white spaces". Read Part 15 regulations part 701 and on for the requirements and restrictions. Here is the introduction to this section:





          This subpart sets forth the regulations for unlicensed white space devices. These devices are unlicensed intentional radiators that operate on available TV channels in the broadcast television frequency bands, the 600 MHz band (including the guard bands and duplex gap), and in 608-614 MHz (channel 37).





          Also reference the FCC web site on this topic.






          share|improve this answer























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            3 Answers
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            It's illegal at all power levels. If you "leak a little RF" then there is something in Part 15 that applies (e.g. this section for VCRs and cable boxes) and the device needs to be certified. If you broadcast intentionally then there isn't anything that allows it at all, at any power level.






            share|improve this answer





















            • "and the device needs to be certified" is not correct. There are many non-certified allowances described in Part 15. A topical one of interest to hams is that "white goods" are completely exempted from the part 15 regulations and yet they are an increasing source of RFI due to variable speed drives and increased uP control.
              – Glenn W9IQ
              yesterday










            • "If you broadcast intentionally then there isn't anything that allows it at all" is also not true. Part 15 describes intentional "broadcast" devices that are permitted. Subpart C specifically allows low power, unlicensed AM and FM transmitters.
              – Glenn W9IQ
              yesterday










            • @GlennW9IQ yes, but not TV, which is what this question is about...
              – hobbs - KC2G
              yesterday










            • That is not correct. You may wish to read my answer and specifically read 15.701.-.711.
              – Glenn W9IQ
              yesterday
















            4














            It's illegal at all power levels. If you "leak a little RF" then there is something in Part 15 that applies (e.g. this section for VCRs and cable boxes) and the device needs to be certified. If you broadcast intentionally then there isn't anything that allows it at all, at any power level.






            share|improve this answer





















            • "and the device needs to be certified" is not correct. There are many non-certified allowances described in Part 15. A topical one of interest to hams is that "white goods" are completely exempted from the part 15 regulations and yet they are an increasing source of RFI due to variable speed drives and increased uP control.
              – Glenn W9IQ
              yesterday










            • "If you broadcast intentionally then there isn't anything that allows it at all" is also not true. Part 15 describes intentional "broadcast" devices that are permitted. Subpart C specifically allows low power, unlicensed AM and FM transmitters.
              – Glenn W9IQ
              yesterday










            • @GlennW9IQ yes, but not TV, which is what this question is about...
              – hobbs - KC2G
              yesterday










            • That is not correct. You may wish to read my answer and specifically read 15.701.-.711.
              – Glenn W9IQ
              yesterday














            4












            4








            4






            It's illegal at all power levels. If you "leak a little RF" then there is something in Part 15 that applies (e.g. this section for VCRs and cable boxes) and the device needs to be certified. If you broadcast intentionally then there isn't anything that allows it at all, at any power level.






            share|improve this answer












            It's illegal at all power levels. If you "leak a little RF" then there is something in Part 15 that applies (e.g. this section for VCRs and cable boxes) and the device needs to be certified. If you broadcast intentionally then there isn't anything that allows it at all, at any power level.







            share|improve this answer












            share|improve this answer



            share|improve this answer










            answered yesterday









            hobbs - KC2Ghobbs - KC2G

            69528




            69528












            • "and the device needs to be certified" is not correct. There are many non-certified allowances described in Part 15. A topical one of interest to hams is that "white goods" are completely exempted from the part 15 regulations and yet they are an increasing source of RFI due to variable speed drives and increased uP control.
              – Glenn W9IQ
              yesterday










            • "If you broadcast intentionally then there isn't anything that allows it at all" is also not true. Part 15 describes intentional "broadcast" devices that are permitted. Subpart C specifically allows low power, unlicensed AM and FM transmitters.
              – Glenn W9IQ
              yesterday










            • @GlennW9IQ yes, but not TV, which is what this question is about...
              – hobbs - KC2G
              yesterday










            • That is not correct. You may wish to read my answer and specifically read 15.701.-.711.
              – Glenn W9IQ
              yesterday


















            • "and the device needs to be certified" is not correct. There are many non-certified allowances described in Part 15. A topical one of interest to hams is that "white goods" are completely exempted from the part 15 regulations and yet they are an increasing source of RFI due to variable speed drives and increased uP control.
              – Glenn W9IQ
              yesterday










            • "If you broadcast intentionally then there isn't anything that allows it at all" is also not true. Part 15 describes intentional "broadcast" devices that are permitted. Subpart C specifically allows low power, unlicensed AM and FM transmitters.
              – Glenn W9IQ
              yesterday










            • @GlennW9IQ yes, but not TV, which is what this question is about...
              – hobbs - KC2G
              yesterday










            • That is not correct. You may wish to read my answer and specifically read 15.701.-.711.
              – Glenn W9IQ
              yesterday
















            "and the device needs to be certified" is not correct. There are many non-certified allowances described in Part 15. A topical one of interest to hams is that "white goods" are completely exempted from the part 15 regulations and yet they are an increasing source of RFI due to variable speed drives and increased uP control.
            – Glenn W9IQ
            yesterday




            "and the device needs to be certified" is not correct. There are many non-certified allowances described in Part 15. A topical one of interest to hams is that "white goods" are completely exempted from the part 15 regulations and yet they are an increasing source of RFI due to variable speed drives and increased uP control.
            – Glenn W9IQ
            yesterday












            "If you broadcast intentionally then there isn't anything that allows it at all" is also not true. Part 15 describes intentional "broadcast" devices that are permitted. Subpart C specifically allows low power, unlicensed AM and FM transmitters.
            – Glenn W9IQ
            yesterday




            "If you broadcast intentionally then there isn't anything that allows it at all" is also not true. Part 15 describes intentional "broadcast" devices that are permitted. Subpart C specifically allows low power, unlicensed AM and FM transmitters.
            – Glenn W9IQ
            yesterday












            @GlennW9IQ yes, but not TV, which is what this question is about...
            – hobbs - KC2G
            yesterday




            @GlennW9IQ yes, but not TV, which is what this question is about...
            – hobbs - KC2G
            yesterday












            That is not correct. You may wish to read my answer and specifically read 15.701.-.711.
            – Glenn W9IQ
            yesterday




            That is not correct. You may wish to read my answer and specifically read 15.701.-.711.
            – Glenn W9IQ
            yesterday











            4














            Since you mentioned part 15, I'm guessing you're asking about the rules in the United States.



            If you look at part 15 subpart C in detail, you'll see that the frequencies in the VHF I band (44 - 87.5 MHz) have some specific unlicensed uses, mostly related to audio transmissions (wireless microphones, cordless phones, etc.) Since the question is about TV signals, most of those don't apply. The only exception I can see is §15.235, which doesn't specify a specific application (except for saying that it can't be a cordless phone). However, that section is for a very narrow band: 49.82-49.90 MHz. Since NTSC signals require 6 MHz of bandwidth, that band isn't nearly big enough to accommodate a typical video application.



            That leaves white space devices as the last remaining option. The rules for these devices are complicated. The available frequencies vary by location and time. The maximum allowed power levels vary depending on the frequency and the characteristics of the device. It's possible to transmit with a range of several kilometers with the right gear, but you have to carefully follow some fairly complicated rules.



            Because the question referenced unintentional leakage, I'll point out that it's covered by different rules. Part 15 subpart B has the specifics.






            share|improve this answer



















            • 1




              Wikipedia is not an authoritative or comprehensive source. Read part C.F.R. 47 §§ 15.701-.711 to see that this is permitted under limited conditions.
              – Glenn W9IQ
              yesterday










            • @GlennW9IQ Thank you for point that out. I updated my answer to include information about white space devices.
              – mrog
              yesterday
















            4














            Since you mentioned part 15, I'm guessing you're asking about the rules in the United States.



            If you look at part 15 subpart C in detail, you'll see that the frequencies in the VHF I band (44 - 87.5 MHz) have some specific unlicensed uses, mostly related to audio transmissions (wireless microphones, cordless phones, etc.) Since the question is about TV signals, most of those don't apply. The only exception I can see is §15.235, which doesn't specify a specific application (except for saying that it can't be a cordless phone). However, that section is for a very narrow band: 49.82-49.90 MHz. Since NTSC signals require 6 MHz of bandwidth, that band isn't nearly big enough to accommodate a typical video application.



            That leaves white space devices as the last remaining option. The rules for these devices are complicated. The available frequencies vary by location and time. The maximum allowed power levels vary depending on the frequency and the characteristics of the device. It's possible to transmit with a range of several kilometers with the right gear, but you have to carefully follow some fairly complicated rules.



            Because the question referenced unintentional leakage, I'll point out that it's covered by different rules. Part 15 subpart B has the specifics.






            share|improve this answer



















            • 1




              Wikipedia is not an authoritative or comprehensive source. Read part C.F.R. 47 §§ 15.701-.711 to see that this is permitted under limited conditions.
              – Glenn W9IQ
              yesterday










            • @GlennW9IQ Thank you for point that out. I updated my answer to include information about white space devices.
              – mrog
              yesterday














            4












            4








            4






            Since you mentioned part 15, I'm guessing you're asking about the rules in the United States.



            If you look at part 15 subpart C in detail, you'll see that the frequencies in the VHF I band (44 - 87.5 MHz) have some specific unlicensed uses, mostly related to audio transmissions (wireless microphones, cordless phones, etc.) Since the question is about TV signals, most of those don't apply. The only exception I can see is §15.235, which doesn't specify a specific application (except for saying that it can't be a cordless phone). However, that section is for a very narrow band: 49.82-49.90 MHz. Since NTSC signals require 6 MHz of bandwidth, that band isn't nearly big enough to accommodate a typical video application.



            That leaves white space devices as the last remaining option. The rules for these devices are complicated. The available frequencies vary by location and time. The maximum allowed power levels vary depending on the frequency and the characteristics of the device. It's possible to transmit with a range of several kilometers with the right gear, but you have to carefully follow some fairly complicated rules.



            Because the question referenced unintentional leakage, I'll point out that it's covered by different rules. Part 15 subpart B has the specifics.






            share|improve this answer














            Since you mentioned part 15, I'm guessing you're asking about the rules in the United States.



            If you look at part 15 subpart C in detail, you'll see that the frequencies in the VHF I band (44 - 87.5 MHz) have some specific unlicensed uses, mostly related to audio transmissions (wireless microphones, cordless phones, etc.) Since the question is about TV signals, most of those don't apply. The only exception I can see is §15.235, which doesn't specify a specific application (except for saying that it can't be a cordless phone). However, that section is for a very narrow band: 49.82-49.90 MHz. Since NTSC signals require 6 MHz of bandwidth, that band isn't nearly big enough to accommodate a typical video application.



            That leaves white space devices as the last remaining option. The rules for these devices are complicated. The available frequencies vary by location and time. The maximum allowed power levels vary depending on the frequency and the characteristics of the device. It's possible to transmit with a range of several kilometers with the right gear, but you have to carefully follow some fairly complicated rules.



            Because the question referenced unintentional leakage, I'll point out that it's covered by different rules. Part 15 subpart B has the specifics.







            share|improve this answer














            share|improve this answer



            share|improve this answer








            edited yesterday

























            answered yesterday









            mrogmrog

            28419




            28419








            • 1




              Wikipedia is not an authoritative or comprehensive source. Read part C.F.R. 47 §§ 15.701-.711 to see that this is permitted under limited conditions.
              – Glenn W9IQ
              yesterday










            • @GlennW9IQ Thank you for point that out. I updated my answer to include information about white space devices.
              – mrog
              yesterday














            • 1




              Wikipedia is not an authoritative or comprehensive source. Read part C.F.R. 47 §§ 15.701-.711 to see that this is permitted under limited conditions.
              – Glenn W9IQ
              yesterday










            • @GlennW9IQ Thank you for point that out. I updated my answer to include information about white space devices.
              – mrog
              yesterday








            1




            1




            Wikipedia is not an authoritative or comprehensive source. Read part C.F.R. 47 §§ 15.701-.711 to see that this is permitted under limited conditions.
            – Glenn W9IQ
            yesterday




            Wikipedia is not an authoritative or comprehensive source. Read part C.F.R. 47 §§ 15.701-.711 to see that this is permitted under limited conditions.
            – Glenn W9IQ
            yesterday












            @GlennW9IQ Thank you for point that out. I updated my answer to include information about white space devices.
            – mrog
            yesterday




            @GlennW9IQ Thank you for point that out. I updated my answer to include information about white space devices.
            – mrog
            yesterday











            2














            Yes, you may broadcast (called an "intentional radiator") video transmissions but only on unused TV channels 14-51 (UHF, not VHF) as so called "white spaces". Read Part 15 regulations part 701 and on for the requirements and restrictions. Here is the introduction to this section:





            This subpart sets forth the regulations for unlicensed white space devices. These devices are unlicensed intentional radiators that operate on available TV channels in the broadcast television frequency bands, the 600 MHz band (including the guard bands and duplex gap), and in 608-614 MHz (channel 37).





            Also reference the FCC web site on this topic.






            share|improve this answer




























              2














              Yes, you may broadcast (called an "intentional radiator") video transmissions but only on unused TV channels 14-51 (UHF, not VHF) as so called "white spaces". Read Part 15 regulations part 701 and on for the requirements and restrictions. Here is the introduction to this section:





              This subpart sets forth the regulations for unlicensed white space devices. These devices are unlicensed intentional radiators that operate on available TV channels in the broadcast television frequency bands, the 600 MHz band (including the guard bands and duplex gap), and in 608-614 MHz (channel 37).





              Also reference the FCC web site on this topic.






              share|improve this answer


























                2












                2








                2






                Yes, you may broadcast (called an "intentional radiator") video transmissions but only on unused TV channels 14-51 (UHF, not VHF) as so called "white spaces". Read Part 15 regulations part 701 and on for the requirements and restrictions. Here is the introduction to this section:





                This subpart sets forth the regulations for unlicensed white space devices. These devices are unlicensed intentional radiators that operate on available TV channels in the broadcast television frequency bands, the 600 MHz band (including the guard bands and duplex gap), and in 608-614 MHz (channel 37).





                Also reference the FCC web site on this topic.






                share|improve this answer














                Yes, you may broadcast (called an "intentional radiator") video transmissions but only on unused TV channels 14-51 (UHF, not VHF) as so called "white spaces". Read Part 15 regulations part 701 and on for the requirements and restrictions. Here is the introduction to this section:





                This subpart sets forth the regulations for unlicensed white space devices. These devices are unlicensed intentional radiators that operate on available TV channels in the broadcast television frequency bands, the 600 MHz band (including the guard bands and duplex gap), and in 608-614 MHz (channel 37).





                Also reference the FCC web site on this topic.







                share|improve this answer














                share|improve this answer



                share|improve this answer








                edited yesterday

























                answered yesterday









                Glenn W9IQGlenn W9IQ

                14.3k1943




                14.3k1943






























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