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Post by thelegacy on Dec 30, 2017 10:03:09 GMT
I was playing around looking at the nouo activity. It seems that there is a little Miss information about frequencies between 30 megahertz and 88 megahertz. Remember the question arised how a certified transmitter can cover 87.7 and 87.9 megahertz. Well apparently there is some new rulings and this nouo clearly states it. Remember that 100 microvolts per meter is about the same transmission strength as the C crane transmitter that Timin bovey tested. It also explains why the Rolls transmitter also has those frequencies. Here is the link so that you can take a look at it for yourself. I think this will clear it up quite nicely. transition.fcc.gov/eb/Orders/2017/DOC-348371A1.html |
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Post by mark on Dec 30, 2017 17:06:08 GMT
Very good find!
You have shown that it is not illegal.
Wonder what the Canadian situation is now you've got me interested.
Mark
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Post by thelegacy on Dec 30, 2017 18:23:39 GMT
I really don't know about Canada. I can surmise that it's going to be very similar in Canada.
This is not really related to FM but no way it is. Back in the day when cordless phones use the 46 megahertz and 49 megahertz band and I had a police scanner I could receive some cordless phones almost a mile away.
My parents were quite intrigued on how you could eavesdrop on their neighbors with a police scanner. One day there was a lady that came in which I didn't know however my mother was saying I work with this woman I know where she lives she's about a mile away. I told her that I couldn't believe that I was actually receiving a signal that far from a little cordless phone on my police scanner which by the way seem to be coming in quite clearly.
The power line affect also seem to affect those frequencies down there. I noticed that even with an inside antenna when the scanner was plugged in I could pick up for quite a long range.
Now here I go again relating this to the FM argument about the 150 foot or 200 foot range. If 100 microvolts per meter at 3 we can be heard for a mile or darn near close to it on certain receivers I still believe that one could be heard for that distance on the FM band. Though most of the time it's not likely but under certain conditions where the signal is not blocked or could be following the power lines for some reason.
More importantly though this does show that transmitting on 87.7 megahertz and 87.9 megahertz is absolutely not illegal the problem is is that it has not been clarified that you are allowed legally to broadcast down there but the power level is slightly less.
Also this might explain about the white space and being able to use those frequencies. But I do surmise that later on down the line something may change where you will be able to operate those frequencies providing that you don't interfere with anything with a greater range. It seems more and more we're seeing a change in the rules that the FCC is governing us with. We see it in these notices of unlawful operation that clearly state that you are legally able to broadcast on those frequencies. So if you have a scoach transmitter or any other type of transmitter that you bought at say Walmart or it is certified and it has those frequencies on it I would not be afraid to use them. But be very cautious that you don't step on anything. Do your homework check out your data sheets and make sure that even know digital signal is being transmitted down there.
Remember the other rule of part 15 and that is as that you shall not cause harmful interference. And if you know that there is a possibility of it then by all means do not operate. That is a good responsibility of any radio hobbyist.
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Post by mark on Dec 30, 2017 22:57:01 GMT
No, in Canada those frequencies are still for TV and other things and no unauthorized transmission can be there unless it's "momentary" as I understand it with RSS-210
BETS-1 is only for the 530-1705 KHZ and 88-105 MHZ
The other BETS categories don't allow unauthorized use of those frequencies.
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Post by thelegacy on Dec 30, 2017 23:47:32 GMT
I do find it interesting that in Canada BETS-1 ends at 105 megahertz. I know that the C.Crane transmitter is not BETS-1 certified for Canada but yet it to ends around 105. I know it doesn't go all the way to 107 Mhz..
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Post by mark on Dec 31, 2017 2:25:49 GMT
BETS-1 says you can only go to 107.5 and Decade's don't tune past that.
But RSS-210 which operates at the same field strength allow to 108(107.9)
The Ccrane isn't certified for Canada at all BETS or RSS-210, only part 15
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Post by Druid Hills Radio on Jan 2, 2018 20:08:11 GMT
I was playing around looking at the nouo activity. It seems that there is a little Miss information about frequencies between 30 megahertz and 88 megahertz. Remember the question arised how a certified transmitter can cover 87.7 and 87.9 megahertz. Well apparently there is some new rulings and this nouo clearly states it. Remember that 100 microvolts per meter is about the same transmission strength as the C crane transmitter that Timin bovey tested. It also explains why the Rolls transmitter also has those frequencies. Here is the link so that you can take a look at it for yourself. I think this will clear it up quite nicely. transition.fcc.gov/eb/Orders/2017/DOC-348371A1.htmlNo not 100% legal. You are correct about the emission level, however the emission type is not permitted. From OET #63: 76-88 MHz Intermittent Control Signals 1,250 µV/m @ 3 m A or Q 15.231 Periodic Transmissions 500 µV/m @ 3 m A or Q 15.231 Non-Residential Perimeter Protection
Systems
100 µV/m
@ 3 m
Q 15.209
This is still an analog TV allocation and as such FM broadcasting by any Part 15 device is not permitted. Sorry. The Q designates the type of detector used to make the measurement. Quasi-peak detectors are used because of repetition rates associated timing circuits typically found in digital devices, not broadcast transmitters. |
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