Looking at Industry Canada specs:
A2.8 Band 88–108 MHz
The field strength shall not exceed 250 microvolts/m measured at 3 metres with an average meter. Any type of modulation (and carrier frequencies within the band 88–108 MHz) may be used for this category.
The occupied bandwidth shall not exceed 200 kHz.
Outside the 200 kHz band (as well as outside the 88–108 MHz band), the general field strength limits listed in RSS-Gen apply.
If the audio input signal is audio and the transmitter is frequency modulated, compliance with the above requirements shall be demonstrated by modulating the transmitter with a 2.5 kHz tone at a level 16 dBhigher than that required to produce a frequency deviation of 75 kHz, or 50 % of the manufacturer's rated deviation, whichever is less.
I have been tinking it was 1,000 uV/M @ 3 meters. Did I miss something?
That's because in Canada, there are 2 sets of rules for unlicensed intentional radiators. You are quoting from RSS210, which to all intents and purposes, identical to the FCC Part 15. RSS210 is to be used for all purposes EXCEPT FOR BROADCASTING. It states this quite clearly in the document, I believe at the beginning.
If you are broadcasting, which is what most of us here do, then you have to use the BETS rules. I believe the reason for this is that we have an extra regulatory body - the CRTC or Canadian Radio-Television & Telecommunications Commision. They are essentially responsible for the content of broadcasting. Licensed radio stations need both an Industry Canada license for the technical aspects of their equipment, and a CRTC license for the content (which is also effectively their business plan).
The CRTC waives the requirement for one of their licenses if broadcasters follow the BETS rules (on either the AM or FM bands) and also meet several other criteria, including following their general code of conduct, no political discussions, you can't have more than one transmitter operating from the same source, etc. And, of course, if you follow BETS, you also don't need an Industry Canada license.
It is in BETS that the FM requirement for a field strength of no more than 1000uv/m at 3 meters is found. Otherwise, the technical requirements are the same as in RSS210. The story is different again for AM in BETS - they define a maximum field strength of 2500uv/m at 3 meters and there is NO 100mw input to the final stage rule. Otherwise, again, the technical requirements are the same as in RSS210.
There is one final difference. You cannot get a BETS certified transmitter. If Industry Canada visits to inspect your site, you must demonstrate to them that you meet the BETS guidelines. If you are using an RSS210 certified transmitter, that pretty much covers it other than showing that you meet the required field strength for the band you're using.
So, technically, if you are broadcasting in Canada on the AM band, you cannot use the ProCaster or any other such RSS210 certified transmitters which operate at a power level of 100mw to the final stage, at least legally, unless you tune them down to meet the BETS AM field strength rules (as it has been stated here in this Forum in the past, those field strength are just barely above noise levels, rendering unlicensed AM broadcasting in Canada moot). That being said, I've never seen or read anything about Industry Canada or the CRTC stepping in and shutting down such a station.
Wow. I did a serach on BETS and all I could come up with was betting in Canada. 🙂 Thanks for your explanation.
BETS-1 is the general document. There's also BETS-5 & BETS-6 which contains specifics for AM and FM micro broadcasting.
Thanks again for the claification.
Based on Tim's tests with field strength we can see that only on paper is Canada's rule 1000uV/m@3meters(FM). The BETS-1 is based on 30 meters, not 3 meters and the amount the signal lessens as you go away from the transmitter is logarithmic. Tim's test results showed that about 2500uV/m@3meters is needed to produce a field strength of 100uV/m@30meters(roughly) which is Canada's regulation.
We now know that 100uV/m@30meters does not equal 1000uV/m@3meters.
So it can be said that Canada is allowed about 10 times what the USA is allowed.(10 times 250uV/m=2500uV/m)
Mark
... So it can be said that Canada is allowed about 10 times what the USA is allowed.(10 times 250uV/m=2500uV/m)
Unfortunately the relationship of those fields is not a simple one, that can be generalized.
The field at 30 meters is much less a function of the field at 3 meters than it is of the heights of the radiation centers of the transmit and receive antennas, the radiation patterns of the two antennas, earth conductivity, and reflections/obstructions from objects along the propagation path.
For example, the field at 3 meters horizontally and 2.5 meters above the earth in the graphic linked below is only about 1.16X greater than the field at 30 meters and 2.5 meters above the earth.
The field at 3 meters horizontally and 5 meters above the earth is about 5X greater than the field at 30 meters, 5 meters above the earth.
The ratios above are valid only for the conditions in that NEC model, and can vary considerably for other configurations.
http://postimg.org/image/52pnv7ujt/
To save time loading the graphic I linked in my last post:
Appreciate your knowledge in this and I stand corrected. Yes there's many variables but we can agree that Canada's rule is not 1000uV/m@3meters which is the point I was making.
Tim's tests were done at 7 ft above ground, no obstacles, over grass,flat ground and his reading with the CM-10 was 3100uV/m@3meters and when he walked 30 meters back the reading was(if I remember right), 270uV/m ?
So I just took that ratio and figured the field strength at 3 meters to get 100uV/m at 30 meters in that paticular setting.
Mark
'm not sure I understand the graph. But are you trying to say that your allowed 2500 uV/m at 3 meters to get the equivalent of 100 uV/m at 30 meters? And if so then the Decade was not that much over Canada's allowance. Maybe this is what we need to ask for. Like I said I don't understand the graph all that well and I'm trying to analyze all of this. Pretty cool stuff. Lets keep tabs on this as well as what may happen with 87.9 Mhz. Both together can help us get more power for FM.
Yes...I am saying that in Tim's particular setting where the measurement was done as per the meter instructions 2500uV/m at 3 meters would be needed to get 100uV/m at 30 meters.
He did the measurement with the CM-10 at 3 meters and 30 meters.
To get Canada's allowed field strength you need more than 1000uV/m at 3 meters.
Even Rich's posts show this.
Canada's rule is based on 30 meters only(BETS-1)
Mark