Post by Deleted on Jul 13, 2017 19:09:02 GMT
I'm considering starting an Information Service for the Osprey Village area of Pitt Meadows. It consists of one large strata, with mixed businesses, shops & residential.
There are several ways to go to do this. I could apply for an RSS123 license from Industry Canada, which would mean that I could easily cover this area with an appropriate certified transmitter (I picked up a Decade LX-75). There is the issue that the field strength has to be 100uv or less at the area boundaries, and I'm not sure how Industry Canada would allow me to define that area. But I will be investigating that approach.
I could also use either RSS210 (since according to Industry Canada and the CRTC, an Information Service isn't a broadcasting endeavor) or BETS-1, both of which allow a field strength of 100uv/m at 30 meters.
I currently own an RSS210 transmitter, with a wire antenna (an old Landmark, IC certified for that service). The wire is strung up the side of the window in my office on the lower floor of my townhouse.
I've been doing some range testing with that transmitter, using my car radio (of unknown sensitivity, but pretty decent), and a portable Panasonic shortwave receiver of again, unknown sensitivity, but less than that of the car (probably, however, better than most consumer type portables, although that is unknown).
With the portable, I generally can get about 50 meters range (175 feet) of stable signal before it fades out rather abruptly. With the car, I can hear the signal similarly up to about 150 meters (over 300 feet). Both measurements taken from Google Maps.
Now, I moved the transmitter to the third floor of my townhouse, and installed it exactly the same as in my office. The window is the same size, and right above the office window (but maybe 20 feet higher). This gets the antenna above some ground level obstructions (mainly trees), and also just plain adds height.
My range dramatically increased - to about 100 meters for the portable, and 300 meters for the car (I didn't have time to test the car out extensively, as I was mainly interested in the portable results, but the signal was still solid at that range, while the portable's had faded out suddenly).
I'm not going to make any conclusions to these tests right now, as I obviously need to do more, with different radios, but it's obvious that for various reasons, height does have a positive effect on low power FM transmitter range. There's no way that my signal is going to go miles, as some have bandied about, however.
I do know that on Bowen Island, my Decade MS-100, with direct line of sight to a better car radio than the one I have now, and installed on a rooftop at the top of a hill, managed anywhere between 500-1000 meters (but realistically, usable range to most good car radios was 250-500 meters). So my testing so far is in the ball park, at least, with previous experiences.
The biggest problem I'm going to have if I go the BETS-1/RSS210 route is consistent coverage to a portable inside a building at the extreme end of the Osprey Village strata (I'm at the other end, and it's 100-125 meters with an obstruction i.e., the building). However, it's going to be difficult to get the field strength at the strata boundaries down to 100uv if I use more field strength with RSS123, as the shape is a fairly narrow oval, rather than a circle or square. I will also need to obtain a field strength meter - I'm looking to either rent one, or to get a local ham club to help me out (the one I belong to doesn't have one, unfortunately).
Anyway, I just thought I'd report my preliminary findings. I hope I put enough caveats in the description to show that there's a lot more work that has to be done, and a lot more rigor added to the entire process. This was just a 'throw it at the wall and see if it sticks' type test, since there was no way with my office installation that I was going to be able to do what I want to do with RSS210.
There are several ways to go to do this. I could apply for an RSS123 license from Industry Canada, which would mean that I could easily cover this area with an appropriate certified transmitter (I picked up a Decade LX-75). There is the issue that the field strength has to be 100uv or less at the area boundaries, and I'm not sure how Industry Canada would allow me to define that area. But I will be investigating that approach.
I could also use either RSS210 (since according to Industry Canada and the CRTC, an Information Service isn't a broadcasting endeavor) or BETS-1, both of which allow a field strength of 100uv/m at 30 meters.
I currently own an RSS210 transmitter, with a wire antenna (an old Landmark, IC certified for that service). The wire is strung up the side of the window in my office on the lower floor of my townhouse.
I've been doing some range testing with that transmitter, using my car radio (of unknown sensitivity, but pretty decent), and a portable Panasonic shortwave receiver of again, unknown sensitivity, but less than that of the car (probably, however, better than most consumer type portables, although that is unknown).
With the portable, I generally can get about 50 meters range (175 feet) of stable signal before it fades out rather abruptly. With the car, I can hear the signal similarly up to about 150 meters (over 300 feet). Both measurements taken from Google Maps.
Now, I moved the transmitter to the third floor of my townhouse, and installed it exactly the same as in my office. The window is the same size, and right above the office window (but maybe 20 feet higher). This gets the antenna above some ground level obstructions (mainly trees), and also just plain adds height.
My range dramatically increased - to about 100 meters for the portable, and 300 meters for the car (I didn't have time to test the car out extensively, as I was mainly interested in the portable results, but the signal was still solid at that range, while the portable's had faded out suddenly).
I'm not going to make any conclusions to these tests right now, as I obviously need to do more, with different radios, but it's obvious that for various reasons, height does have a positive effect on low power FM transmitter range. There's no way that my signal is going to go miles, as some have bandied about, however.
I do know that on Bowen Island, my Decade MS-100, with direct line of sight to a better car radio than the one I have now, and installed on a rooftop at the top of a hill, managed anywhere between 500-1000 meters (but realistically, usable range to most good car radios was 250-500 meters). So my testing so far is in the ball park, at least, with previous experiences.
The biggest problem I'm going to have if I go the BETS-1/RSS210 route is consistent coverage to a portable inside a building at the extreme end of the Osprey Village strata (I'm at the other end, and it's 100-125 meters with an obstruction i.e., the building). However, it's going to be difficult to get the field strength at the strata boundaries down to 100uv if I use more field strength with RSS123, as the shape is a fairly narrow oval, rather than a circle or square. I will also need to obtain a field strength meter - I'm looking to either rent one, or to get a local ham club to help me out (the one I belong to doesn't have one, unfortunately).
Anyway, I just thought I'd report my preliminary findings. I hope I put enough caveats in the description to show that there's a lot more work that has to be done, and a lot more rigor added to the entire process. This was just a 'throw it at the wall and see if it sticks' type test, since there was no way with my office installation that I was going to be able to do what I want to do with RSS210.
