I wonder if they are aware they can run higher power levels under the Campus rule?
For educational institutes, the FCC does not restrict the antenna height or power, but places limits on the field strength at the perimeter of the property.
Unless of course the Rangemaster is already making it...
Few people realize how low the field strength limits for 15.221 (and also 15.209) really are. They are too low to be measured by a standard field strength meter. LPB dealt with the field strength meter problem by making the measurement at half of the specified distance. Unfortunately, this does not work. Standard MF field strength meters actually measure the magnetic field strength, although the readout is in electric field strength units. This is okay in the far field, because there is a direct proportionality between the magnetic and electric field strengths. However, in the near field, no such proportionality exists.
Even if the field strength could be measured, the campus rules are an advantage over the 15.219 rules only if the campus is several tens of square miles in area. 15.219 rules have to be used on a small campus.
Obviously a $10 FSM wouldn't wiggle.
24uv for 1000 kHz (24,000/f kHz) 30 meters beyond the boundary of the campus, that's measurable. The Ztechnology FSM goes down to 3.2 uv/mtr.
I suppose if it's a one building school house on a city block, 15.219 would win if they are trying to broadcast beyond the campus boundary. According to their coverage map, they get a useable range of about 600 feet from the station.
If the campus is as big as some of the local colleges here, that 24 uv/mtr would certainly amount to a fair signal where the concentration of buildings are centrally located.
Here is a LINK with some good info about how to use a FSM.
The problem is not the sensitivity of the FSM in a shielded room, but the atmospheric noise out in the field, where the actual measurements are made. The atmospheric noise in the AM BCB in an urban environment is at least 20 dB higher than the 15.221 and the 15.209 limits (which are not exactly the same).
An LPB application note available on this web site addresses the difficulty with obtaining field strength measurements using a standard field strength meter (costing lots of bucks) legal for verifying compliance with the rules. They advise moving the field strength meter closer to the source. The application note says that the FCC agrees with LPB's approach, but it is nevertheless not correct.
The FCC requires all field strength measurements below 30 MHz for verification purposes to be made by measuring the magnetic field strength, not the electric field strength. The specifications are in electric field strength, however. In the far field, the electric field strength in uV/m is 377 times the magnetic field strength in uA/m. FSMs that measure magnetic field strength are calibrated in electric field stength in the far field. However, in the near field, where LPB recommends placing the meter, there is no constant of proportionality between the electric and magnetic field strengths. Thus, the LPB method will not work.
It is an interesting article, great effort and a nice outcome.
Tedious, repetitive posts about minutia like the differences between various statutes relative to low power radio serve no one, insult the intelligence of our visitors and greatly devalue the otherwise generally good discussions here.
If the school makes a good faith effort at compliance and fails to meet FCC guidelines then I'm sure the FCC and the school can work that out.
Hysterical hypothetical hyperbole offered as "informing people" serves only to confuse and discourage and it really needs to stop. Irrespective of the passionate tomes written all over the web on these issues, I have yet to see an FCC enforcement action based on the positions taken in these discussions.
So knock it off.
Gosh, that made it hard to follow up on Ermi's good point that even though the FSM can measure it, there's simply too much noise to do so.
I forget who followed up on this but there is a recent post here regarding the 13.560 mHz band whereby field strength compliance is estimated by verifying the power into a dummy load and based on antenna/feedline gain/loss and path loss the field strength is predicted. In an oversimplified way, this sounds like modeling.
Perhaps you could move all of this to a new thread regarding the FCC allowing "modeling" whereby a predicted field strength at a known distance based on system efficiency is allowed in place of actual field strength measurments. That would end the reason to bring up the discussions regarding field strength compliance that can't be measured in the real world. We could simply calculate it.
Ermi could probably follow up with a math primer using "best guess" values for unknowns like ground resistance and antenna efficiency to predict the outcome. Some clever person has probably written a simple shareware program to do this.
I agree this was an interesting article with a nice outcome and that tedious, repetitive posts about minutia should be censored.
For a moment I thought that I was [mod. edit...someone else] and I had just posted about ground leads. But seriously, folks:
We have this thread crossed with the 13.56 MHz shortwave thread, but the "modeling" issue was raised here. Even if modeling is not accepted as a valid method of verification by the FCC, if we are conservative and allow a big safety margin, we won't exceed the maximum field strength. There won't be a violation if the field strength limit is not exceeded. There is, of course, a risk because we are responsible for not exceeding the field strength limit in our system.
I just used Google advanced search to look for any enforcement actions in the 13.xx MHz or 22 meter band from the enforcement bureau at www.fcc.gov/eb/
Couldn't find even one.
That doesn't mean that there haven't been any or that an experimenter wouldn't get cited.
It also doesn't mean we can disregard the rules.
But, it is encouraging
Positively so, in fact.
The Saint Leo University station is running 100 milliwatts.