everything looks good on paper but once you put RF in the real universe it tends to do strange unpredictable things especially at Medium Wave which is why commercial stations have monitoring points they have to check yearly.
I agree with Rich. Pls reconsider.
But it appears that Rich is calling MLR a liar.
Is that what you agree with?
I personally don't have any heads on my wall 🙂
I too am not a big fan of a simulation, and computer simulations particularly. However, they give you a baseline of what to expect and as always real world conditions will vary.
Especially with power this low, the variables from one transmitter/location to another are HUGE. But too are the variables between radio sets used to determine coverage, signal strength or readability.
This is why an actual field strength meter is useful. They don't HAVE to cost thousands. Almost certainly hundreds.
At the very least a variety of radios at given test points and a good idea of actual distance determined on a map not an odometer are best.
I have done tests of my coverage twice 11 months apart each time stopping at the same 40+ locations, mapped, and each time using 4 different radios and a fiield strength meter. Coverage each date out was virtually identical.
Your test is certainly not worthless. You have a good idea of coverage potential. And a baseline for further testing.
Tim in Bovey
I agree with his request for MLR to reconsider going into a disappearing act.
The problem with range testing is that, as has been pointed out, there are any number of factors that can affect it, including sensitivity of the receiver, receiving antenna, interference, obstructions, topography, etc. Never mind installation paramaters.
A theoretical field strength doesn't necessarily translate into range, given local conditions.
I don't believe that just because Person A gets 1 mile range, say, on his car radio, that Person B will get the same range, even with the same type of car and radio.
What you have to do is to experiment yourself to determine the range YOU'RE going to get, in your situation.
MLR duly reported what he got on his Rangemaster and he also reported what his installation looked like (which is better than some - I really am from Missouri and don't tend to believe reported ranges - or at least their legality - without that detailed information).
I thank MLR for his efforts, and can understand his frustration when his findings are questioned by those who aren't actually doing Part 15 radio.
The whole idea of experimentation is to get real results, not simulated ones. So...let's see. On one hand, we have someone broadcasting with Part 15 equipment, and on the other hand, someone else who is sitting in front of their computer, typing into a computer program. Who do you take more seriously?
I believe that there is a time and place for simulation and theoretical discussion. But perhaps not here, in this instance. The effort could have been better directed towards explaining what was observed if there were concerns, rather than questioning the results (even obliquely).
MLR knows what he's done, and how he did it. I'd just ignore the superfluous comments.
IT is not my nature to ever question results posted from Part 15 operators. In fact I think the fact that someone has chosen to pursue Part 15 radio is a mark of honesty because Part 15 is legal.
If someone is broadcasting illegally, they'd get a transmitter capable of many watts and an antenna way higher than 10-feet, and would post on a pirate website.
To have a man who is NOT a practitioner of Part 15 activity proclaim, in essence, "My fabricated findings are perfectly true and therefore your claimed results cannot be true (therefore a lie)," is annoying to me and as we see drove a Member away.
The fabricated engineering data could be useful information if presented unjudgementally, offered for comparison with real-world results.
I join WDCX and everyone in asking MLR to continue posting here.
The fabricated engineering data could be useful information if presented unjudgementally, offered for comparison with real-world results.
Note that post 15 of this thread does include a comparison of real-world, measured fields taken by a consulting engineer with calculated (not fabricated) fields for the same physical system.
Are you believing that it was presented in a judgmental manner? If so please elaborate. Thanks.
I got to thinking about the NEC Plotting software that is used from time to time to discredit part 15 experience.
All at once I realized the probabilty that the NEC software is not accurate at the micro power range of Part 15, as the software is designed for typical high power RF calculations.
The term "perfect" would then not apply, unless a range of error were stated, i.e., accurate to within +- 60%, or whatever it would be.
All at once I realized the probabilty that the NEC software is not accurate at the micro power range of Part 15, as the software is designed for typical high power RF calculations.
NEC is not designed only for calculation of "high power" antenna/transmit systems.
The only dependence of NEC on r-f power is the field intensity that power produces when applied to that antenna -- which also is true for real-world systems.
Hence the 50/50 prediction curves. 🙂
apply to VHF/UHF broadcast signals, though, not to groundwave AM broadcast signals.
I said.
Saying "NEC is not designed only for calculation of "high power" antenna/transmit systems." does not make it true.
My suspecting inaccuracy of NEC software does not make it untrue.
As I said, I don't believe it.
What I do believe is that there is a reason for incessantly finding in the negative against the hobby activities of a small minority.
Righteous rule disorder.
My suspecting inaccuracy of NEC software does not make it untrue
NEC is very accurate. I know first hand where the FCC has accepted data based on NEC for site calulations.