I was hoping someone could clarify 2 questions for me?
1) It is legal to profit from part 15 broadcasts to sell spots to businesses, correct? Then I heard you can not do that above 1700?
2) If I have the rangemaster, what should my target frequency be to get the maximum range? 1610? 1550? I know the actual frequency used will be determined by it's already being in use but if I have options just wondering what the best one to use to achieve maximum and legal range? 1710 is available now.
Theoretically, the higher the frequency, the more efficiency in your antenna. Practically, with a Rangemaster (and other transmitters), I've seen no discernible difference in range between using 1500 thru 1700.
I also believe that you can't use 1710 under the Part 15 rules.
As far as profiting from Part 15 broadcasting, as far as I'm aware, there are no restrictions.
The main Rule we are talking about is 15.219, the one which allows 3-meter antennas and 100mW from 540 to 1700 kHz.
The spectrum from 1710 kHz on up through the shortwave band is regulated by 15.223, which allows part 15 use at much reduced power and other limitations as to bandwidth and other factors.
Artisan is spot on when he says there is little difference observable between 1550 and 1700 kHz, although there may be some small difference in terms of inches or feet, but nothing of any size.
I also believe that the lowest frequency for efficiency is said by PhilB, in the manual for the AMT5000, to be 1350 kHz.
To make the choice I would recommend looking for the highest possible frequency that is quiet day and night and which has no other nearby stations on adjacent frequencies above or below the main channel.
To the first question, regarding earning a profit with a part 15 radio station, it can be done legally by the fact that the FCC Rules have not prohibited doing it.
Many part 15 stations participating in this board (part15.us) are very successfull with commercial operation, and their websites reflect this with many ads posted from local merchants.
For my station I'm considering taking paid infommercials and paid religion.
Yes, it is legal to sell ads on Part 15 stations. I once had Clear Channel Outdoor buy spots on my station to promote a local event. We had an audience not reached by their cluster.
With the rangemaster, your best bet is between 1610 and 1700. 1710 is not allowed, and even if it were, the power level allowed is even more strict.
Best Part 15 coverage I ever got was from a transmitter that is no longer produced - a Cunningham. Running at its lowest power, I still had a listenable signal for 2 and a half miles. One Sunday afternoon I had a listener report hearing it at 4 miles. This was on 1160.
I traded my rangemaster for a Talking House. I ran the rangemaster on 1610 and have the TH on 1610 also.
Look for the clearest signal in the expanded band for best results with the rangemaster.