The product from K. Hamilton has coil taps and a "tuning" capacitor.
It should also be noted that the Procaster was certified with a 1 meter ground lead attached in addition to the supplied stock antenna, thus exceeding the 3 meter limit for radiating conductors.
jm
Good Work Everybody
I think we've sold some transmitters here today.
The Procaster antenna as supplied is 14" short of the limit, allowing for up to a 14" ground lead. As the antenna is assembled from aluminum poles that slide inside of each other, length can easily be shortened a bit to allow for a bit more ground lead if you need it.
The complete and current Procaster manual and a bunch of other documentation is readily available at their website https://www.chezradio.com .
Mine has been running rock solid, on frequency and constant power output, for over 5 years now.
TIB
I'm personally getting rather tired of the discussions surrounding Part15.219 (or RSS210) antennas, ground leads, etc. The intent always appears to be negative in nature, and an attempt to discourage current and future Part 15 broadcasters.
If you go to Part 15.219, you'll find the following: "The total length of the transmission line, antenna and ground lead (if used) shall not exceed 3 meters". And that's it. No definition of ground lead, antenna, or even transmission line. The term "radiating" is often placed in these discussions, here and elsewhere, but nowhere is that word found in the rules.
Exactly what constitutes an antenna, a ground lead, or a transmission line, is entirely at the discretion of an FCC inspector.
So, if one were to attach a 14 inch ground wire to a ground on a ProCaster, that would be acceptable according to the rules, as there is no transmission line.
If that ground radiated, it would be up to an FCC inspector (if it got that far) to determine if the ground being used (such as a metal mast) was part of the ground lead, or not. There have been cases where it was, and cases where it wasn't. Generally, the former is associated with abnormally large range being achieved (in the case of KENC, often brought up, they were getting 5+ miles from their billboard mounted transmitters). Combine that with the fact that the KENC operator was purportedly obnoxious and unwilling to listen to the FCC, and you have the receipe for being shut down.
However, that type of case is by far in the minority.
The one good thing that has come out of these discussions is a reiteration of the math that demonstrates that for a ground-mounted Part 15 compliant installation, 1 mile (and maybe a bit more) is achievable. In less RF noisy, rural areas, perhaps more.
I think we can wrap up this with the following observations for those actually interested in doing Part 15 broadcasting.
Use an FCC certified transmitter, particularly if you are not technically oriented. If you are, it is OK to use an uncertified transmitter, as long as you can ensure that you are staying within the 100mw input limit to the final stage of the transmitter, and that "All emissions below 510 kHz or above 1705 kHz shall be attenuated at least 20 dB below the level of the unmodulated carrier".
Ensure that you are not getting excessive range from your transmitter. It is likely that if you stay within that theoretical 1 mile limit, the FCC will never come calling.
It goes without saying that you must never cause interference to existing, licensed services.
If the FCC does show up, be courteous and also be prepared to explain how you attempted to stay within the Part 15 rules. Keep a copy of the rules, and information of what you are doing handy.
It may be that the FCC asks you to make changes to your installation. If they do, agree to do whatever they suggest immediately, and again, keep records.
If you do these simple things, and demonstrate both the knowledge and willingness to be compliant, then I don't think there will be any issues.
And leave those who have no intention of ever doing Part 15 broadcasting to their charts and wordy diatribes. It probably makes them feel important.