The transmitter needs to be properly grounded (safety ground). See this paper. Connect the binding post on the outside of the transmitter (ground) to a suitable ground.  Sometimes you can get away with using the electrical ground of a building for ground, often it will not work at ALL!    See this link also.  If you find that you are not getting a sharp peak in voltage when you tune the cap tune then you probably are using an unacceptable ground (see troubleshooting document). This ground could also prove to be a bad lightning ground also. See the hints page elsewhere for an example how to find a good ground. Do not connect in any way to Gas line pipes!!

The FCC Part 15 regulations governing this device are as follows:

Section 15.219 Operation in the band 510 - 1705 kHz.(a) The total input power to the final radio frequency stage (exclusive of filament or heaterpower) shall not exceed 100 milliwatts.
(b) The total length of the transmission line, antenna and ground lead (if used) shall not exceed 3meters.
(c) All emissions below 510 kHz or above 1705 kHz shall be attenuated at least 20 dB below thelevel of the unmodulated carrier. Determination of compliance with the 20 dB attenuationspecificationmay be based on measurements at the intentional radiator's antenna output terminal unless theintentionalradiator uses a permanently attached antenna, in which case compliance shall be demonstrated bymeasuring the radiated emissions.

Groundplanes:

A good ground plane can help your signal. All you need is a solid or wire mesh plane in the dirt below the transmitter. The radius of your ground plane should be about equal to the distance from the ground plane to the tip of your antenna.

 The inner circle of #4 wire should be about a foot in diameter, place around the pole that mounts the transmitter, laying flat, perpendicular to the pole. The #12 wire spokes should be soldered to the #4 wire ring with electrical solder. The wire going to the transmitter can be #10 or #12, or larger.

Avoid Placing your ground rod to close to your house or building. The ground rod needs to be in good dirt away from the sand/gravel foundation fill of the structure. You can place the ground rod 10-20 feet away from the building and bury the wire (preferably un insulated) a few inches below the ground. What works well is to use a flat blade shovel to create a "trench" the the wire can be laid into. Just insert the shovel into the dirt a few inches and rock it back and forth creating a trench. This way the wire can be installed without digging. Two ground rods, a 4 foot right at the building for anchor and lightning protection drain with another 8 foot rod 10-20 feet away into the yard for performance can be a good system. The rod that is in the yard can be totally buried so it doesn't interfere with traffic, lawn mowing, ect. Remember, all connections must be soldered, or bright and shiny and the tightly clamped. What you are doing is making an electrical connection with the earth, the more copper / dirt contact the better. The wire coming from the transmitter needs to be locked down (mounted) so that it doesn't move. The most common range problem is with the ground, either a bad connection, or the ground isn't good. If the ground rod has been put into sand or gravel that will result in bad performance. You want the ground rod into good loamy soil, real dirt, the moister the better. See this e-mail for further information