Vectronics VEC-1290K Manual - page 20

VEC-1290K Instruction Manual

AM Radio Transmitter

Getting the most range: The transmitter antenna system is most efficient at the

higher frequencies. The new expanded AM broadcast band between 1610 and

1710 kHz is still relatively free of new station assignments. Likewise, many

VEC-1290K's will make it down to as low as 530 kHz, a relatively quiet

frequency in most areas.

Try to locate the VEC-1290K transmitter in area that is free of metal support

structures. Remember that the VEC-1290K may be remotely located; use

shielded audio cable to run between the transmitter audio input back to the

"station" location. Another "trick" you may try is attaching a good ground to

the transmitter cabinet. This will improve the antenna radiation efficiency.

Always run the six-foot antenna wire in a straight line, never coiled or zig-

zagged.

Understanding the FCC rules:

Federal Communication Commission (FCC) rules and regulations governing

unlicensed AM broadcast transmitters are complicated and technical. Devices

such as the VEC-1290K AM transmitter are covered under Part 15 of the FCC

rules and regulations.

Part 15 rules permit a maximum field strength of 24000/fkH

z

 uV-per-meter at

30 meters, between 510 kHz and 1710 kHz. The rules also permit a 100-mW

transmitter with a ten-foot antenna, including the feedline. In order to meet Part

15 regulations, the transmitter output must be kept below 2 volts rms when

using a 50-ohm antenna. The high-impedance antenna and power level of the

VEC-1290K meet FCC Part 15 requirements.

Your responsibilities under Part 15. Unlicensed devices operating under Part

15 must not cause interference, and must accept interference as a part of their

operation. What does this mean in plain English? If your station is causing

interference to the reception of a licensed broadcast station in your neighbors'

radios, you are in violation of FCC rules and are operating illegally.

Either

operation must be suspended, or a new clear frequency found.

If

broadcast stations are interfering with your broadcasts, this is something you

must accept being a micro-broadcaster under FCC Part 15 regulations.

.

Here are some guidelines to

1. Identify your station regularly, stating your location and purpose. Do not

make up FCC call letters! You can use an ID along the lines of "This is

Radio 910, operating from New York City".

2. Never transmit false distress signals!

3. Avoid profanity or indecency.