PLEASE NOTE: AFTER MANY YEARS I MUST RAISE THE PRICE OF MY BROADCASTERS DUE TO INCREASE COST OF THE PARTS THAT I USE IN THEM. The unit can be operated with various sources and produces a clean full range audio sound when connected to a audio line level (even at extremely low levels) or speaker level source. I have built many of these over the years for individuals to use with their antique radios both here in this country and for export to other countries and overseas. The Broadcaster makes it possible for owners to listen to their favorite music or programs wirelessly and is especially usefull for radios that do not have a separate audio input to use.It has two controls: Off/On Volume - to turn the unit on and adjust the level to match the sound source that it is connected to and Tuning - to select a frequency for the radio to receive the signal. It includes an audio cable with two male RCA phono type connectors for mono or stereo sources and can be adapted where necessary and a 9.8 foot antenna wire. The unit has a polarized power cord and power transformer for safety, built from more than 65 new and NOS parts and incorporating four stages - three tube based in operation using a shunt feed Hartley oscillator, modulator, carrier control and output amplifier. I settled on the original design back in the 90's with considerable refinements to provide much cleaner and more effective output power with wideband audio response (not limited to 5Khz) for a crisp alive sound but still have the warmth of sound in tube based operation. The Broadcaster is extremely frequency stable. Once you have set the frequency that you want it will not drift from when first turned on each time and will not drift after having been on for hours or days. There is no interaction between the antenna and the surroundings including people. It can be safely operated 24 hours a day 7 days a week. It does produces a noticeable amount of heat but allowing for normal use with proper ventilation. I began hand building them in the 90's one at the time and all of them essentially the same in looks and operation, performance and durability, the quality of my craftsmanship and a proven design. The Broadcaster is legal to use without a license relating to FCC rules Part 15 in that the transmitter may generate no more than 100 milliwatts (1/10 of 1 watt). Under these FCC rules the transmitter has a limited range on average 40 to 100 feet. The signal received by the radio is tuned in just like tuning in a regular radio station. Using just two controls - one to adjust the volume to the source it is connected to and the other control to select a location (frequency) for the radio to tune in the signal, the unit is very easy to operate and includes easy to follow setup instructions. I have been collecting and restoring electronics for over 50 years. My background in broadcast engineering was life long until retirement. The item "AM BROADCAST TRANSMITTER HEAR YOUR MUSIC ON ANTIQUE AIRLINE PHILCO RCA ZENITH" is in sale since Friday, July 5, 2019. This item is in the category "Collectibles\Radio, Phonograph, TV, Phone\Radios\Tube Radios\1930-49". The seller is "bev815" and is located in Waverly, Virginia. This item can be shipped to North, South, or Latin America, all countries in Europe, Australia.