The seller makes no representation of any item(s) sold to be fit for a particular purpose and assumes no liability for its use or misuse. It is assumed that the unit(s) will be installed and operated by qualified personnel. The purchaser agrees that the seller shall not be held responsible or liable for any injuries or damages, whether incidental or consequential, associated in any way with the item(s).  Not for sale to, or use by minors.

This is our new, deluxe, PC (Printed Circuit) board version, reproduction kit of the Knight Broadcaster - Amplifier.  The Knight Broadcaster Amplifier is a low power (100mW, Part 15 compliant) AM transmitter.  You can learn more on the Internet if you are unfamiliar with it.

Three tube design, transmits your mono voice or music signal to any standard AM radio receiver using a microphone (not included), or high level inputs.   High level inputs can be from a MP3 player, iPod, iPhone, cassette player, etc..  The kit also functions as a PA (Public Address) style audio amplifier, and has connections you can hook up a loudspeaker too.  The audio input connection is by the included 3.5mm stereo jack, shown mounted on front panel.  Stereo signals are mixed to mono on the board.  A 2-pin screw terminal connector is located on the board for the PA loudspeaker connection.

This version of the kit must be housed and operated in an enclosure, and comes with your choice of a black or gray plastic case.  User must drill holes as necessary for construction.

The kit is electrical equivalent to the original, with several minor changes. Our design includes a brand new, high quality, Triad safety isolation transformer.  Domestic orders will receive a 110VAC primary transformer.  International orders will receive a 110-220V dual primary version.  The selenium rectifier has been replaced with a modern silicon diode. Kit comes with a prewound oscillator coil. Kit uses carbon film resistors.  Kit includes several fixed capacitors for tuning, in place of a costly variable tuning capacitor.  If desired, the user can install a variable or trimmer capacitor (not supplied), for variable frequency adjustment.  Kit uses an external wire antenna, not shown connected in photos. Kit comes complete with all parts as shown.  Design includes thermal protector in case of excess heat generation.  Plastic case is not compromised, even with fan not running.

In order to reduce costs, and improve operation, we have redesigned the circuit to use a less expensive 9AU7 preamplifier tube.  We have also included a switch, to select between one or two sections of the preamplifier tube, to prevent overloading with high level signals, and improve signal to noise ratio.  The pinout of the 9AU7 is the same as the original 12AX7, and the circuit can be easily modified to use that tube if desired. 

NOTE: This kit requires good electrical and mechanical building skills, and is recommended for advanced builders.  Assembled kits can not be returned. 

Some simple mechanical modifications are required, such as cutting the metal potentiometer shaft to the correct length, drilling holes in the plastic cabinet, etc..  Triad isolation transformer may be boxed or unboxed (bulk purchase).  No warranty on vacuum tubes.  Assembled kits can not be returned.

The original manual is supplied as a PDF and file on a CD-R.  An addendum assembly notes file is supplied in RTF format.  Note we do not supply copies of manuals.  Kit must be in original, unbuilt condition for refund.  Original shipping cost not refundable. The kit is only for sale people with experience building and operated line powered devices. The kit must be operated under FCC Part 15 regulations at all times. This unit must only be operated with the supplied line isolation transformer. Not for sale to, or use by minors.  User assumes all liability.