First, a word from our legal department: For educational purposes only. These kits are offered for the furtherance of one's knowledge regarding radio frequency design and principles. At all times during operation the assembled unit must be connected to a dummy load. Part 15 of the FCC rules prohibits an antenna being used with these units. All responsibilities for the ultimate use of these kits are born solely by the builder and/or operator.

Certain kits are designed to work with each other. For those whose wish to boost the output of their Ramsey FM-10 the 1/2-1 watt amp will work very well for this purpose. The 30 watt amp is designed to be driven by 3-5 watts and works extremely well with the 5 watt transmitter. The 15 watt amplifier is designed to be driven to full power with about 1/2 watt of input power, hence it works very well with the 1/2 watt stereo transmitter or PLL transmitter. If you wish to only boost a 1/2 watt signal to 5-7 watts then choose the 6 watt amplifier kit. An amplifier only increases the output power of a given input signal, it can not produce an FM signal whereas a transmitter or an exciter creates the FM signal at a suitable power level for possible further amplification by an RF amplifier. 1/2-1 Watt PLL Transmitter - $95 Our newest kit. Full digital PLL control locks the frequency and prevents any drift from happening. Will easily drive the 6-8, 10-15, and 20-24 watt amplifier kits. Easy to assemble and a major improvement over the Panaxis PLL kit. If you have one of our 5 watt transmitter kits, they can be modified to be driven by the PLL transmitter. Full instructions are provided for this modification.

---

• 1/2 - 1 watt Stereo Broadcast Transmitter - $50
  A vast improvement over the Ramsey FM-10. It uses the BA1404 IC as a stereo modulator only to modulate a FET vfo, buffer and amp chain. Better audio input filtering and bypassing. IC voltage regulation for the 2.5 volt supply for the BA1404. A very rugged output stage and collector voltage bypassing make this unit stand out from all other transmitter designs using the BA1404 chip. Requires 12 volts DC

• 5 Watt FM Transmitter- $55
  An improved version of the Panaxis 5 watt design with a much more rugged output transistor capable of producing 5-6 watts. This is a very good basic unit that is very compact, fits into a 4 x 6 inch enclosure (available punched and drilled). Frequency stability is maintained by a well designed oscillator section. It is a mono unit that accepts line level input (i.e. an audio signal from a tape deck, mixer, etc.). A fine frequency adjustment control allows for easy adjustment of operating frequency. To increase power of this transmitter use the 30 watt amplifier. Both will fit into a 7 x 7 inch enclosure (available punched and drilled). Requires 12 to 14 volts DC at 3/4 to 1 amp for operation.

• 6 watt RF Amplifier - $30
  Uses the same output transistor as above. It is designed to boost low wattage transmitters to a bit higher output power and will produce up to 8 watts of output power. A very small and compact circuit measuring 3 x 1 1/2 inches for 1/2 watt input drive. Easy, quick assembly. Requires 12-14 volts DC at 3/4 to 1 amp for operation.

• 15 watt RF Amplifier - $50
  Uses a very high gain (14dB, power gain of at least 25X) RF transistor to boost a 1/2 watt input to 15 watts. Perfect for boosting the 1/2 stereo transmitter to 15 watts. Measures 2 1/2 by 5 inches and fits into a 4 x 6 enclosure (available punched and drilled). Includes heat sink. Easy, point to point surface mount assembly. Requires 12-14 volts at 2 amps for operation.

• 20 -24 watt RF amplifier - $95
  $95 might sound a bit steep, but for those who do not wish to do an extensive amount of soldering and tuning, this is kit is for you. It uses a broad band high gain, RF power module which will put out a 20-24 watt signal for only a 100 to 200 miliwatt input. Kit requires less than 20 solder connections to complete, including a 5 element filter. Since the module is broad band from 88 to 108 MHz no tuning is required, plug and play as they say. Requires 12-14 volts at 3 to 4 amps.

• 25-30 watt RF Amplifier - $60
  Will produce full power with an input drive of 3-5 watts. This unit works very well with the 5 watt transmitter kit. In fact, next to the 5 watt kit, it is our most popular item. Fits a 4 x 6 inch enclosure (available punched and drilled). Easy point to point surface mount assembly. Includes heat sink. Requires 12-14 volts DC at 4-5 amps for operation.

• 1/2 to 1 watt Amplifier - $25
  1/2 to 1 watt output for an input power of 10 mw. Great for boosting lower power VFOs and low power Ramsey FM-10 type kits. Very compact size, 3 1/2 X 1 1/2 inches. An optional transistor can be substituted to take the power up to 1 1/2 watts, add $5 for this option.

• Output Filter Kit - $8.00
  A seven element low pass filter, composed of 4 coils and 3 capacitors, to flatten those harmonics. Specify cutoff frequency desired, 94 MHz, 100 MHz, 104 MHz, 108 MHz. The cutoff should be about 2 to 4 MHz above the frequency the transmitter is set for. Please use a filter on any transmitter you to use to avoid possible interference with other services.

• 15 Watt Dummy Load Kit - $10.00
  Essential for tuning up and testing transmitters and amplifiers. Will handle 15 watts without any strain, higher powers for a briefer period of time (i.e. shut down when it gets rather hot). Presents a uniform 50 ohm impedance to the transmitter.

• 25 Watt Dummy Load Kit - $20
  As above, use this with the 30 watt kit for testing and loading purposes. Uses a single, film non-inductive resistor

• 50 Watt Dummy Load Kit - $35
  Same design as the 25 watt unit, use this if you plan on running the 30 watt unit for an extended period of time with a dummy load.

• 100 Watt Dummy Load Kit - $50
  Same design as the 25 & 50 watt units. Uses 2 film resistors.

• Stereo Generator Only - $30
  Actually 1/2 of the above the stereo transmitter, will allow one to broadcast in stereo using the 5 watt transmitter with a very minor modification.

  ---

  HIGH POWER AMPS - USE WITH CAUTION

  ---

• 75 Watt Amplifier - $175
  Requires 28 volts DC (two car batteries in series or 28 volt DC power supply). Point to point surface mount construction. Easy assembly, includes heat sink. Amplifier measures 6 3/4 x 3 3/4 inches. Only 5 watts input power needed to drive to full power.

• 125 Watt Amplifier - $225
  Requires 28 volts DC (two car batteries in series or 28 volt DC power supply). Point to point surface mount construction. Easy assembly, includes heat sink. Amplifier measures 6 3/4 x 3 3/4 inches. Use a power FET RF transistor that requires only 3-5 watts of input power for 125 watts output.

  ---

  ANTENNA KITS

  ---

  These are partial kits, just go to your local plumbing supply or hardware store for the copper pipe and/or wire needed for completion. Full construction diagrams and instructions included.

• J-Pole - $20
  Metal box drilled with SO239 connector, tuning cap and tubing clamps. This one is know as the "electricians special" since it uses mostly electric hardware in its construction. Works very well for urban areas. No soldering of copper pipe required for assembly. Can be adjusted for operation over the entire FM band.

• Slim Jim - $15
  SO239 connector and clamps. Works very well for urban areas where a powerful horizontal pattern is needed. If used at too great of height, an area surrounding the antenna will be skipped over due to its low angle of radiation. Even at a height of only about 12 feet mounted on a traffic sign pole this antenna was able send a 5 watt signal 2-3 miles. Requires soldering of copper pipe. Can be placed inside a 6" piece of black plastic pipe for concealment. Provides a gain of 2-3.

• Dipole - $20
  Plastic box, SO239 and clamps. Easy and quick design. Can be concealed by placing inside a 4" piece of black plastic pipe.

• 5/8 Ground Plane - $30
  All necessary parts except copper element and ground radials. This is a great design and works extremely well. It is very portable and will boost the power by a factor of 2 to 4.

  ---

  POWER SUPPLIES

  ---

  Unless you are planning on operating from a 12 volt lead acid battery or from the lighter socket in a vehicle you will need an AC operated DC power supply. Wall adapter units can not used. We have the following units available.

• 2.5 Amp 13.8 V DC power supply - $29
  Use this to power either the 1/2 watt transmitter or 5 watt transmitter or the 1/2 watt stereo unit in combination with the 6 watt amplifier.

• 4.5 Amp 13.8 V DC power - $39
  Use this to power the stereo transmitter in combination with the 15 watt amplifier.

• 12 Amp 13.8 V DC power supply - $65
  Use this to power the 5 watt transmitter in combination with the 30 watt amplifier

  ---

  METERS

  ---

• Power & SWR Meters
  These are essential to the proper tuning and setting up of both transmitters and antennas. An antenna has to be fine tuned so that it accepts the full power of the transmitter and reflects the lowest amount possible back, that ratio of forward power to reflected power is know as the standing wave ratio (SWR). The various stages of both transmitters and amplifiers have adjustable capacitors which are used to tune the unit to the frequency of operation. A power meter allows you to see the effect of these adjustments on the power level and to set everything at an optimum level.

• Economy Power/SWR meter - $35
  A compact in-line unit that works up to a frequency range of 150 MHz.

• High Quality Daiwa Meter - $100
  A dual cross needle meter that shows both forward and reflected power on the same meter face. Makes tuning up very easy, no need to switch back and forth between these two functions. Compact design with 12 volt connection for lighting the meter face.

  ---

  FREQUENCY COUNTER

  ---

  To accurately maintain your operating frequency a digital frequency counter is highly recommended. A digital tuner with signal strength indication can be used as a substitute. We have a frequency counter available for $80.00

  ---

  COAXIAL CABLES

  ---

  A coaxial cable is a special type of wiring that has an inner conductor surrounded by an insulating plastic sheath which is covered by a braid of copper wire that is then covered by a plastic jacket. The 75 ohm video cable used in home TV applications is one type of coaxial cable. For most RF purposes, 50 ohm cable is used. Quite a number of 50 ohm coaxial cables are available ranging from the rather small to cables over 1" in diameter. Regardless of the type, all such cables exhibit a loss that increases with frequency of operation and the length of the cable. For most purposes we will concern ourselves with RG8 and RG8x (mini version of RG8). In very short runs RG58 can be used, but we prefer RG8x due to its lower loss and ability to stand a bit more abuse. RG8 has the lowest loss of the group. Under no circumstances should the cables be twisted, kinked or crushed, this will cause major problems. We supply both RG8X and RG8 in the following lengths. Each end is terminated with a PL259 plug. RG8X: 25 feet - $15, 50 feet - $25, 75 feet- $35, 100 feet - $40 RG8: 50 feet - $32, 75 feet - $42, 100 feet - $52

  ---

  ENCLOSURES

  ---

• 4 x 6 aluminum chassis punched and drilled for 5 watt xmtr, 15 watt amplifier or 30 watt amplifier - $18

• 7 x 7 aluminum chassis punched and drilled for 1/2 watt stereo transmitter or 5 & 30 combo or PLL 1/2 watt. - $25

• The Brick enclosure - $30
  Combined heat sink and enclosure, will support a 1/2 or 5 watt transmitter and any of the booster amplifiers up to 35 watts.

  ---

  VARIOUS & SUNDRY ITEMS

  ---

• Tweak stick - $2.50
  Essential to tuning transmitters and amplifiers. Non-conductive body with tiny metal blade at end. In tuning these transmitters and amplifiers a metal screwdriver will cause false tuning to happen due to the interactive effects of the metal and the holder of the screwdriver with the circuit. A plastic TV tuning tool kit can be found at Radio Shack as well.

  ---

  NEW ITEMS

  ---

• Stereo Audio Processor & Mixer
  A combined stereo generator, limiter and audio mixer 1-5 Watt AM & SW Transmitter kit with companion 25-50 watt amplifier kit 1-5 watt UHF TV transmitter kit with 15 & 50 watt amplifier kits

Proceeds from the sales of these kits go to the furtherance of micro power broadcasting, bringing a voice of empowerment to every community. Please add $3.00 for handling and shipping for each kit. $5.00 for the 2.5 & 4.5 amp power supply and $10.00 for the 12 amp power supply. Add $2.00 for UPS 3 day services. COD orders add $5.00. Air mail to other countries, $5.00 per kit.

Return to Micro-Broadcaster's Home.