Watt AM transmitter for the 10 meter band (28MHz) - In
this project, you will make a simple 3-stage low-power broadcast-type circuit, using a crystal oscillator
integrated circuit and an a collector modulated AM oscillator with amplifier. You can connect the circuit to
the an electred microphone or amplified dynamic microphone. Using an electred microphone is shown (in gray)
in the diagram below. (no amplified dynamic microphone has a to low output voltage to work. at least 100mv is
needed). You could also add a LF preamp stage of one transistor to allow connecting a dynamic microphone
directly. You'll see that you can receive the signal through the air with almost any AM radio receiver.
Although the circuits used in radio stations for AM receiving are far more complicated, this nevertheless
gives a basic idea of the concept behind a principle transmitter. Plus it is a lot of fun when you actually
have it working! Remember that transmitting on the 10 meter band you'll need a valid radioamateur license!!.
. . [by Guy Roels ON6MU]
300 MHz AM RF Remote Control System - If you plan to build this project, simply replace the RE-99 receiver & TX-99 transmitter
with the RWS-434 & TWS-434A RF receiver & transmitter modules found HERE. These circuits will work with any
RF transmitter and receiver modules. Due to the huge interest in this project, I have just recently finished
the NEW schematics. The older schematics were scanned and pretty poor quality. These new ones should make it
considerably easier to recognize the parts used for the project. . . . [Copyright Reynolds Electronics]
4 MHz Amplitude Modulated RF Source - A while back I needed an amplitude modulated signal source at 4 MHz. This circuit was
literally thrown together with parts laying on the bench. I built it dead bug style on a piece of copper clad
board. It should work with little or no modification, other thano get it to oscillate, and at higher
frequencies, you might have to reduce the capacitor values a little. Just be. . . [From Dick Cappels'
40 Meter Direct Conversion Receiver - Using the circuit of direct-conversion receiver described here, one can listen to amateur
radio QSO signals in CW as well as in SSB mode in the 40-metreband. The circuit makes use. . . .
40 Meter Popcorn Superhet Receiver - schematic for a no-frills, relatively low-cost CW superhet receiver with a 4. 00 MHz
Intermediate frequency. There is no AGC or RF gain control, however this receiver has good large signal
handling capability. This receiver uses just 6 bipolar transistors and an op amp for reasonable volume into
headphones. Much. . . [Circuit designed by VE7BPO]
40 Meter, 5 Watt QRP Transmitter - As ham operators, we like to broaden our horizons by trying something new. There is nothing
more satisfying about this hobby than building your own transmitter. The circuit in figure 1 is a crystal
controlled CW transmitter with at least 5 watts of power. (The prototype generated 7 ½ watts) This circuit
was built on a Radio Shack universal board (276-168B) and worked extremely well the first time. . . [Radio
Amateur Society of Norwich]
AM transmitter for the 20 meter band (14MHz) - In this
project, you will make a simple low-power broadcast-type circuit, using a crystal oscillator integrated
circuit and an a collector modulated AM oscillator. You can connect the circuit to the an electrec microphone
(pointed out in gray on the diagram) or amplified dynamic microphone (no amplified microphone has a to low
output voltage to work. Approx. 100mv is needed). You could also add a LF preamp stage of one transistor to
allow connecting a dynamic microphone directly. . . . [by Guy Roels ON6MU]
Add-on modulator has
high bandwidth - 09/11/99 EDN Design Idea The simple
circuit in Figure 1 is an add-on modulator that converts the output of a continuous-wave (CW) source to
either an amplitude-modulation (AM) or a suppressed-carrier-modulation (SCM) format. Because the circuit has
unity gain and 50 Ohm input and output impedances, the CW generator's output-level indications remain valid.
The frequency response is flat from 0. 3 to 45 MHz and only 0. 1 dB down at 0. 1 and 60 MHz. . . [by MJ
Salvati, Flushing Communications, Flushing, NY]
AM Broadcast Band
Regenerative Receiver just two transistors! - amateur
radio construction projects. circuit only, no description given. . . . [from Peter Parker's website]
AM DSB Transmitter
for Hams - circuit diagram of simple double side band
suppressed carrier (DSBSC) transmitter for hams. Circuit uses crystal oscillator, crystal can be switched for
multi band operation. . .
AM Farm Radio Power Supply - Prior to the 1950s, many rural areas in the US had no electricity. Many companies sold
battery operated vacuum tube radios for use in these areas, the radios are commonly called Farm Radios. Farm
radios are often available at very reasonable prices and can make a good restoration project. . . [G.
AM FM Simultaneous
Transmitter Using Digital IC - . . . [by ASWINKUMAR
aswinefy2003 @ yahoo.Co.In]
AM Loop Antennas (Bruce Carter) - . . . [by Bruce Carter]
AM Modulator - This circuit uses two signal generators to simulate an Amplitude Modulated RF carrier wave.
The output can be used to simulate the response of LC and tank circuits. . . . [Andy Collison's website]
AM Oscillator - Schematic only, no circuit description. . . [CircuitoZ.net, contact Ruddy]
AM Radio - Schematic only, no circuit description. . . [CircuitoZ.net, contact Ruddy]
AM Receiver - This is a compact three transistor, regenerative receiver with fixed feedback. It is
similar in principle to the ZN414 radio IC which is now replaced by the MK484. The design is simple and
sensitivity and selectivity of the receiver are good. . . . [Design by Andy Collison]
AM Receiver for Aircraft Communications - This receiver is controlled by a Frequency Synthesizer Circuit. The receiver is VERY
stable, low noise-level and easy to build and tune. . . [maxit91 AT hotmail.com]
AM Receiver with Quadrature Mixer - This circuit is for a superheterodyne receiver where the image frequency is suppressed
without the use of an input filter. Instead, it uses two NE (SA) 612 type mixer ICs that each work 90. must
register on this site. . . [Published in Elecktor July/Augu, 2010]
AM to FM converter - . . . [by aswinkumar]
AM Transmitter - The circuit is in two halfs, an audio amplifier and an RF oscillator. The oscillator is
built around Q1 and associated components. The tank circuit L1 and VC1 is tunable from about 500kHz to
1600KHz. . . . [Andy Collison]
AM/FM Radio Frequency
Amplifier for receivers - This 'AM-FM Radio Frequency
Amplifier' is built with only a few components; which makes the project simple and direct. There are no
electrolytic capacitors and the three capacitors used can be ceramic or mylar. You can employ 1/4 watt
resistors or even 1/2 watt resistors which are easier to manage. . . . [braincambre500 AT yahoo.com]
Antenna - This circuit shows an active antenna that
can be used for AM, FM, and shortwave SW. On shortwave band this active antenna is comparable to a20 to30
foot wire antenna. This circuit uses receivers that use untuned wire antennas, such as inexpensive units and
car radios. . .
AM2 circuit - This is the schematic only. . . [quadworld AT reocities.com]
Amplitude Modulation of the AD9850 Direct Digital Synthesizer - AN-423-Analog Device App Note. . .
Am-Receiver for Aircraft Communication
118.250MHz - This receiver is controlled by a
Frequency Synthesizer Circuit. The receiver is VERY stable, low noise-level and easy to build and tune. .
. [maxit91 AT hotmail.com]