AM (Amplitude Modulation) Circuits

All contribution to this page are most welcome

Links to electronic circuits, electronic schematics, designs for engineers, hobbyists, students & inventors:

4 MHz Amplitude Modulated RF Source -  A while back I needed an aplitude 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....(schematic / circuit added 6/07) 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-metre band. The circuit makes use…. 40 Meter Popcorn Superhet Receiver -  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]

Add on AM Modulator has High-Bandwidth -  09/11/98 EDN-Design Ideas  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....file has many circuits, scoll to find this one.... [Design Idea 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.. (added 9/04)

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. Forrest Cook]

AM FM Simultaneous Transmitter Using Digital IC  -  (electronic design idea added 09/08)

AM Loop Antennas (Bruce Carter) -  (circuit added 9/04)

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….(electronic design added 6/07)

AM Oscillator -  Schematic only, no circuit description

AM Radio -  Schematic only, no circuit description

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…

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/August 2010]

AM to FM converter -  ….(Circuit design added 08/08) [Site is underconstruction right now]

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/SW Active 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....(added 4/02)

AM2 circuit -  (circuit / schematic design added 6/06)

Amplitude Modulation of the AD9850 Direct Digital Synthesizer -  AN-423-Analog Device Application Notes  (app note added 6/06)

Am-Receiver for Aircraft Communication 118.250MHz -  (electronic circuit added 4/05)