AM/FM Transmitter schematics from simple to hard..

[Kage]

Schematics Section

Here is the forums area for posting interesting radio transmitter and exciter circuits from simple to complex including
other various circuits dedicated to this subject.

This thread will be updated periodically with more schematics over time.

If you have a schematic or project of your own feel welcome to post a link/picture here.
If necessary you can email me your schematic and I can host it for you.

Last update on: Jan 11, 2014.


Most basic FM transmitters/bugs you could build aka-"toys"

Simple 2 transistor (mod/osc) FM bug type transmitter...


Simple all in one BA1404 IC transmitterfor Part 15 FM stereo broadcasting...
(Note: This IC is no longer being produced and is of low quality anyways, but is okay for very simple yardcasting, also
uses a tunable oscillator so is not very stable for newer radio receivers to lock onto, but is a good learning project)


Simple all in one BH1417 IC transmitter (internal PLL for stability) for Part 15 FM stereo broadcasting...

www.electroschematics.com/55/stereo-pll-fm-transmitter-bh1417/


More complex FM transmitters with higher power

500MW (1/2 watt) FM bug transmitter by Paul K. Sherby...

www.zen22142.zen.co.uk/Circuits/rf/4txtr.htm

1 Watt RF tube amplifier for Ramsey FM10 kit designed by F. Nachbaur...
(Note: I do not recommend ever amplifying the BA1404 used in an FM10 kit, the chip is a terrible harmonic and spur producer!)


2.5 watt RF amplifier for FM broadcast band


4 Watt FM transmitter by smartkit...

Part list and details...
www.electronics-lab.com/projects/rf/001/index.html

5 Watt FM Stereo transmitter using BA1404 chip as stereo generator, PLL circuit for stability. Great design...


7 Watt 2SC1971 FM PA amplifier


10 Watt FM transmitter using single tube...
(Note: This is just for fun, you should never run an oscillator at that power to an antenna without buffering for stabilities sake)


10 Watt FM PA amplifier, needs 1 watt input...



FM Stereo MPX Circuits

Stereo Encoder MPX to turn your Mono rigs into Stereo using the all too popular BA1404..


As simple as you can make using common logic chips and a RC oscillator to create the clock signals but not for professional setups..

Link to site.. www.electroschematics.com/325/stereo-encoder-high-separation/

Higher quality design using common logic IC chips but more complex to design..


Good quality MPX encoder using very common to find 455kHz ceramic resonator for pilot stability that is almost as good as quartz crystal controlled. Really cost effective and makes life easier for those hard to find quartz crystal designs...
(note: 18kHz must be a mistake on their schematic, I believe it should read 19kHz, but the design is the same otherwise)


Very good design that yours truly used as a basis to learn from using common ICs with excellent stereo separation and clean audio spectrum..

(Very educational) Link to site.. www.electroschematics.com/325/stereo-encoder-high-separation/
www.iol.ie/~yellowbeard/eircomnew/vintage.html


Simple AM radio transmitters

Very simple AM MW bug type transmitter, 50-100mw (milliwatts)...

Link to site.. www.zen22142.zen.co.uk/Circuits/rf/amtx.htm

Tube type antique AM MW rangecaster for phono to radio and other applications, 100mw power output...

URL to site: antiqueradio.org/transmitter.htm

4 transistor 100mw legal AM MW broadcaster..

URL to site: www.techlib.com/electronics/amxmit.htm

2 tube AM MW rangecaster type circuit using a 4 pin powered oscillator crystal...

Link to site.. www.electronixandmore.com/project/10.html


Powerful AM radio transmitters (1 Watt+)

Small AM Shortwave transmitter by radiorob...

Circuit information thread

Famous Corsair transmitter schematic for Shortwave or high MW band


10 watt AM MW caster (uses FET)...


5-8 watt 100%+ modulated fully linear AM MW transmitter...


ChugAM project thread


More schematics on the way very soon, stay tuned.




Other good collections of AM/FM and other transmitter schematics/circuits...:


Lots of schematics for both AM/FM designs and even some stereo designs...
www.mf2fm.com/zfm/transmitter_circuits.php

embedded-system.net/radio-frequency-rf-circuits-06.html

www.satsleuth.com/Transmitters.htm

www.next.gr/rf/transmitters



More links on the way soon, stay tuned.

[rigmo]

IC QN8066 is top qualitiy.. better then BH or BA

[ogrevorbis]

Jan 17, 2020 17:46:28 GMT -6 rigmo said:

IC QN8066 is top qualitiy.. better then BH or BA

Very true. QN8007 is the absolute best however, but it's hard to solder.

There are a number of pre-made chinese transmitters that now use the QN8066. The generic 30 watter you can find on ebay does (the one with the yellow PCB). Also the 5-7 watt one that has the SD card slot. The one without the SD card that looks nearly identical has the KT0803L instead (which is garbage).

[rigmo]

Wich one use QN8007

[murena1970]

please where is possible to find QN8066 datasheet and possible application notes?

[chrish]

Here's our FM exciter circuit. We use the 5511 PLL IC and a 16F84A PIC to programme it. If anyone wants the PIC code, just let me know.