The Ultimate Morse Code Practice Oscillator For Straight Keys

This 3d printed Morse code oscillator runs on a 3 AAA batteries and puts out a realistic tone as though you where transmitting.
Connects via a 3.5mm audio jack (stereo) use the tip and the ground.

Like the old Boy Scout signal training this CPO produces both sound and light from the front and back. Adjustable volume and tone controls from 300-1000Hz.
Also has a headphone jack for private listening and practice.
All solder construction and ready to use upon arrival. (batteries included)
Knob Colors May Change From Red To White Depending On Stock...

The Scout CPO can also drive a positive keying transmitter up to 30V/500mA with the key jack. Standard 3.5mm stereo with tip and sleeve connector.

Plug your straight key into the KEY jack. This jack is a 3.5mm stereo using the tip and sleeve connections. With the key down adjust the volume and tone controls as needed. If using the headphone jack (SPKR stereo 3.5mm) ALWAYS turn the volume control fully counter-clockwise BEFORE plugging in. Then with the key down adjust the volume to a comfortable level. Optionally plug a positive keying transmitter into the KEY jack. The key jack also uses the tip (+) and sleeve (-) for keying the transmitter.

The main circuit uses a simple 555 timer as an oscillator using C1, R3, R5, and RV1 to determine the 300Hz-1000Hz range.

R7 and RV2 provide a volume control wich then drives Q2 to drive the speaker.
Q3 Provides a buffer transistor to key a transmitter. R4 limits the current and brightness to LEDS D1 & D2