Morse Key Over FM for Baofeng HT UV5R, S9 Plus.

It is a small circuit for sending morse code over FM through Baofeng HT like UV5R or S9 plus etc.

Basically sending Morse over FM [wide bandwidth] is something like illogical use of Bandwidth as Morse code can be send in a very narrow bandwidth with CW (Continuous Wave) which can travel a long distance with very much clear sound reception. However as an amateur radio operator we always try for new experiments, search fun during making new models and cultivating new circuit ideas.

I just want to make a small super easy circuit for sending Morse tone over FM through a very common cheap Chinese Handheld transceiver named Baofeng UV5R.

1. IC555 with Base
2. Resistors 100K, 1K [each 2 pcs], 10 Ohm.
3. Capacitor 0.01uf, 0.1uf, 4.7uf [each 1 pc]
4. Speaker 8 Ohm/ 1 Watt
5. Stereo Jack 3.5 mm and 2.5 mm (one each)
6. Push to On switch
7. DPDT switch
8. IC Board [small size, 3cm x 2cm will be fine]
9. 9V battery or appropriate power supply
10. For testing purpose you need at least one Baofeng HT and another FM transceiver. [2 Baofeng HT will be fine to test perfectly] I used with Baofeng UV5R and S9 Plus.

I am using 555 timer as astable multivibrator. The idea is simple, generating a Tone near 1-1.4 KHz and the output from pin 3 is supplied to mike input of Baofeng HT at the same time also PTT will be ON.

Always use IC Base, and connect the IC at the last step after carefully checking all connections.

Use different coloured wires for easy identifications.

A small speaker is also attached with the same output pin (Pin 3) as a sidetone for confirmation of producing Morse tone during pressing the Push to ON switch.

Using a DPDT , both the PTT and sidetone speaker is activated, and changing the switch to other position PTT will go Off.

The overall circuit can be fixed in a small plastic container (6.5cm x 4.5cm) including a 9V Battery.

First set two Transceiver at same frequency, say 147.100 MHz

Now connect the 2.5 stereo jack and 3.5 stereo jack to the HT from which you want to transmit the Morse code.

The Receiver set must be placed at least 3 meter away from the transmitting set.

First ON the receiving set.

Now ON the transmitting set.

If transmitting signal led is not seen in transmitting set change the DPDT position [if everything OK, then you should see that the transmitting led is on and on receiver set receiving signal led is on.]

Now press the push to on key and you must hear tone output from sidetone speaker of the circuit and from the receiver set.

After transmitting your Morse code, change the DPDT position, now your testing set is in receiving mode,receiving any morse code tone from another transmitting set, you will hear the tone from the sidetone speaker of the circuit. In this mode, there will be no PTT (Transmitting Led) light, instead there will be receiving Led on if you receive Morse code over FM from other Amateur HAM. [However this will be a very rare probability unless there is another amateur HAM who is interested sending Morse Code over FM, as I told befor that Sending Morse code is done by CW with very low bandwidth, which can travel very long distance, which is almost impossible in FM mode.

This is completely a fun experimental circuit. Morse code ia almost always transmitting through CW, low bandwidth signal so that with very low power it can travel a very long distance. Using Morse over FM is not done in practical as it FM is usually meant for complex audio like our voices which require a wider bandwidth.

Baofeng UV5R HT is not capable of transmitting Morse Code through CW as this HT does not have such hardware, it is meant for FM transmitting for Voice mainly. However in this circuit it is proven that this Model can transmit Morse code over FM, though the signal will not travel such long distance as CW mode transmission.