TD-5 Subaudible Tone Module

Access all your favorite closed repeaters with our TD-5 CTCSS Encoder/Decoder

Our affordable CTCSS module is only 1-3/8 x 2-3/16 inches. It has many uses! This is a new version of our long-popular TD-3 module, with several new features, including crystal control for precise tone accuracy and a convenient DIP switch for tone selection without test equipment. It covers all standard sub audible tones. Its CMOS circuitry operates on +7 to 15 Vdc, drawing only 7 mA!

It's a general purpose tone encoder.

You can easily adapt your existing fm transceiver to access all your favorite closed repeaters. More and more repeaters are being changed to closed access because of interference. If you want to use those repeaters, you need to transmit the correct sub-audible tone. The TD-5 is a very convenient answer to this problem. If you have a transceiver which doesn't have a built-in CTCSS encoder, consider adding the TD-5. It is very economical, especially if you build the kit! And the tone level control on the board makes it easy to set the transmitter deviation.

If you only need one tone, you can select it with the DIP switch on the module. If you need several tones, our manual shows how you can set up a front panel switch to select between preset tones for several repeaters. A pot on the board allows you to set the transmitter deviation for the tone separately from your microphone audio. General information in the manual helps you install the module in any transceiver.

If you need a general purpose receiver decoder, the same TD-5 can be used to mute receive audio unless the proper tone is present on the signal. A convenient control line can be used to manually un-mute the receiver to allow monitoring the channel when desired, and a high pass filter gets rid of annoying tone buzz in the speaker audio. Unlike many such units, the TD-5 module handles both encode and decode! When used in a transceiver, your ptt line can be connected to the unit to switch between transmit and receive modes.

It's a closed access device for your repeater.

To block repeater transmission unless the user signal has the proper subaudible tone, an output transistor grounds the COS line between the receiver and the control board to prevent it from recognizing that the squelch is open. The TD-5 provides remote on/off capability when used with a DTMF controller. Whenever you need to defeat the TD-5 and allow anyone to access the repeater, simply ground the control line with any touch tone controller and the repeater becomes an open repeater.

It's a repeater tone encoder.

Most repeaters use CTCSS only on receive. But if you need to transmit a sub-audible tone as well, it is a simple matter of connecting the tone output of a second TD-5 module to the modulator input of your exciter. There is a handy tone output level control to set the transmitter deviation.

TD-5 CTCSS Decoder/Encoder Prices:

Wired/tested $69

Note: This unit uses many surface mount parts; so it is not available in kit form.