The CTCSS system also known as PL tone is used to keep interferences from triggring repeater stations. It is also used to share the same frequency among several groups of users.

The CTCSS is based on a continuous low frequency tone which is transmitted along with the radio modulation. Because of this low frequency, the tone is usually not heard during the transmission. This frequency is between 67Hz to 250Hz. The following picture shows a 67Hz CTCSS signal:

To transmit a CTCSS tone you need an encoder. To detect a CTCSS tone your need a decoder.

You can set TED250 to work as a CTCSS tone encoder or decoder. There are 39 standard tones plus 8 non standard which can be very effective limiting non group users from accessing the repeater station.

TED250 also provides a voice filter to avoid the low frequency tone to be retransmited.

Due to its small size, TED250 can be installed inside of almost all mobile transceivers being a good option for equipments without this feature

Technical Characteristics

Encode and decode all the 39 standards and 8 non standards tones
High-pass voice filter to keep the repeater's audio clear
Dip-switch for tone selection
Can be remotely controlled if working with Elektra 2000 repeater controller
Modulation level adjustment (0 ~ 748mV)
Compatible with all brands of transceivers
Easy installation
A complete installation guide
Build in a high quality fiberglass PCB
Power source: 6.5V ~15V/10 mA.
Dimension: 43mm x 23mm x 10mm
One year warranty