ED-4 is an add-on to the Radio / Antenna Selector ES-4.
Up to 3 radios connected to an ES-4 can control it and switchto the desired antenna when the band is changed on the radio.

ED-4 accepts 3 types of control signals:

  • BCD – Yaesu type or equivalent
  • Voltage control (0 – 8V) – ICOM type or equivalent
  • Kenwood information over an RS232 serial interface


ED-4 is connected to the ES-4 Antenna Selector and receives power from it
There are 3 DB9F connectors, where the control cables from up to 3 radios can be connected
When the band is changed on the selected radio, the designated antenna is automatically selected by ES-4
There are 3 LED’s, indicating which radio is selected and controls the ES-4
The Band Decoder comes with a bracket and can be attached to an existing ES-4, or can be installed independetly

Operation Independent of ES-4

There are 3 RJ12 jacks, outputting a BCD code for each radio that has an active control signal
For example, if 3 radios are connected to an ED-4: a Yaesu, an ICOM and a Kenwood, then the 3 jacks will output BCD information according to the band:
The BCD information is copied from Yaesu to the Jack No. 1 (this is the trivial case)
The Voltage information is converted to BCD and output to the Jack No. 2
The Kenwood radio is interrogated and its band information is sent in BCD format to Jack 3

There is also a DB-15F connector. It has normally high outputs for each band, with one pin going low, according to the band selected on the active radio.