This universally usable control logic switch is needed in connection with a preamplifier, which does not possess a HF-VOX for transmit-receive-switching. The plate is built into the Transceiver and is that the transmitter switches on about 30 - 50 ms retarded. Thus the relais in the preamplifier have more strongly sufficient time for read-free switching and the preamplifier transistor is protected against destruction by HF.
The plate VVSTL can be built into almost all Transceivers.
If you should not want to make the installation, we make against small first cost, the installation in your Transceiver.