Ameritron ARB-704 PTT Linear interface
Each transceiver has an encoding output for an amplifier, but not all of those outputs are able to encode the high voltages or currents of an amplifier. High voltages or voltage spikes can destroy the encoding phase of the transceiver. To avoid this, an additional buffer relay such as the ARB-704 is used.
The Ameritron ARB-704 is a semiconductor coding buffer to control the PTT line of almost all amplifiers. It handles voltages of up to 200 V and currents up to 300 mA. This covers almost all the power amplifiers available on the market today. The minimum voltage of the amplifier can be positive or generative or even CA. The key buffer buffer against ground, works absolutely noise-free and is fast enough to handle QSK keying without changing the shape of the key pulse.
The input can be configured by internal jumpers for various voltage levels, positive or negative. This makes the ARB-704 usable with almost all transceivers. The input current is less than 1 mA. Very sensitive encoding outputs are also similar to those of the IC-706 can be managed.
The wiring and installation of the ARB-704 is very simple. The device is equipped with both RCA sockets (Cinch) and a 5-pin DIN socket for ready cables (see below). RCA sockets are used with standard RCA cable for PTT from TRx to ARB-704 and up to the amplifier. If you are using ALC, these connections bypass ARB-704, TRx and PA are connected directly to the ALC line.
Optionally WiMo offers ready-made cables for many transceivers. These cables use in most cases the ACC sockets on the back of the radio. The ARB-704 must be powered from 9 to 18 V CC, a separate CC cable is provided. Some ready-made cables absorb power directly from the transceiver.