Hi Greg,
746 pro being a modern transceiver, you wouldn't need a box like ARB-704 as the voltages involved are safe and compatible.
interfacing with your radio and Palstar LA-1K, there are two ways to do it.
1) connect the "SEND" & "ALC" ports on the back of the radio to the amplifier's "PTT" & "ALC" using RCA cables. - you would need to manually change the bands or set to use "RF Sensing" feature so that amplifier will detect upon transmit and set itself for use.
2) You can connect ACC-2 from the back of your radio to the LA-1K's radio interface (ICOM/Yaesu) port - A supported cable would be Ameritron DB-7DI. ?This cable would help the amplifier understand the band you have selected on the radio and make itself ready for transmission, without having to manually modify the band selection on the amplifier side or let amplifier do the job of understanding the frequency on transmit and make it do the hard work(if set for auto sensing) - ?Please set amplifier for band data cable use using the menu. The cable also provides the keying for the amplifier when you press PTT and also ALC feedback. ?Using band data cable doesn't set amplifier in transmit/operate mode automatically(for most bands) when you change bands - it will go into standby - you will have to tap Operate on touch panel. ?- #2 is how I use and feels safer than #1
The band data cable is not included with the amp - RCA cables also not included if I am not mistaken. But I am sure you have a pair lying around in your shack :)
you can find the band data cable from following sellers.
Kindly double check and please consider my 2 cents worth above as just pointers and confirm with other sources also as I hate to be remembered for wrong reasons - hehe!
if you need any more info, please feel free to ask.
73
Hari
