[CQ-Contest] External Relay Box question

[Tony Rogozinski]

I recently purchased a used Alpha 76PA which came with an ERB-1 External Relay Box sold by Burqhardt Amateur
Center.  I've been able to find out what this device actually does.  I was told by Burquhardt that it is to protect the
transmitter/ceiver from voltage spikes originating in the amplifier.  Can it be used during QSK operation or just PTT?
I'm not sure what's inside the unit.

Anyone have info?

Thanks

Tony W4OI/HK1AR