Omni-VI, Omni-VI+ (maybe others):
Make up a cable with a diode in series to connect the 87A "relay" line to a "Y" that plugs into the "TX OUT" and "TX EN" jacks on the Omni-VI. The "TX OUT" and "TX EN" are connected together by the "Y", the diode connects to the center conductor of the third leg of the "Y". The polarity of the diode has the cathode (band end) connected to the Y, diode anode goes to RELAY jack of Alpha. This will allow the TenTec "TX OUT" signal to key the amp when it enables the radio for transmit. This works on both CW QSK and SSB. DO NOT do this with any other amplifier unless you know that the keying line polarity of the amplifier is correct AND that the amp keying circuit is of very small current. This is only recommended for use with a Alpha 87A or 89 (they use PIN diodes for fast T/R switching). Thanks to Terry W6RU for this circuit (posted on the TenTec reflector).
All other radio/amp combinations, use the amplifier keying relay in the radio to the RCA jack on back of amp labeled RELAY.
